[Federal Register Volume 77, Number 163 (Wednesday, August 22, 2012)]
[Proposed Rules]
[Pages 50768-50854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-19659]



[[Page 50767]]

Vol. 77

Wednesday,

No. 163

August 22, 2012

Part II





Department of the Interior





Fish and Wildlife Service





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50 CFR Part 17





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Endangered and Threatened Wildlife and Plants; Endangered Status for 
Four Central Texas Salamanders and Designation of Critical Habitat; 
Proposed Rule

  Federal Register / Vol. 77 , No. 163 / Wednesday, August 22, 2012 / 
Proposed Rules  

[[Page 50768]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R2-ES-2012-0035; 4500030114]
RIN 1018-AY22


Endangered and Threatened Wildlife and Plants; Endangered Status 
for Four Central Texas Salamanders and Designation of Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to 
list the Austin blind salamander, Jollyville Plateau salamander, 
Georgetown salamander, and Salado salamander as endangered under the 
Endangered Species Act of 1973, as amended (Act), and propose to 
designate critical habitat for the species. In total, we propose to 
designate approximately 5,983 acres (2,440 hectares) as critical 
habitat for the four species. The proposed critical habitat is located 
in Travis, Williamson, and Bell Counties, Texas.

DATES: We will accept comments received or postmarked on or before 
October 22, 2012. Comments submitted electronically using the Federal 
eRulemaking Portal (see ADDRESSES section, below) must be received by 
11:59 p.m. Eastern Time on the closing date. We must receive requests 
for public hearings, in writing, at the address shown in the FOR 
FURTHER INFORMATION CONTACT section by October 9, 2012.
    Public Informational Sessions and Public Hearings: We will hold two 
public informational sessions and two public hearings on this proposed 
rule. We will hold a public informational session from 5:30 p.m. to 
6:30 p.m., followed by a public hearing from 7 p.m. to 8:30 p.m., in 
Round Rock, Texas, on Wednesday, September 5 (see ADDRESSES). We will 
hold a public informational session from 6:30 p.m. to 7:30 p.m., 
followed by a public hearing from 8 p.m. to 9:30 p.m., in Austin, 
Texas, on Thursday, September 6 (see ADDRESSES). Registration to 
present oral comments on the proposed rule at the public hearings will 
begin at the start of each informational session.

ADDRESSES: Document availability: You may obtain copies of the proposed 
rule on the Internet at http://www.regulations.gov at Docket No. FWS-
R2-ES-2012-0035 or by mail from the Austin Ecological Services Field 
Office (see FOR FURTHER INFORMATION CONTACT).
    The coordinates or plot points or both from which the maps are 
generated are included in the administrative record for this critical 
habitat designation and are available at (http://www.fws.gov/southwest/es/AustinTexas/), http://regulations.gov at Docket No. FWS-R2-ES-2012-
0035, and at the Austin Ecological Services Field Office (see FOR 
FURTHER INFROMATION CONTACT). Any additional tools or supporting 
information that we may develop for this critical habitat designation 
will also be available at the above locations.
    Written Comments: You may submit written comments by one of the 
following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. Search for Docket No. FWS-R2-ES-2012-0035. You may 
submit a comment by clicking on ``Comment Now!''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R2-ES-2012-0035ES-2012-0035; Division of 
Policy and Directives Management; U.S. Fish and Wildlife Service; 4401 
N. Fairfax Drive, MS 2042-PDM; Arlington, VA 22203.
    We request that you send comments only by the methods described 
above. We will post all comments on http://www.regulations.gov. This 
generally means that we will post any personal information you provide 
us (see the Information Requested section below for more information).
    Public informational sessions and public hearings: The September 5, 
2012, public informational session and hearing will be held at the 
Wingate by Wyndham Round Rock, 1209 N. IH 35 North, Exit 253 at Hwy 79, 
Round Rock, Texas 78664. The September 6, 2012, public informational 
session and hearing will be held at Thompson Conference Center, 2405 
Robert Dedman Drive, Room 2.102, Austin, Texas 78705. People needing 
reasonable accommodations in order to attend and participate in the 
public hearings should contact Adam Zerrenner, Field Supervisor, Austin 
Ecological Services Field Office, as soon as possible (see FOR FURTHER 
INFORMATION CONTACT).

FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, Field Supervisor, U.S. 
Fish and Wildlife Service, Austin Ecological Services Field Office, 
10711 Burnet Rd, Suite 200, Austin, TX 78758; by telephone 512-490-
0057; or by facsimile 512-490-0974. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Executive Summary

Why We Need to Publish a Rule

    This is a proposed rule to list the Austin blind salamander 
(Eurycea waterlooensis), Jollyville Plateau salamander (Eurycea 
tonkawae), Georgetown salamander (Eurycea naufragia), and Salado 
salamander (Eurycea chisholmensis) as endangered.
    With this rule, we are proposing to designate the following 
critical habitat for the four central Texas salamanders:
     Austin Blind salamander: 120 acres (49 hectares)
     Jollyville Plateau salamander: 4,460 acres (1,816 
hectares)
     Georgetown salamander: 1,031 acres (423 hectares)
     Salado salamander: 372 acres (152 hectares)
    The proposed critical habitat is located within Travis, Williamson, 
and Bell Counties, Texas.

The Basis for Our Action

    Under the Endangered Species Act, we can determine that a species 
is endangered or threatened based on any of the following five factors: 
(A) Destruction, modification, or curtailment of its habitat or range; 
(B) overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) inadequacy of 
existing regulatory mechanisms; or (E) other natural or manmade factors 
affecting the species continued existence. Based on our analysis under 
the five factors, we find that the four central Texas salamanders are 
primarily threatened by: factors A and D. Therefore, these species 
qualify for listing, which can only be done by issuing a rule.
    The Act requires that the Secretary designate critical habitat for 
a species, to the maximum extent prudent and determinable, concurrently 
with making a determination that a species is an endangered or 
threatened species. Section 4(b)(2) of the Act requires that the 
Secretary designate critical habitat based upon the best scientific 
data available, and after taking into consideration the economic 
impact, the impact on national security, and any other relevant impact 
of specifying any particular area as critical habitat. Section 4(b)(2) 
of the Act provides that the Secretary may exclude any area from 
critical habitat if he determines that the benefits of excluding that 
area outweigh the benefits of including it in the

[[Page 50769]]

designation, unless such an exclusion would result in the extinction of 
the species. This ``weighing'' of considerations under section 4(b)(2) 
of the Act is the next step in the designation process, in which the 
Secretary may consider particular areas for exclusion from the final 
designation.
    We are preparing an economic analysis. To ensure that we consider 
the economic impacts, we are preparing a draft economic analysis of the 
proposed critical habitat designations. We will use information from 
this analysis to inform the development of our final designation of 
critical habitat for these species.
    We will seek peer review. We are seeking comments from independent 
specialists to ensure that our critical habitat designations are based 
on scientifically sound data, assumptions, and analyses. We have 
invited these peer reviewers to comment on our specific assumptions and 
conclusions in these proposed critical habitat designations. Because we 
will consider all comments and information we receive during the 
comment period, our final determinations may differ from this proposal.

Information Requested

    We intend that any final action resulting from this proposed rule 
will be based on the best scientific and commercial data available and 
be as accurate and as effective as possible. Therefore, we request 
comments or information from other concerned governmental agencies, 
Native American tribes, the scientific community, industry, or any 
other interested parties concerning this proposed rule. We particularly 
seek comments concerning:
    (1) Biological, commercial trade, or other relevant data concerning 
any threats (or lack thereof) to these species and regulations that may 
be addressing those threats.
    (2) Additional information concerning the historical and current 
status, range, distribution, and population size of these species, 
including the locations of any additional populations of these species.
    (3) Any information on the biological or ecological requirements of 
these species, and ongoing conservation measures for these species and 
their habitats.
    (4) Current or planned activities in the areas occupied by the 
species and possible impacts of these activities on these species.
    (5) The reasons why we should or should not designate habitat as 
``critical habitat'' under section 4 of the Act (16 U.S.C. 1531 et 
seq.) including whether there are threats to the species from human 
activity, the degree of which can be expected to increase due to the 
designation, and whether that increase in threat outweighs the benefit 
of designation, such that the designation of critical habitat may not 
be prudent.
    (6) Specific information on:
    (a) The amount and distribution of the four central Texas 
salamanders' habitats,
    (b) What areas, that are currently occupied by these species, that 
contain features essential to their conservation,
    (c) Special management considerations or protection that may be 
needed in critical habitat areas we are proposing, including managing 
for the potential effects of climate change,
    (d) What areas not occupied at the time of listing are essential 
for the conservation of these species and why,
    (e) How subterranean populations of these four salamander species 
are distributed underground, and
    (f) The interconnectedness of salamander habitats in terms of 
hydrology, and whether salamanders are able to move between sites 
through underground aquifer conduits.
    (7) Land use designations and current or planned activities in the 
subject areas and their possible impacts on the four central Texas 
salamanders and on proposed critical habitat.
    (8) Information on the projected and reasonably likely impacts of 
climate change on the four central Texas salamanders and proposed 
critical habitat.
    (9) Any probable economic, national security, or other relevant 
impacts of designating any area that may be included in the final 
critical habitat designation; in particular, we seek information on any 
impacts on small entities or families, and the benefits of including or 
excluding areas that exhibit these impacts.
    (10) Whether any specific areas we are proposing for critical 
habitat designation should be considered for exclusion under section 
4(b)(2) of the Act, and whether the benefits of potentially excluding 
any specific area outweigh the benefits of including that area under 
section 4(b)(2) of the Act; for example, areas that have a 10(a)(1)(B) 
permit and habitat conservation plan (HCP) that covers any of these 
salamanders may be considered for exclusion (potentially including the 
Four Points HCP that covers Jollyville Plateau salamanders).
    (11) Whether we could improve or modify our approach to designating 
critical habitat in any way to provide for greater public participation 
and understanding, or to better accommodate public concerns and 
comments.
    Please note that submissions merely stating support for or 
opposition to the action under consideration without providing 
supporting information, although noted, will not be considered in 
making a determination, as section 4(b)(1)(A) of the Act directs that 
determinations as to whether any species is an endangered or 
threatenedspecies must be made ``solely on the basis of the best 
scientific and commercial data available.''
    You may submit your comments and materials concerning this proposed 
rule by one of the methods listed in the ADDRESSES section. We request 
that you send comments only by the methods described in the ADDRESSES 
section.
    If you submit information via http://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on http://www.regulations.gov. 
Please include sufficient information with your comments to allow us to 
verify any scientific or commercial information you include.
    Comments and materials we receive, as well as supporting 
documentation we used in preparing this proposed rule, will be 
available for public inspection on http://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, Austin Ecological Services Field Office (see FOR 
FURTHER INFORMATION CONTACT).

Previous Federal Actions

    The Austin blind and Salado salamanders were included in nine 
Candidate Notices of Review (67 FR 40657, June 13, 2002; 69 FR 24876, 
May 4, 2004; 70 FR 24870, May 11, 2005; 71 FR 53756, September 12, 
2006; 72 FR 69034, December 6, 2007; 73 FR 75176, December 10, 2008; 74 
FR 57804, November 9, 2009; 75 FR 69222, November 10, 2010; 76 FR 
66370, October 26, 2011). The listing priority number has remained at 2 
throughout the reviews for both species, indicating that threats to the 
species were both imminent and high in magnitude. In addition, on May 
11, 2004, the Service received a petition from the Center for 
Biological Diversity to list 225 species we previously had identified 
as

[[Page 50770]]

candidates for listing in accordance with section 4 of the Act, 
including the Austin blind and Salado salamanders.
    The Jollyville Plateau salamander was petitioned to be listed as an 
endangered species on June 13, 2005, by Save Our Springs Alliance. 
Action on this petition was precluded by court orders and settlement 
agreements for other listing actions until 2006. On February 13, 2007, 
we published a 90-day petition finding (72 FR 6699) in which we 
concluded that the petition presented substantial information 
indicating that listing may be warranted. On December 13, 2007, we 
published the 12-month finding (72 FR 71040) on the Jollyville Plateau 
salamander, which concluded that listing was warranted, but precluded 
by higher priority actions. The Jollyville Plateau salamander was 
subsequently included in all of our annual Candidate Notices of Review 
(73 FR 75176, December 10, 2008; 74 FR 57804, November 9, 2009; 75 FR 
69222, November 10, 2010; 76 FR 66370, October 26, 2011). Throughout 
the three reviews, the listing priority number has remained at 8, 
indicating that threats to the species were imminent, but moderate to 
low in magnitude. On September 30, 2010, the Jollyville Plateau 
salamander was petitioned to be emergency listed by Save Our Springs 
Alliance and Center for Biological Diversity. We issued a petition 
response letter to Save Our Springs Alliance and Center for Biological 
Diversity on December 1, 2011, which stated that emergency listing a 
species is not a petitionable action under the Administrative Procedure 
Act or the Act; therefore, we treat a petition requesting emergency 
listing solely as a petition to list a species under the Act.
    The Georgetown salamander was included in 10 Candidate Notices of 
Review (66 FR 54808, October 30, 2001; 67 FR 40657, June 13, 2002; 69 
FR 24876, May 4, 2004; 70 FR 24870, May 11, 2005; 71 FR 53756, 
September 12, 2006; 72 FR 69034, December 6, 2007; 73 FR 75176, 
December 10, 2008; 74 FR 57804, November 9, 2009; 75 FR 69222, November 
10, 2010; 76 FR 66370, October 26, 2011). In the 2008 review, the 
listing priority number was lowered from 2 to 8, indicating that 
threats to the species were imminent, but moderate to low in magnitude. 
This reduction in listing priority number was primarily due to the land 
acquisition and conservation efforts of the Williamson County 
Conservation Foundation. In addition, the Georgetown salamander was 
petitioned by the Center for Biological Diversity to be listed as an 
endangered species on May 11, 2004, but at that time, it was already a 
candidate species whose listing was precluded by higher priority 
actions.

Endangered Status for the Four Central Texas Salamanders

Background

    It is our intent to discuss below only those topics directly 
relevant to the proposed listing of the Austin blind salamander, 
Jollyville Plateau salamander, Georgetown salamander, and Salado 
salamander as endangered in this section of the proposed rule.
Species Information
    All four central Texas salamanders (Austin blind, Jollyville 
Plateau, Georgetown, and Salado salamanders) are neotenic (do not 
transform into a terrestrial form) members of the family 
Plethodontidae. Plethodontid salamanders comprise the largest family of 
salamanders within the Order Caudata, and are characterized by an 
absence of lungs (Petranka 1998, pp. 157-158). As neotenic salamanders, 
they retain external feathery gills and inhabit aquatic habitats 
(springs, spring-runs, and wet caves) throughout their lives 
(Chippindale et al. 2000, p. 1). In other words, all four of these 
salamanders are entirely aquatic and respirate through gills. Also, all 
adult salamanders of these four species are about 2 inches (in) (5 
centimeters (cm)) long (Chippindale et al. 2000, pp. 32-42; Hillis et 
al. 2001, p. 268).
    Each species inhabits water of high quality with a narrow range of 
conditions (for example, temperature, pH, and alkalinity) maintained by 
the Edwards Aquifer. All four species depend on this water from the 
Edwards Aquifer in sufficient quantity and quality to meet their life-
history requirements for survival, growth, and reproduction. The 
Edwards Aquifer is a karst aquifer characterized by open chambers such 
as caves, fractures, and other cavities that were formed either 
directly or indirectly by dissolution of subsurface rock formations. 
Water for the salamanders is provided by infiltration of surface water 
through the soil or recharge features (caves, faults, fractures, 
sinkholes, or other open cavities) into the Edwards Aquifer, which 
discharges from springs as groundwater (Schram 1995, p. 91). The 
habitat of one species (Austin blind salamander) occurs in the Barton 
Springs Segment of the Edwards Aquifer, while the habitats of the three 
other species occur in the Northern Segment of the Edwards Aquifer. The 
recharge and contributing zones of these segments of the Edwards 
Aquifer are found in portions of Travis, Williamson, Blanco, Bell, 
Burnet, Lampasas, Mills, Hays, Coryell, and Hamilton Counties, Texas 
(Hill Country Foundation 1995, p. 1). The three salamander species that 
occur in the Northern Segment of the Edwards Aquifer (Jollyville 
Plateau, Georgetown, and Salado salamanders) have very similar external 
morphology. Because of this, they were previously believed to be the 
same species; however, molecular evidence strongly indicates that there 
is a high level of divergence between the three groups (Chippindale et 
al. 2000, pp. 15-16).
    The four central Texas salamander species spend varying portions of 
their life within their surface (in or near spring openings and pools 
as well as spring runs) and subsurface (within caves or other 
underground areas within the Edwards Aquifer) habitats. They travel an 
unknown depth into interstitial spaces (empty voids between rocks) 
within the spring or streambed substrate that provide foraging habitat 
and protection from predators and drought conditions (Cole 1995, p. 24; 
Pierce and Wall 2011, pp. 16-17). They may also use deeper passages of 
the aquifer that connect to the spring opening (Dries 2011, City of 
Austin (COA), pers. comm.). This behavior makes it difficult to 
accurately estimate population sizes, as only salamanders on the 
surface can be regularly monitored. Therefore, the status of subsurface 
populations is largely unknown, making it difficult to assess the 
effects of threats on the subsurface populations and their habitat.
    The Austin blind, Jollyville Plateau, Georgetown, and Salado 
salamanders have much in common. All four species are entirely aquatic 
throughout each portion of their life cycles and highly dependent on 
water from the Edwards Aquifer in sufficient quantity and quality to 
meet their life-history requirements for growth, survival, and 
reproduction. Although detailed dietary studies are lacking for these 
four salamander species, their diets are presumed to be similar to 
other Eurycea species, consisting of small aquatic invertebrates such 
as amphipods, copepods, isopods, and insect larvae [reviewed in COA 
2001, pp. 5-6]. The four central Texas salamanders also share similar 
predators, which include centrarchid fish (carnivorous freshwater fish 
belonging to the sunfish family), crayfish, and large aquatic insects 
(Pierce and Wall 2011, pp. 18-20; Bowles et al. 2006, p. 117; Cole 
1995, p. 26). Because eggs are very rarely found on the surface, it is 
believed that these salamanders deposit their eggs underground for 
protection (O'Donnell et al. 2005, p. 18). The detection of

[[Page 50771]]

juveniles in all seasons suggests that reproduction occurs year-round 
(Bendik 2011a, p. 26; Hillis et al. 2001, p. 273).
    Dispersal patterns through streams or aquifers for these four 
salamander species are relatively unknown. However, one study of other 
closely related Eurycea species in the southeastern portion of central 
Texas found that populations of salamanders are genetically isolated 
from one another and neither aquifers nor streams serve as dispersal 
corridors (Lucas et al. 2009, pp. 1,315-1,316).
    On the other hand, some evidence suggests that the four Texas 
salamanders may be able to travel some distance through subsurface 
aquifer conduits. Recent genetic work on the Jollyville Plateau 
salamander showed evidence of gene flow between sites that are not 
connected by surface flow (Chippindale 2010, pp. 9, 18-22). This study 
suggests that central Texas salamanders are regionally isolated, but 
populations within those regions have some level of dispersal ability 
through the subsurface habitat. For example, the Austin blind 
salamander is believed to occur underground throughout the entire 
Barton Springs complex (Dries 2011, pers. comm.). The spring habitats 
used by salamanders of the Barton Springs complex are not connected on 
the surface, so the Austin blind salamander population extends at least 
984 feet (ft) (300 meters (m)) underground, as this is the approximate 
distance between the farthest two outlets within the Barton Springs 
complex known to be occupied by the species.
    Due to the similar life history of the other three Eurycea species 
considered here, it is plausible that populations of these species 
could also extend this distance through subterranean habitat. Dye-trace 
studies have demonstrated that some Jollyville Plateau salamander sites 
located miles apart are connected hydrologically (Hauwert and Warton 
1997), but it remains unclear if salamanders are able to travel between 
those sites. Also, in Salado, a large underground conduit conveys 
groundwater from the area under the Stagecoach Hotel to Big Boiling 
Spring (Mahler 2012, U.S. Geological Survey, pers. comm.). 
Additionally, in Barton Springs, a mark and recapture study failed to 
document the movement of endangered Barton Springs salamanders (Eurycea 
sosorum) between any of the springs in the Barton Springs complex 
(Dries 2012, pers. comm.), although this study has only recently begun 
and is relatively small in scope. In conclusion, there is some evidence 
that populations could be connected through subterranean habitat, 
although dispersal patterns and the actual nature of connectivity are 
largely unknown.
    Because the hydrology of central Texas is very complex and 
information on the hydrology of specific spring sites is largely 
unknown, we are seeking information on spring hydrology and salamander 
dispersal during the public comment period (see ``Information 
Requested'' above).
    Each species is discussed in more detail below.
Austin Blind Salamander
    The Austin blind salamander has a pronounced extension of the 
snout, no external eyes, and weakly developed tail fins. In general 
appearance and coloration, the Austin blind salamander is more similar 
to the Texas blind salamander (Eurycea rathbuni) that occurs in the 
Southern Segment of the Edwards Aquifer than its sympatric (occurring 
within the same range) species, the Barton Springs salamander. The 
Austin blind salamander has a reflective, lightly pigmented skin with a 
pearly white or lavender appearance (Hillis et al. 2001, p. 271). 
Before the Austin blind salamander was formally described, juvenile 
salamanders were sighted occasionally in Barton Springs, and thought to 
be a variation of the Barton Springs salamander. It was not until 2001, 
that enough specimens were available to formally describe these 
juveniles as a separate species using morphological and genetic 
characteristics (Hillis et al. 2001, p. 267). Given the reduced eye 
structure of the Austin blind salamander, and the fact that it is 
rarely seen at the water's surface (Hillis et al. 2001, p. 267), this 
salamander is thought to be more subterranean than the surface-dwelling 
Barton Springs salamander.
    The Austin blind salamander occurs in Barton Springs in Austin, 
Texas. These springs are fed by the Barton Springs Segment of the 
Edwards Aquifer. This segment covers roughly 155 square miles (mi) (401 
square kilometers (km)) from southern Travis County to northern Hays 
County, Texas (Smith and Hunt 2004, p. 7). It has a storage capacity of 
over 300,000 acre-feet. The contributing zone for the Barton Springs 
Segment of the Edwards Aquifer that supplies water to the salamander's 
spring habitat extends into Travis, Blanco, and Hays Counties, Texas 
(Ross 2011, p. 3).
    The Austin blind salamander is found in three of the four Barton 
Springs outlets in the City of Austin's Zilker Park, Travis County, 
Texas: Main (Parthenia) Springs, Eliza Springs, and Sunken Garden (Old 
Mill or Zenobia) Springs. The Main Springs provides water for the 
Barton Springs Pool, and is operated by the City of Austin as a public 
swimming pool. These spring sites have been significantly modified for 
human use. The area around Main Springs was impounded in the late 1920s 
to create Barton Springs Pool. Flows from Eliza and Sunken Garden 
Springs are also retained by concrete structures, forming small pools 
on either side of Barton Springs Pool (COA 1998, p. 6; Service 2005, p. 
1.6-25). The Austin blind salamander has not been observed at the 
fourth Barton Springs outlet, known as Upper Barton Springs (Hillis et 
al. 2001, p. 273). For more information on habitat, see the ``Proposed 
Critical Habitat Designation for the Four Central Texas Salamanders'' 
section of this proposed rule.
    From January 1998 to December 2000, there were only 17 documented 
observations of the Austin blind salamander. During this same time-
frame, 1,518 Barton Springs salamander observations were made (Hillis 
et al. 2001, p. 273). The abundance of Austin blind salamanders 
increased slightly from 2002-2006, but fewer observations have been 
made in more recent years (2009-2010) (COA 2011a, pp. 51-52). When they 
are observed, Austin blind salamanders occur in relatively low numbers 
(COA 2011a, pp. 51-52). Most of the Austin blind salamanders that were 
observed during these surveys were juveniles (less than 1 in (2.5 cm) 
in total length) (Hillis et al. 2001, p. 273). Although the technology 
to safely and reliably mark salamanders for individual recognition has 
recently been developed (O'Donnell et al. 2008, p. 3), population 
estimates for this species have not been undertaken, because surveying 
within the Edwards Aquifer is not possible at the current time. 
However, population estimates are possible for aquifer-dwelling species 
using genetic techniques, and one such study is planned for the Austin 
blind salamander in the near future (Texas Parks and Wildlife 
Department (TPWD) 2011a, p. 11).
Jollyville Plateau Salamander
    Surface-dwelling populations of Jollyville Plateau salamanders have 
large, well-developed eyes; wide, yellowish heads; blunt, rounded 
snouts; dark greenish-brown bodies; and bright yellowish-orange tails 
(Chippindale et al. 2000, pp. 33-34). Some cave forms of Jollyville 
Plateau salamanders exhibit cave-associated morphologies, such as eye 
reduction, flattening of the head, and dullness or loss of color 
(Chippindale et al. 2000, p. 37). Genetic analysis suggests a taxonomic 
split

[[Page 50772]]

within this species that appears to correspond to major geologic and 
topographic features of the region (Chippindale 2010, p. 2). 
Chippindale (2010, pp. 5, 8) concluded that the Jollyville Plateau 
salamander exhibits a strong genetic separation between two lineages 
within the species: A ``Plateau'' clade that occurs in the Bull Creek, 
Walnut Creek, Shoal Creek, Brushy Creek, South Brushy Creek, and 
southeastern Lake Travis drainages; and a ``peripheral'' clade that 
occurs in the Buttercup Creek and northern Lake Travis drainages 
(Chippindale 2010, pp. 5-8). The study also suggests this genetic 
separation may actually represent two species (Chippindale 2010, pp. 5, 
8). However, a formal, peer-reviewed description of the two possible 
species has not been published. We therefore do not recognize a 
separation of the Jollyville Plateau salamander into two species 
because this split has not been recognized by the scientific community.
    The Jollyville Plateau salamander occurs in the Jollyville Plateau 
and Brushy Creek areas of the Edwards Plateau in Travis and Williamson 
Counties, Texas (Chippindale et al. 2000, pp. 35-36; Bowles et al. 
2006, p. 112; Sweet 1982, p. 433). Upon classification as a species, 
Jollyville Plateau salamanders were known from Brushy Creek and, within 
the Jollyville Plateau, from Bull Creek, Cypress Creek, Long Hollow 
Creek, Shoal Creek, and Walnut Creek drainages (Chippindale et al. 
2000, p. 36). Since it was described, the Jollyville Plateau salamander 
has also been documented within the Lake Creek drainage (O'Donnell et 
al. 2006, p. 1). Cave-dwelling Jollyville Plateau salamanders are known 
from 1 cave in the Cypress Creek drainage and 12 caves in the Buttercup 
Creek cave system in the Brushy Creek drainage (Chippindale et al. 
2000, p. 49; Russell 1993, p. 21; Service 1999, p. 6; HNTB 2005, p. 
60).
    The Jollyville Plateau salamander's spring-fed habitat is typically 
characterized by a depth of less than 1 foot (ft) (0.3 meters (m)) of 
cool, well oxygenated water (COA 2001, p. 128; Bowles et al. 2006, p. 
118) supplied by the underlying Northern Segment of the Edwards Aquifer 
(Cole 1995, p. 33). The aquifer that feeds this salamander's habitat is 
generally small, shallow, and localized (Chippindale et al. 2000; p. 
36, Cole 1995, p. 26). Jollyville Plateau salamanders are typically 
found near springs or seep outflows and likely require constant 
temperatures (Sweet 1982, pp. 433-434; Bowles et al. 2006, p. 117). 
Salamander densities are higher in pools and riffles and in areas with 
rubble, cobble, or boulder substrates rather than on solid bedrock (COA 
2001, p. 128; Bowles et al. 2006, pp. 114-116). Surface-dwelling 
Jollyville Plateau salamanders also occur in subsurface habitat within 
the underground aquifer (COA 2001, p. 65; Bowles et al. 2006, p. 118). 
For more on habitat, see the ``Proposed Critical Habitat Designation 
for the Four Central Texas Salamanders'' of this proposed rule.
    Some Jollyville Plateau salamander populations have experienced 
decreases in abundance in recent years. City of Austin survey data 
indicate that four of the nine sites that were regularly monitored by 
City of Austin staff between December 1996 and January 2007 had 
statistically significant declines in salamander abundance over 10 
years (O'Donnell et al. 2006, p. 4). The average number of salamanders 
counted at each of these 4 sites declined from 27 salamanders counted 
during surveys from 1996 to 1999 to 4 salamanders counted during 
surveys from 2004 to 2007. In 2007, monthly mark-recapture surveys were 
conducted in concert with surface counts at three sites in the Bull 
Creek watershed (Lanier Spring, Lower Rieblin, and Wheless Spring) over 
a 6-to-8-month period to obtain surface population size estimates and 
detection probabilities for each site (O'Donnell et al. 2008, p. 11). 
Surface population estimates at Lanier Spring varied from 94 to 249, 
surface population estimates at the Lower Rieblin site varied from 78 
to 126, and surface population estimates at Wheless Spring varied from 
187 to 1,024 (O'Donnell et al. 2008, pp. 44-45). These numbers remained 
fairly consistent in more recent population estimates for the three 
sites (Bendik 2011a, p. 22).
Georgetown Salamander
    The Georgetown salamander is characterized by a broad, relatively 
short head with three pairs of bright-red gills on each side behind the 
jaws, a rounded and short snout, and large eyes with a gold iris. The 
upper body is generally grayish with varying patterns of melanophores 
(cells containing brown or black pigments called melanin) and 
iridophores (cells filled with iridescent pigments called guanine), 
while the underside is pale and translucent. The tail tends to be long 
with poorly developed dorsal and ventral fins that are golden-yellow at 
the base, cream-colored to translucent toward the outer margin, and 
mottled with melanophores and iridophores. Unlike the Jollyville 
Plateau salamander, the Georgetown salamander has a distinct dark 
border along the lateral margins of the tail fin (Chippindale et al. 
2000, p. 38). As with the Jollyville Plateau salamander, the Georgetown 
salamander has recently discovered cave-adapted forms with reduced eyes 
and pale coloration (TPWD 2011a, p. 8).
    The Georgetown salamander is known from springs along five 
tributaries (South, Middle, and North Forks; Cowan Creek; and Berry 
Creek) to the San Gabriel River (Pierce 2011a, p. 2) and from three 
caves (aquatic, subterranean locations) in Williamson County, Texas. A 
groundwater divide between the South Fork of the San Gabriel River and 
Brushy Creek to the south likely creates the division between the 
ranges of the Jollyville Plateau and Georgetown salamanders (Williamson 
County 2008, p. 3-34). The Service is currently aware of 16 Georgetown 
salamander localities. This species has not been observed in recent 
years at two locations (San Gabriel Spring and Buford Hollow), despite 
several visual survey efforts to find it (Pierce 2011b,c, Southwestern 
University, pers. comm.). The current population status is unknown for 
four sites due to restricted access (Cedar Breaks, Shadow Canyon, Hogg 
Hollow Spring, and Bat Well). Georgetown salamanders continue to be 
observed at the remaining 10 sites (Swinbank Spring, Knight Spring, 
Twin Springs, Hogg Hollow Spring, Cowan Creek Spring, Cedar Hollow, 
Cobbs Cavern Spring, Cobbs Well, Walnut Spring, and Water Tank Cave) 
(Pierce 2011c, pers. comm.; Gluesenkamp 2011a, TPWD, pers. comm.). 
Recent mark-recapture studies suggest a population size of 100 to 200 
adult salamanders at Twin Springs, with a similar population estimate 
at Swinbank Spring (Pierce 2011a, p. 18). Population sizes at other 
sites are unknown, but visual surface counts result in comparatively 
low numbers (Williamson County 2008, pp. 3-35). There are numerous 
other springs in Williamson County that may support Georgetown 
salamander populations, but private land ownership prevents 
investigative surveys (Williamson County 2008, pp. 3-35).
    Surface-dwelling Georgetown salamanders inhabit spring runs, 
riffles, and pools with gravel and cobble rock substrates (Pierce et 
al. 2010, pp. 295-296). This species prefers larger cobble and boulders 
to use as cover (Pierce et al. 2010, p. 295). Salamanders are found 
within 164 ft (50 m) of a spring opening (Pierce et al. 2011a, p. 4), 
but they are most abundant within the first 16.4 ft (5 m) (Pierce et 
al. 2010, p. 294). Individuals do not exhibit much movement throughout 
the year (Pierce et al. 2010, p. 294). The water chemistry

[[Page 50773]]

of Georgetown salamander habitat is constant year-round in terms of 
temperature and dissolved oxygen (Pierce et al. 2010, p. 294, Biagas et 
al. in review, p. 8). Little is known about the ecology of Georgetown 
salamanders that occupy the cave sites (Cobbs Cavern, Bat Well, and 
Water Tank Cave) where this species is known to occur or the quality 
and extent of their subterranean habitats. For more on habitat, see the 
``Proposed Critical Habitat Designation for the Four Central Texas 
Salamanders'' section of this proposed rule.
Salado Salamander
    The Salado salamander has reduced eyes compared to other spring-
dwelling Eurycea species in north-central Texas and lacks well-defined 
melanophores. It has a relatively long and flat head, and a blunt and 
rounded snout. The upper body is generally grayish-brown with a slight 
cinnamon tinge and an irregular pattern of tiny, light flecks. The 
underside is pale and translucent. The posterior portion of the tail 
generally has a well-developed dorsal fin, but the ventral tail fin is 
weakly developed (Chippindale et al. 2000, p. 42).
    The Salado salamander is known historically from four spring sites 
near the village of Salado, Bell County, Texas: Big Boiling Springs 
(also known as Main, Salado, or Siren Springs), Lil' Bubbly Spring, 
Lazy Days Fish Farm Spring, and Robertson Springs (Chippindale et al. 
2000, p. 43; TPWD 2011a, pp. 1-2). These springs bubble up through 
faults in the Northern Segment of the Edwards Aquifer and associated 
limestone along Salado Creek (Brune 1975, p. 31). The four spring sites 
all contribute to Salado Creek. Under Brune's (1975, p. 5) definition, 
which identifies springs depending on flow, all sites are considered 
small (4.5 to 45 gallons per minute (17 to 170 liters per minute)) to 
medium springs (45 to 449 gallons per minute (170 to 1,1700 liters per 
minute)). Several other spring sites (Big Bubbly Springs, Critchfield 
Springs, and Anderson Springs) are located downstream from Big Boiling 
Springs and Robertson Springs. These springs have been surveyed by TPWD 
periodically since June 2009, but no salamanders have been found 
(Gluesenkamp 2010, pers. comm.). In August 2009, TPWD discovered a 
population of salamanders at a new site (Solana Spring 1) 
farther upstream on Salado Creek in Bell County, Texas (TPWD 2011a, p. 
2). Salado salamanders were recently confirmed at two other spring 
sites (Cistern and Hog Hollow Springs) farther upstream on the Salado 
Creek in March 2010 (TPWD 2011a, p. 2). In total, the Salado salamander 
is known from seven springs. A groundwater divide between Salado Creek 
and Berry Creek to the south likely creates a division between the 
ranges of the Georgetown and Salado salamander (Williamson County 2008, 
p. 3-34).
    Of the four salamander species, Salado salamanders are observed the 
least and are therefore less understood. Biologists were unable to 
observe this species in its type locality (location from which a 
specimen was first collected and identified as a species) despite over 
20 visits to Big Boiling Springs that occurred between 1991 and 1998 
(Chippindale et al. 2000, p. 43). Likewise, TPWD surveyed this site 
weekly from June 2009 until May 2010, and found one salamander 
(Gluesenkamp 2010, pers. comm.) at a spring outlet locally referred to 
as ``Lil' Bubbly'' located just upstream from Big Boiling Springs. One 
additional unconfirmed sighting of a Salado salamander in Big Boiling 
Springs was reported in 2008, by a citizen of Salado, Texas. In 2009, 
TPWD was granted access to Robertson Springs to survey for the Salado 
salamander. This species was reconfirmed at this location in February 
2010 (Gluesenkamp 2010, pers. comm.). Salado salamander populations 
appear to be larger at spring sites upstream of the Village of Salado, 
probably due to the higher quality of the habitat (Gluesenkamp 2011c, 
pers. comm.). For more on habitat, see the ``Proposed Critical Habitat 
Designation for the Four Central Texas Salamanders'' section of this 
proposed rule.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for adding 
species to the Federal Lists of Endangered and Threatened Wildlife and 
Plants. Under section 4(a)(1) of the Act, we may list a species based 
on any of the following five factors: (A) The present or threatened 
destruction, modification, or curtailment of its habitat or range; (B) 
overutilization for commercial, recreational, scientific, or 
educational purposes; (C) disease or predation; (D) the inadequacy of 
existing regulatory mechanisms; and (E) other natural or manmade 
factors affecting its continued existence. Listing actions may be 
warranted based on any of the above threat factors, singly or in 
combination. Each of these factors is discussed below.

Factor A. The Present or Threatened Destruction, Modification, or 
Curtailment of Its Habitat or Range

    Habitat modification, in the form of degraded water quality and 
quantity and disturbance of spring sites, is the primary threat to the 
four central Texas salamander species. Water quality degradation in 
salamander habitat has been cited as the top concern in several studies 
(Chippindale et al. 2000, pp. 36, 40, 43; Bowles et al. 2006, pp. 118-
119; O'Donnell et al. 2006, pp. 45-50), because these salamanders spend 
their entire life cycle in water. All of the species have evolved under 
natural aquifer conditions both underground and as the water discharges 
from natural spring outlets. Deviations from that high water quality 
have detrimental effects on salamander ecology, because the aquatic 
habitat can be rendered unsuitable for salamanders by changes in water 
chemistry, quantity, and flow patterns. Substrate modification is also 
a major concern for the salamander species (COA 2001, pp. 101, 126; 
Geismar 2005, p. 2; O'Donnell et al. 2006, p. 34). Unobstructed 
interstitial space (the space between the rocks) is critical to habitat 
of all four salamander species, because it provides cover from 
predators and habitat for macroinvertebrate prey items. When the 
interstitial spaces become compacted or filled with fine sediment, the 
amount of available foraging habitat and protective cover for 
salamanders is reduced (Welsh and Ollivier 1998, p. 1,128).
    Threats to the habitat of the four central Texas salamanders may 
target only the surface habitat, only the subsurface habitat, or both 
habitat types. For example, substrate modification degrades the surface 
springs and spring-runs but does not impact the subsurface environment, 
while water quality degradation impacts both the surface and subsurface 
habitats. Because of their ability to retreat to the subsurface 
habitat, the four central Texas salamander species may be able to 
persist through surface habitat degradation. For example, drought 
conditions are common to the region, and these salamanders' ability to 
retreat underground may be an evolutionary adaptation to such natural 
conditions (Bendik 2011a, pp. 31-32). However, we do not fully 
understand the relative importance of the surface and subsurface 
habitats to salamander populations. The best available scientific 
evidence suggests that surface habitats are important for prey 
availability and individual growth. Prey availability for carnivores is 
low underground due to the lack of sunlight

[[Page 50774]]

and primary production (Hobbs and Culver 2009, p. 392). In addition, 
length measurements taken during a City of Austin mark-recapture study 
at Lanier Spring demonstrated that Jollyville Plateau salamanders had 
negative growth during a 10-month period of retreating to the 
subsurface from 2008 to 2009 (Bendik 2011b, COA, pers. comm.). 
Therefore, threats to surface habitat at a given site may not extirpate 
any populations of these salamander species, but this type of habitat 
degradation may severely limit population growth and increase the 
species' overall risk of extinction from other threats.
    The majority of the discussion below under Factor A focuses on 
evaluating the nature and extent of stressors related to urbanization 
within the watershed, the primary source of water quality degradation. 
Additionally, other sources of habitat destruction and modification 
will be addressed. These include physical habitat modification from 
human activities and feral hogs, and environmental events, such as 
flooding and drought.

Urbanization Within the Watershed

    The ranges of the four salamander species reside within 
increasingly urbanized areas of Travis, Williamson, and Bell Counties 
that are experiencing rapid human population growth. For example, the 
population of the City of Austin grew from 251,808 people in 1970, to 
656,562 people in 2000. By 2007, the population had grown to 735,088 
people (COA 2007a, p. 1). This represents a 192 percent increase over 
the 37-year period. The human population within the City of Georgetown, 
Texas, was 28,339 in 2000, and increased to 47,380 by January 2008 
(City of Georgetown 2008, pp. 3.3-3.5). The human population is 
expected to exceed 225,000 by 2033 (City of Georgetown 2008, p. 3.5), 
which would be a 375 percent increase over a 33-year period. Population 
projections from the Texas State Data Center (2008, p. 1) estimate that 
Travis County will increase in population from 812,280 in 2000, to 
1,498,569 in 2040. This would be an 84 percent increase in the human 
population size over this 40-year period. The Texas State Data Center 
also estimates an increase in human population in Williamson County 
from 249,967 in 2000, to 1,742,619 in 2040. This would represent a 597 
percent increase over a 40-year timeframe. The human population is not 
increasing as rapidly in the range of the Salado salamander, but growth 
is occurring. Population projections from the Texas State Data Center 
(2009, p. 19) estimate that Bell County will increase in population 
from 237,974 in 2000, to 397,741 in 2040, a 67 percent increase over 
the 40-year period. By comparison, the national United States' 
population is expected to increase from 310,233,000 in 2010, to 
405,655,000 in 2040, which is about a 24 percent increase over the 30-
year period (U.S. Census Bureau 2012, p. 1). Growing human populations 
increase demand for residential and commercial development, drinking 
water supply, wastewater disposal, flood control, and other municipal 
goods and services that alter the environment, often degrading 
salamander habitat by changing hydrologic regimes, and affecting the 
quantity and quality of water resources.
    As development increases within the watersheds, more opportunities 
exist for the detrimental effects of urbanization to impact salamander 
habitat. Urban development upstream of salamander habitat leads to 
various stressors on spring systems, including increased flow 
velocities, increased sedimentation, increased contamination, changes 
in stream morphology and water chemistry, and decreases in groundwater 
recharge.
    Several researchers have examined the negative impact of 
urbanization on stream salamander habitat by making connections between 
salamander abundances and levels of development within the watershed. 
In 1972, Orser and Shure (p. 1,150) were among the first biologists to 
show a decrease in stream salamander density with increasing urban 
development. A similar relationship between salamanders and 
urbanization was found in North Carolina (Price et al. 2006, pp. 437-
439; Price et al. 2012, p. 198), Maryland, and Virginia (Grant et al. 
2009, pp. 1,372-1,375). In central Texas, Bowles et al. (2006, p. 117) 
found lower Jollyville Plateau salamander densities in tributaries with 
developed watersheds as compared to tributaries with undeveloped 
watersheds. Developed tributaries also had higher concentrations of 
chloride, magnesium, nitrate-nitrogen, potassium, sodium, and sulfate 
(Bowles et al. 2006, p. 117). Several biologists have concluded that 
urbanization is one of the largest threats to the future survival of 
central Texas salamanders (Bowles et al. 2006, p. 119; Chippindale and 
Price 2005, pp. 196-197).
    Willson and Dorcas (2003, pp. 768-770) demonstrated that to assess 
the impact of urbanization on aquatic salamanders, it is important to 
examine development within the entire watershed as opposed to areas 
just adjacent to the stream. For example, urban development within the 
drainage areas of Austin blind and Jollyville Plateau salamander spring 
sites has included residential and commercial structures, golf courses, 
and the associated roads and utility pipelines (Cole 1995, p. 28; COA 
2001, pp. 10-12).
    Because detrimental effects due to urbanization are occurring to 
the salamanders' habitats now, and we expect those effects to increase 
in the future, we consider urbanization to be a threat to each of the 
species. We discuss below how each source of the stressors of 
urbanization causes threats to the Austin blind, Jollyville Plateau, 
Georgetown, and Salado salamanders' habitats. These sources of impacts 
from urbanization include impervious cover and stormwater runoff, land 
application contaminants, hazardous material spills, construction 
activities, and water quantity reduction.

Impervious Cover and Stormwater Runoff

    Impervious cover is any surface material, such as roads, rooftops, 
sidewalks, patios, paved surfaces, or compacted soil, that prevents 
water from filtering into the soil (Arnold and Gibbons 1996, p. 244). 
Once natural vegetation in a watershed is replaced with impervious 
cover, rainfall is converted to surface runoff instead of filtering 
through the ground (Schueler 1991, p. 114).
    As urbanization increases due to human population growth within the 
watersheds of salamander habitat, levels of impervious cover will rise. 
Various levels of impervious cover within watersheds have been cited as 
having detrimental effects to water quality within streams. The 
threshold of measurable degradation of stream habitat and loss of 
biotic integrity consistently occurs with 6 to 15 percent impervious 
cover in contributing watersheds (Bowles et al. 2006, p. 111; Miller et 
al. 2007, p. 74). A review of relevant literature by Schueler (1994, 
pp. 100-102) indicates that stream degradation occurs at impervious 
cover of 10 to 20 percent, a sharp drop in habitat quality is found at 
10 to 15 percent impervious cover, and watersheds above 15 percent are 
consistently classified as poor, relative to biological condition. 
Schueler (1994, p. 102) also concluded that even when water quality 
protection practices are widely applied, an impervious cover level of 
35 to 60 percent exceeds a threshold beyond which water quality 
conditions that existed before development occurred cannot be 
maintained.

[[Page 50775]]

    Increases in impervious cover resulting from urbanization cause 
measurable water quality degradation (Klein 1979, p. 959; Bannerman et 
al. 1993, pp. 251-254, 256-258; Center for Watershed Protection 2003, 
p. 91). Stressors from impervious cover have demonstrable impacts on 
biological communities within streams. Schueler (1994, p. 104) found 
that sites receiving runoff from high impervious cover drainage areas 
had sensitive aquatic macroinvertebrate species replaced by species 
more tolerant of pollution and hydrologic stress (high rate of changes 
in discharges over short periods of time). In an analysis of 43 North 
Carolina streams, Miller et al. (2007, pp. 78-79) found a strong 
negative relationship between impervious cover and the abundance of 
larval southern two-lined salamanders (Eurycea cirrigera). Impervious 
cover degrades salamander habitat in three ways: (1) Introducing and 
concentrating contaminants in stormwater runoff, (2) increasing 
sedimentation, and (3) altering the natural flow regime of streams.
Impervious Cover Analysis
    To calculate impervious cover within the watersheds occupied by the 
four central Texas salamander species, we used the Watershed Boundary 
Dataset (USGS 2012, p. 1) to delineate the watersheds where these 
species are known to occur along with the 2006 National Land Cover 
Dataset (MRLC 2012, p. 1). The Watershed Boundary Dataset is a 
nationally consistent watershed dataset developed by the U.S. 
Geological Survey (USGS) that is subdivided into 12-digit hydrologic 
unit codes, which are the smallest (or finest scale) of the hydrologic 
units available. Each of the 12-digit hydrologic unit codes represents 
part or all of a surface drainage basin or a combination of drainage 
basins, also referred to in the Watershed Boundary Dataset as 
``watersheds.'' The 2006 National Land Cover Dataset (the most recent 
of the national land cover datasets) was developed by the Multi-
Resolution Land Characteristics Consortium to provide 30-meter spatial 
resolution estimates for tree cover and impervious cover percentages 
within the contiguous United States.
    We identified 15 of the watersheds delineated within the Watershed 
Boundary Dataset as being occupied by one of the four central Texas 
salamander species. The Jollyville Plateau salamander occurs within six 
watersheds (Bull Creek, Cypress Creek, Lake Creek, South Brushy Creek, 
Town Lake, and Walnut Creek). The Austin blind salamander occurs within 
one watershed (Lake Austin). The Georgetown salamander occurs within 
six watersheds (Dry Berry Creek, Lake Georgetown, Lower Berry Creek, 
Lower South Fork San Gabriel River, Middle Fork San Gabriel River, and 
Smith Branch San Gabriel River). The Salado salamander occurs within 
two watersheds (Buttermilk Creek and Mustang Creek).
    An impervious cover value (0 to 100 percent) is assigned for each 
30-meter pixel within the 2006 National Land Cover Dataset. Using these 
values, we calculated the overall average value (percentage) for each 
watershed identified. We also identified three categories of impervious 
cover for each pixel: (1) 0 percent impervious cover (no impervious 
cover was identified within the 30-meter pixel), (2) 1 to 15 percent 
impervious cover (between 1 and 15 percent of the 30-meter pixel was 
identified as impervious cover), and (3) greater than 15 percent 
impervious cover (more than 15 percent of the 30-meter pixel was 
identified as impervious cover). For each watershed, we then calculated 
the percentage of pixels that fell into each of these three categories. 
These percentages are presented in Table 1.

                                       Table 1--Impervious Cover Estimates
----------------------------------------------------------------------------------------------------------------
                                                                      Categories of impervious        Average
   Salamander species (total                          Number of        cover (IC) percentage        impervious
    number of known sites)          Watershed        salamander   -------------------------------   cover (IC)
                                                        sites        0% IC    1-15% IC   >15% IC    percentage
----------------------------------------------------------------------------------------------------------------
Jollyville Plateau salamander   Bull Creek.......              64        61         14        25           12.00
 (92).
                                Cypress Creek....              11        79          9        12            5.72
                                Lake Creek.......               3        43         17        40           21.35
                                South Brushy                    9        58         17        24           12.52
                                 Creek.
                                Town Lake........               4        11         30        59           34.32
                                Walnut Creek.....               1        34         17        50           28.03
Austin blind salamander (3)...  Lake Austin......               3        54         24        24           11.58
Georgetown salamander (16)....  Dry Berry Creek..               2        92          7         1            0.59
                                Lake Georgetown..               6        88         11         2            0.76
                                Lower Berry Creek               2        73         10        17            3.03
                                Lower South Fork                1        84         11         6            2.77
                                 San Gabriel
                                 River.
                                Middle Fork San                 4        77         11        12            2.41
                                 Gabriel River.
                                Smith Branch San                1        61         20        19            9.60
                                 Gabriel River.
Salado salamander (7).........  Buttermilk Creek.               3        95          5         1            0.31
                                Mustang Creek....               4        92          7         2            0.91
----------------------------------------------------------------------------------------------------------------

    We also identified areas within each watershed that we knew to be 
managed as open space. Open space includes lands set aside for either 
low-use recreation or wildlife preserves. The protection of open space 
helps preserve the quality of water, which is an important component of 
salamander surface habitat. Thus, we considered the amount and location 
of managed open space, and the potential water quality benefits they 
provide to salamander surface habitat during our analysis of threats 
caused by impervious cover within each watershed.
    The six watersheds within the Jollyville Plateau salamander's range 
have overall average impervious cover estimates ranging from 
approximately 6 percent (Cypress Creek) to 34 percent (Town Lake). The 
majority (64) of the 92 known Jollyville Plateau salamander sites are 
located within the Bull Creek watershed, which has an overall average 
impervious cover estimate of 12 percent. When average impervious cover 
is between 10 and 15 percent within a watershed, sharp declines in 
aquatic habitat quality are likely to occur (Schueler 1994, pp. 100-
102).
    However, a substantial portion of the land area categorized as open 
space and protected as part of the Balcones

[[Page 50776]]

Canyonlands Preserve is located within the Bull Creek watershed. The 
Balcones Canyonlands Preserve is managed under the terms and conditions 
of a regional habitat conservation plan (HCP) (the Balcones Canyonlands 
Conservation Plan HCP) jointly held by the City of Austin and Travis 
County as mitigation lands issued under the authority of an Endangered 
Species Act section 10(a)(1)(B) permit for the protection of endangered 
birds and karst invertebrates. A number of cooperating partners own and 
manage lands dedicated to the Balcones Canyonlands Preserve, including 
several private landowners, the Lower Colorado River Authority, the 
Nature Conservancy of Texas, and the Travis Audubon Society. Although 
the permit that created the Balcones Canyonlands Preserve did not 
include the Jollyville Plateau salamander, the Balcones Canyonlands 
Preserve land management strategies help maintain water quality within 
salamander habitats on lands within the preserve. Nonetheless, the City 
of Austin has reported significant declines in Jollyville Plateau 
salamander abundance at one of their Jollyville Plateau salamander 
monitoring sites within Bull Creek (O'Donnell et al. 2006, p. 45), even 
though our analysis found that 61 percent of the land within this 
watershed has 0 percent impervious cover. The location of this 
monitoring site is within a large preserved tract. However, the 
headwaters of this drainage are outside the preserve, and the 
development in this area increased sedimentation downstream and 
impacted salamander habitat in the preserved tract.
    The Cypress Creek watershed is the least developed of all of the 
watersheds within the Jollyville Plateau salamander's range, and much 
of it is extensively covered by lands that are managed as open space. 
The vast majority of this open space is part of the Balcones 
Canyonlands Preserve. There are 11 spring sites known to be occupied by 
the Jollyville Plateau salamander within this watershed. Seven of these 
sites are located directly within or downstream from areas dominated by 
impervious surfaces. The 2006 National Land Cover Dataset data 
indicated that 12 percent of the 30-m pixels in the Cypress Creek 
watershed have impervious cover of 15 percent or more and 9 percent of 
the 30-m pixels have impervious cover between 1 and 15 percent.
    The other watersheds within the Jollyville Plateau salamander's 
range have impervious cover levels that may lead to water quality 
declines within salamander surface habitat (Schueler 1994, pp. 100-
102). Nine sites known to be occupied by Jollyville Plateau salamanders 
are located within the South Brushy Creek watershed, which has an 
overall average impervious cover estimate of 13 percent and very little 
managed open space. Again, when average impervious cover is between 10 
and 15 percent, sharp declines in aquatic habitat quality are likely to 
occur (Schueler 1994, pp. 100-102).
    The Lake Creek watershed with three known salamander locations and 
the Walnut Creek watershed with one known salamander location are 
estimated to have 21 percent and 28 percent impervious cover, 
respectively. The Lake Creek watershed has two tracts (143 ac (58 ha) 
and 95 ac (38 ha)) of managed open space along with two smaller 
preserve areas and several municipal parks. Given their small size in 
relation to the size of the watershed, it is unknown if these areas 
provide any water quality benefits for salamander surface habitat. The 
single Jollyville Plateau salamander location within the Walnut Creek 
watershed is located on a 53-ac (21-ha) park that is situated directly 
adjacent to a residential development. There are two small (14 ac (6 
ha) and 67 ac (27 ha)) municipal parks located upstream from this site. 
However, the 2006 National Land Cover Dataset data indicated that 50 
percent of the 30-m pixels in the Walnut Creek watershed have 
impervious cover of 15 percent or more and 17 percent of the 30-m 
pixels have impervious cover between 1 and 15 percent. Because this 
watershed is extensively covered by impervious surfaces, it is unlikely 
that these managed open spaces provide adequate water quality for the 
Jollyville Plateau salamander. Salamander counts at the Walnut Creek 
location have been low. Although surveys are conducted four times a 
year, no salamanders were observed from 2006 to 2009, and only six 
individuals were observed in 2010 (Bendik 2011a, p. 13).
    The Town Lake watershed is the most developed of all of the 
watersheds within the Jollyville Plateau salamander's range. Four 
Jollyville Plateau salamander sites are located within the Town Lake 
watershed, which has an estimated 30 percent of its 30-m pixels within 
the 1 to 15 percent impervious cover category and 59 percent of its 30-
m pixels within the greater than 15 percent impervious cover category. 
We could not identify any parcels of land that are managed as open 
space within the Town Lake watershed.
    The Austin blind salamander occurs within only one of the 
watersheds (Lake Austin) delineated within the Watershed Boundary 
Dataset. The Lake Austin watershed was estimated to have an overall 
average impervious cover estimate of 12 percent. Although each of the 
three spring sites where this species is known to occur are located 
within a park managed by the City of Austin, the water quality within 
the salamander's habitat can be influenced by development throughout 
the watershed. The impervious cover within the Lake Austin watershed, 
which is an indicator of development intensity within the area, is 
within the range that can lead to water quality declines in aquatic 
habitats (Schueler 1994, pp. 100-102). Some Balcones Canyonlands 
Preserve lands are located within the Lake Austin watershed, which 
likely contribute some water quality benefits to surface flow. However, 
the Austin blind salamander is, in large part, a subterranean species. 
Therefore, water quality within this species' habitat can be influenced 
by land use throughout the recharge zone of the Barton Springs Segment 
of the Edwards Aquifer.
    The Lower Colorado River Authority (LCRA 2002, pp. 3-54--3-55) 
conducted a water supply study of the recharge and contributing zone 
areas within the Barton Springs Segment of the Edwards Aquifer that 
examined the amount of impervious cover within the local area. The 
eight watersheds within the area had a range of impervious cover from 3 
percent to 29 percent in 2000. The projected impervious cover limits 
for the same eight watersheds in 2025 ranged from 5 percent to 32 
percent (LCRA 2002, pp. 4-12--4-13). The two watersheds, Williamson 
Creek and Sunset Valley Creek (a tributary to Williamson Creek), with 
the highest percentage of impervious cover (16 and 29 percent, 
respectively) are also the second and third closest to Barton Springs 
(LCRA 2002, pp. 4-12--4-13).
    The six watersheds within the Georgetown salamander's range have 
overall average impervious cover estimates ranging from 0.59 percent 
(Dry Berry Creek) to about 10 percent (Smith Branch San Gabriel River). 
The overall average impervious cover estimates for each of the six 
watersheds are below the levels that have been shown to lead to sharp 
water quality declines in aquatic habitats (Schueler 1994, pp. 100-
102). Two (Cobbs Spring and Cobbs Spring Well) of the 16 sites known to 
be occupied by the Georgetown salamander occur in the headwaters of the 
Dry Berry Creek watershed, which has an overall average impervious 
cover estimate of 0.59 percent.
    Six spring sites known to be occupied by Georgetown salamander are 
located within the Lake Georgetown watershed.

[[Page 50777]]

This watershed also has one of the least overall average impervious 
cover estimates (0.76 percent) of the six watersheds within the 
Georgetown salamander's range. These six sites, along with three of the 
four spring sites known to be occupied by the Georgetown salamander in 
the Middle Fork San Gabriel River watershed (with an overall average 
impervious cover estimate of about 2 percent) and the only known 
Georgetown salamander site within the Lower South Fork San Gabriel 
River watershed (with an overall average impervious cover estimate of 
about 3 percent), are located upstream from the urbanized areas 
associated with the City of Georgetown. Therefore, these sites are 
likely not as affected by water quality degradation currently as those 
spring sites occupied by the Georgetown salamander within the highly 
urbanized areas of the City of Georgetown.
    We identified two tracts of land managed specifically as open space 
within the Georgetown salamander's range. Williamson County manages a 
64-ac (26-ha) conservation easement at Cobbs Cavern and owns the 145-ac 
(59-ha) Twin Springs Preserve. The Twin Springs preserve contains one 
Georgetown salamander site. While the Cobbs Cavern conservation 
easement does not include the Cobbs Spring or Cobbs well site, it does 
contain land in the watershed for these sites. Despite the protection 
of these two tracts, water quality at these sites can be influenced by 
activities occurring throughout the recharge zone. Without more managed 
open space within this species' range, it is unlikely that water 
quality within the Georgetown salamander's surface habitat will be 
protected as development continues in these watersheds into the future.
    Four of the 16 sites known to be occupied by the Georgetown 
salamander are located in areas identified as having impervious cover 
estimates (either in the 1 to 15 percent impervious cover category or 
the greater than 15 percent impervious cover category) within the range 
that can lead to water quality declines (10 to 15 percent) or poor 
water quality relative to biological condition (greater than 15 
percent) in aquatic habitats (Schueler 1994, pp. 100-102). These 
include one site in the Middle Fork San Gabriel River watershed, the 
only occupied site within the Smith Branch San Gabriel River watershed 
(with an overall average impervious cover estimate of about 10 
percent), and the two occupied sites within the Lower Berry Creek 
watershed (with an overall average impervious cover estimate of about 3 
percent). Although the overall average impervious cover estimate within 
Lower Berry Creek watershed is below the level that has been shown to 
lead to water quality declines in aquatic habitats (Schueler 1994, pp. 
100-102), 17 percent of the watershed has greater than 15 percent 
impervious cover. These two Georgetown salamander sites are located in 
the most developed area of this watershed. As such, these sites are 
vulnerable to water quality degradation caused by pollutants associated 
with highly urbanized areas.
    The Salado salamander occurs within two of the watersheds 
delineated within the Watershed Boundary Dataset. Buttermilk Creek and 
Mustang Creek watersheds have overall average impervious cover 
estimates of 0.31 percent and 0.91 percent, respectively. Although 
these impervious cover levels are well below that which are likely to 
lead to water quality declines in aquatic habitats (Schueler 1994, pp. 
100-102), three of the seven springs sites known to be occupied by the 
Salado salamander are directly within urbanized habitats in the Mustang 
Creek watershed (within the Village of Salado), and therefore, may be 
more susceptible to spills of hazardous materials and pollutants from 
roads that are close to locations where salamanders are known to occur.
    Four spring sites known to be occupied by Salado salamanders are 
upstream from the urbanized areas associated with the Village of 
Salado. Three of these spring sites are located within the Buttermilk 
Creek watershed on an approximately 8,126-ac (3,288-ha) ranch that is 
privately owned and almost entirely undeveloped. Another spring site 
known to be occupied by the Salado salamander within the Mustang Creek 
watershed is located on another privately owned and almost entirely 
undeveloped ranch that is approximately 827 ac (335 ha) in size. Both 
ranches are located upstream of the impervious cover areas associated 
with the Village of Salado and entirely within the recharge zone of the 
Northern Segment of the Edwards Aquifer. Although impervious cover is 
not currently a threat to these upstream sites, a significant portion 
of the recharge zone extends to areas off of these properties and 
spring water quality can be impacted by activities occurring some 
distance away.
    We could not identify any large tracts of lands managed 
specifically as open space within the Salado salamander's range, 
particularly upstream of sites where this species is known to occur. In 
addition, there are no agreements in place to preserve or manage the 
above-mentioned properties for the benefit of the Salado salamander or 
its surface habitat. Without these, it is unlikely that water quality 
within the Salado salamander's surface habitat will be protected if 
development occurs in these watersheds in the future.
    Although the data for this level of the impervious cover analysis 
were derived using the finest scale hydrologic units readily available 
in the Watershed Boundary Dataset, they offer no reference to the 
location of salamander-occupied spring sites in relation to the 
location of impervious cover within the watersheds. Therefore, 
impervious cover occurring within each watershed may not necessarily be 
an indicator of how much impervious cover is impacting water quality 
within known salamander sites because this analysis does not take into 
account whether the salamander sites are found upstream or downstream 
of impervious surfaces associated with developed areas. Moreover, 
because the most recent impervious cover estimates available within the 
National Land Cover Dataset were provided from 2006 data, more 
impervious cover could be present within the watersheds than are 
indicated in our analysis. By mapping the spring sites where 
salamanders are known to occur over the 2006 National Land Cover 
Dataset impervious cover data layer, we can generally discuss which 
sites may currently be affected by water quality degradation due to 
their location within the three impervious cover categories mentioned 
above and identified in Table 1.
    To provide a general indication of how much impervious cover may be 
influencing surface water quality at individual salamander sites, we 
used 2010 aerial photos to visually estimate the amount of impervious 
cover upstream of each site known to be occupied by the Jollyville 
Plateau, Georgetown, or Salado salamander. By visually examining the 
aerial photos from 2010, we classified the areas within each tributary 
watershed upstream from each known salamander site into one of four 
categories (that represent approximations of impervious cover levels). 
We defined these categories as follows: (1) None (a tributary watershed 
with no visible impervious cover), (2) low (a tributary watershed with 
what appeared to be less than 10 percent impervious cover), (3) 
moderate (a tributary watershed with what appeared to be impervious 
cover between 10 and 30 percent), and (4) high (a tributary watershed 
with what appeared to be greater than 30 percent impervious cover). A 
summary of the number of salamander sites for each of these three 
species found to be within

[[Page 50778]]

the impervious cover categories is provided below (Table 2).

                   Table 2--Impervious Cover Estimates Upstream of Known Salamander Locations
----------------------------------------------------------------------------------------------------------------
                                     Number of             Number of sites with impervious cover levels
       Salamander species           salamander   ---------------------------------------------------------------
                                       sites           None             Low          Moderate          High
----------------------------------------------------------------------------------------------------------------
Jollyville Plateau salamander...              92              17               6              21              48
Georgetown salamander...........              16               4               9               2               1
Salado Salamander...............               7               2               4               0               1
----------------------------------------------------------------------------------------------------------------

    The Austin blind salamander was not considered in the analysis of 
impervious cover upstream of its known sites, as it primarily occurs 
below the surface and is more likely to be impacted by water quality 
changes due to impervious cover throughout the Edward Aquifer's 
recharge zone. Using the 2006 National Land Cover Database, we 
determined that the recharge zone of the Barton Springs Segment of the 
Edwards Aquifer had an overall average impervious cover level of 5.87 
percent. However, at least 12 percent of the recharge zone has greater 
than 15 percent impervious cover.
Contaminants in Stormwater Runoff
    Urban environments are host to a variety of human activities that 
generate many types of point source (``end of pipe'') and non-point 
source (coming from many diffuse sources) contaminants. These sources 
of contaminants, when combined, often degrade nearby waterways and 
aquatic resources within the watershed. Urban contaminants commonly 
detected in stormwater include elevated levels of suspended solids, 
nutrients, trace metals, pesticides, and coliform bacteria. Similarly, 
various industrial and municipal activities result in the discharge of 
treated wastewater or unintentional release of industrial contaminants 
as point source pollution.
    Stormwater runoff carries these contaminants into stream systems 
(Bannerman et al. 1993, pp. 251-254, 256-258; Schueler 1994, p. 102; 
Barrett and Charbeneau 1996, p. 87; Center for Watershed Protection 
2003, p. 91). Amphibians, especially their eggs and larvae (which are 
usually restricted to a small area within an aquatic environment), are 
sensitive to many different aquatic pollutants (Harfenist et al. 1989, 
pp. 4-57). Contaminants found in aquatic environments, even at 
sublethal concentrations, may interfere with a salamander's ability to 
develop, grow, or reproduce (Burton and Ingersoll 1994, pp. 120, 125). 
Central Texas spring salamanders are particularly vulnerable to 
contaminants, because they have evolved under very stable environmental 
conditions, remain aquatic throughout their entire life cycle, have 
highly permeable skin, have severely restricted ranges, and cannot 
escape contaminants in their environment (Turner and O'Donnell 2004, p. 
5). In addition, macroinvertebrates, such as small freshwater 
crustaceans, that aquatic salamanders feed on are especially sensitive 
to water pollution (Phipps et al. 1995, p. 282; Miller et al. 2007, p. 
74). Studies in the Bull Creek watershed in Austin, Texas, found a loss 
of some sensitive macroinvertebrate species, potentially due to 
contaminants of nutrient enrichment and sediment accumulation (COA 
2001, p. 15; COA 2010a, p. 16).
    Both nationally and locally, consistent relationships between 
impervious cover and water quality degradation through contaminant 
loading have been documented. In a study of contaminant loads from 
various land use areas in Austin, stormwater runoff loads were found to 
increase with increasing impervious cover (COA 1990, pp. 12-14). This 
study also found that contaminant loading rates of the more urbanized 
watersheds were higher than those of the small suburban watersheds. 
Soeur et al. (1995, p. 565) determined that stormwater contaminant 
loading positively correlated with development intensity in Austin. In 
a study of 38 small watersheds in the Austin area, 7 different 
contaminants were found to be positively correlated with impervious 
cover (COA 2006, p. 35). Using stream data from 1958 to 2007 at 24 
Austin-area sites, Glick et al. (2009, p. 9) found that the City of 
Austin's water quality index had a strong negative correlation with 
impervious cover.
    Polycyclic aromatic hydrocarbons (PAHs) are a common form of 
aquatic contaminants in urbanized areas that could potentially affect 
salamanders, their habitat, or their prey. This form of pollution can 
originate from petroleum products, such as oil or grease, or from 
atmospheric deposition as a byproduct of combustion (for example, 
vehicular combustion). These pollutants accumulate over time on 
impervious cover, contaminating water supplies through urban and 
highway runoff (Van Metre et al. 2000, p. 4,067; Albers 2003, pp. 345-
346). The main source of PAH loading in Austin-area streams is parking 
lots with coal tar emulsion sealant, even though this type of lot only 
covers 1 to 2 percent of the watersheds (Mahler et al. 2005, p. 5565). 
A recent analysis of the rate of wear on coal tar lots revealed that 
the sealcoat wears off relatively quickly and contributes more to PAH 
loading than previously thought (Scoggins et al. 2009, p. 4914).
    Petroleum and petroleum byproducts can adversely affect living 
organisms by causing direct toxic action, altering water chemistry, 
reducing light, and decreasing food availability (Albers 2003, p. 349). 
Exposure to PAHs at levels found within the Jollyville Plateau 
salamander's range can cause impaired reproduction, reduced growth and 
development, and tumors or cancer in species of amphibians, reptiles, 
and other organisms (Albers 2003, p. 354). Coal tar pavement sealant 
slowed hatching, growth, and development of a frog (Xenopus laevis) in 
a laboratory setting (Bryer et al. 2006, pp. 244-245). High 
concentrations of PAHs from coal tar sealant negatively affected the 
righting ability (amount of time needed to flip over after being placed 
on back) of adult eastern newts (Notophthalmus viridescens) and may 
have also damaged the newt's liver (Sparling et al. 2009, pp. 18-20). 
For juvenile spotted salamanders (Ambystoma maculatum), PAHs reduced 
growth in the lab (Sparling et al. 2009, p. 28). In a lab study using 
the same coal tar sealant once used by the City of Austin, Bommarito et 
al. (2010, pp. 1151-1152) found that spotted salamanders displayed 
slower growth rates and diminished swimming ability when exposed to 
PAHs. PAHs are also known to cause death, reduced survival, altered 
physiological function, inhibited reproduction, and changes in

[[Page 50779]]

community composition of freshwater invertebrates (Albers 2003, p. 
352).
    Limited sampling by the City of Austin has detected PAHs at 
concentrations of concern at multiple sites within the range of the 
Jollyville Plateau salamander. Most notable were the elevated levels of 
nine different PAH compounds at the Spicewood Springs site in the Shoal 
Creek drainage area (O'Donnell et al. 2005, pp. 16-17). This is also 
one of the sites where salamanders have shown a significant decline in 
abundance during the City of Austin's long-term monitoring studies 
(O'Donnell et al. 2006, p. 47). Another study found several PAH 
compounds in seven Austin-area streams, including Barton, Bull, and 
Walnut Creeks, downstream of coal tar sealant parking lots (Scoggins et 
al. 2007, p. 697). Sites with high concentrations of PAHs (located in 
Barton and Walnut Creeks) had fewer macroinvertebrate species and lower 
macroinvertebrate density (Scoggins et al. 2007, p. 700). This form of 
contamination has also been detected at Barton Springs, which is the 
Austin blind salamander's habitat (COA 1997, p. 10). Because PAHs can 
adversely affect salamanders, PAHs have been found in the range of the 
species, and we expect an increase of this contaminant in the future in 
conjunction with the increase of urbanization, we consider 
contamination from PAHs to be a threat to the continued existence of 
all four central Texas salamanders now and in the future.
    Conductivity is a measure of the ability of water to carry an 
electrical current and can be used to approximate the concentration of 
dissolved inorganic solids in water that can alter the internal water 
balance in aquatic organisms, affecting the four central Texas 
salamanders' survival. As ion concentrations such as chlorides, sodium, 
sulfates, and nitrates rise, conductivity will increase. These 
compounds are the chemical products, or byproducts, of many common 
pollutants that originate from urban environments (Menzer and Nelson 
1980, p. 633), which are often transported to streams via stormwater 
runoff from impervious cover. Measurements by the City of Austin 
between 1997 and 2006 found that conductivity averaged between 550 and 
650 microsiemens per centimeter ([mu]S cm-1) at rural 
springs with low or no development and averaged between 900 and 1000 
[mu]S cm-1 at monitoring sites in watersheds with urban 
development (O'Donnell et al. 2006, p. 37). The City of Austin also 
found increasing ions with increasing impervious cover at four 
Jollyville Plateau salamander sites (Herrington et al. 2007, p. 13). 
These results indicate that developed watersheds contribute to higher 
levels of water contaminants in salamander habitats.
    High conductivity has been associated with declining salamander 
abundance. For example, three of the four sites with statistically 
significant declining Jollyville Plateau salamander abundance from 1997 
to 2006 are cited as having high conductivity readings (O'Donnell et 
al. 2006, p. 37). Similar correlations were shown in studies comparing 
developed and undeveloped sites from 1996 to 1998 (Bowles et al. 2006, 
pp. 117-118). This analysis found significantly lower numbers of 
salamanders and significantly higher measures of specific conductance 
at developed sites as compared to undeveloped sites (Bowles et al. 
2006, pp. 117-118). Tributary 5 of Bull Creek has had an increase in 
conductivity, chloride, and sodium and a decrease in invertebrate 
diversity from 1996 to 2008 (COA 2010a, p. 16). Only one Jollyville 
Plateau salamander has been observed here from 2009 to 2010 in 
quarterly surveys (Bendik 2011a, p. 16). Poor water quality, as 
measured by high specific conductance and elevated levels of ion 
concentrations, is cited as one of the likely factors leading to 
statistically significant declines in salamander abundance at the City 
of Austin's long-term monitoring sites (O'Donnell et al. 2006, p. 46).
    In an analysis performed by the City of Austin (Turner 2005a, p. 
6), significant changes over time were reported for several chemical 
constituents and physical parameters in Barton Springs Pool, which 
could be attributed to impacts from watershed urbanization. 
Conductivity, turbidity, sulfates, and total organic carbon have 
increased while the concentration of dissolved oxygen has decreased 
(Turner 2005a, pp. 8-17). The significance and presence of trends in 
other pollutants were variable depending on flow conditions (baseflow 
vs. stormflow, recharge vs. non-recharge) (Turner 2005a, p. 20). A 
similar analysis by Herrington and Hiers (2010, p. 2) examined water 
quality at Barton Springs Pool and other Barton Springs outlets where 
Austin blind salamanders are found (Sunken Gardens and Eliza Springs) 
over a general period of the mid-1990s to the summer of 2009. 
Herrington and Hiers (2010, pp. 41-42) found that dissolved oxygen 
decreased over time in the Barton Springs Pool, while conductivity and 
nitrogen increased. However, this decline in water quality was not seen 
in Sunken Gardens Spring or Elisa Spring (Herrington 2010, p. 42). A 
separate analysis found that ions such as chloride and sulfate 
increased in Barton Creek despite the enactment of city-wide water 
quality control ordinances (Turner 2007, p. 7). Overall, these studies 
indicate a long-term trend of water quality degradation at Barton 
Springs over a 34-year period (1975 to 2009).
    In summary, there are many different types of contaminants found in 
stormwater runoff that can have detrimental effects on the four central 
Texas salamanders. Impervious cover increases the transport of 
contaminants common in urban environments, and we expect this 
detrimental effect to increase in the future with increased 
urbanization. Therefore, the current existence and future increase of 
contaminants in stormwater runoff is a significant threat to all four 
central Texas salamanders' surface and subsurface habitats throughout 
their ranges. However, due to the relatively low levels of impervious 
cover in its range, the Salado salamander is currently, and anticipated 
to be, less affected.
Sedimentation from Stormwater Runoff
    Elevated mobilization of sediment (mixture of silt, sand, clay, and 
organic debris) occurs as a result of increased velocity of water 
running off impervious surfaces (Schram 1995, p. 88; Arnold and Gibbons 
1996, pp. 244-245). Increased rates of stormwater runoff cause 
increased erosion through scouring in headwater areas and sediment 
deposition in downstream channels (Booth 1991, pp. 93, 102-105; Schram 
1995, p. 88). Waterways are adversely affected in urban areas, where 
impervious cover rates are high, by sediment loads that are washed into 
streams or aquifers during storm events. Sediments are either deposited 
into layers or become suspended in the water column (Ford and Williams 
1989, p. 537; Mahler and Lynch 1999, p. 177). Sediment derived from 
soil erosion has been cited as the greatest single source of pollution 
of surface waters by volume (Menzer and Nelson 1980, p. 632).
    Excessive sediment from stormwater runoff is a threat to 
salamanders because it can cover habitat, cover substrates, and lead to 
declines in vegetative abundance and diversity (Geismar 2005, p. 2). 
Sediments suspended in water can clog gill structures, which impairs 
breathing of aquatic organisms, and can reduce their ability to avoid 
predators or locate food sources due to decreased visibility (Schueler 
1987, p. 1.5). Excessive deposition of sediment in streams can 
physically reduce the

[[Page 50780]]

amount of available habitat and protective cover for aquatic organisms, 
by filling the interstitial spaces of gravel and rocks. As an example, 
a California study found that densities of two salamander species were 
significantly lower in streams that experienced a large infusion of 
sediment from road construction after a storm event (Welsh and Ollivier 
1998, pp. 1,118-1,132). The vulnerability of the salamander species in 
this California study was attributed to their reliance on interstitial 
spaces in the streambed habitats (Welsh and Ollivier 1998, p. 1,128). 
We consider increased sedimentation from impervious cover to be a 
threat to all four central Texas salamanders, because it fills 
interstitial spaces, eliminates resting places, and reduces habitat of 
its prey base (small aquatic invertebrates) (O'Donnell et al. 2006, p. 
34).
    Also, sediments eroded from contaminated soil surfaces can 
concentrate and transport contaminants (Mahler and Lynch 1999, p. 165). 
The four central Texas salamander species and their prey species are 
directly exposed to sediment-borne contaminants present within the 
aquifer and discharging through the spring outlets. For example, in 
addition to sediment, trace metals such as arsenic, cadmium, copper, 
lead, nickel, and zinc were found in Barton Springs in the early 1990s 
(COA 1997, pp. 229, 231-232). Contaminants may cause adverse effects to 
the salamander and its prey species including reduced growth and 
weight, abnormal behavior, morphological and developmental aberrations, 
and decreased reproductive activity (Albers 2003, p. 354).
    Excess sedimentation may have contributed to declines in Jollyville 
Plateau salamander populations in the past. Monitoring by the City of 
Austin found that, as sediment deposition increased at several sites, 
salamander abundances significantly decreased (COA 2001, pp. 101, 126). 
Additionally, the City of Austin found that sediment deposition rates 
have increased significantly along one of the long-term monitoring 
sites (Bull Creek Tributary 5) as a result of construction activities 
upstream (O'Donnell et al. 2006, p. 34). This site has had significant 
declines in salamander abundance, based on 10 years of monitoring, and 
the City of Austin attributes this decline to the increases in 
sedimentation (O'Donnell et al. 2006, pp. 34-35). The location of this 
monitoring site is within a large preserved tract. However, the 
headwaters of this drainage are outside the preserve and the 
development in this area increased sedimentation downstream and 
impacted salamander habitat in the preserved tract.
    Direct evidence of the effects of sedimentation on the Austin 
blind, Georgetown, and Salado salamanders is lacking, primarily due to 
limited studies on those species. However, analogies can be drawn from 
data on similar species, such as the Jollyville Plateau and Barton 
Springs salamanders. Barton Spring salamander population numbers are 
adversely affected by high turbidity and sedimentation (COA 1997, p. 
13). Sediments discharge through Barton Springs, even during baseflow 
conditions (not related to a storm event) (Geismar 2005, p. 12). Storms 
can increase sedimentation rates substantially (Geismar 2005, p. 12). 
Areas in the immediate vicinity of the spring outflows lack sediment, 
but the remaining bedrock is sometimes covered with a layer of sediment 
several inches thick (Geismar 2005, p. 5). Sedimentation is a direct 
threat for the Austin blind salamander because its habitat in Barton 
Springs would fill with sediment if it were not for regular maintenance 
and removal (Geismar 2005, p. 12). Further development in the Barton 
Creek watershed will most likely be associated with diminished water 
clarity and a reduction in biodiversity of flora (COA 1997, p. 7). 
Likewise, development within the watersheds of Georgetown and Salado 
salamander sites will increase sedimentation and degrade water quality 
in salamander habitat. Therefore, because salamander population numbers 
are adversely affected by sedimentation covering habitat, filling in 
substrates, and transporting contaminants in both surface and 
subsurface habitats, we consider sedimentation and its resulting 
effects to be an ongoing, significant threat to all four central Texas 
salamanders' surface and subsurface habitats now and in the future. 
However, we consider the Salado salamander to salamander to be less 
affected by this threat than the other three species, due to the 
relatively low levels of impervious cover in its range.
Changes in Flow Regime Due to Impervious Cover
    Impervious cover in a stream's watershed causes streamflow to shift 
from predominately baseflow, which is derived from natural filtration 
processes and discharges from local groundwater supplies, to 
predominately stormwater runoff. With increasing stormwater runoff, the 
amount of baseflow available to sustain water supplies during drought 
cycles is diminished and the frequency and severity of flooding 
increases. The increased quantity and velocity of runoff increases 
erosion and streambank destabilization, which in turn leads to 
increased sediment loadings, channel widening, and detrimental changes 
in the morphology and aquatic ecology of the affected stream system 
(Hammer 1972, pp. 1535-1536, 1540; Booth 1990, pp. 407-409, 412-414; 
Booth and Reinelt 1993, pp. 548-550; Schueler 1994, pp. 106-108; 
Pizzuto et al. 2000, p. 82; Center for Watershed Protection 2003, pp. 
41-48).
    The changes in flow regime due to impervious cover can have a 
direct impact on salamander populations. For example, Barrett et al. 
(2010, pp. 2002-2003) recently observed that the density of aquatic 
southern two-lined salamanders declined more drastically in streams 
with urbanized watersheds compared to streams with forested or pastured 
watersheds. A statistical analysis indicated that this decline in urban 
streams was due to an increase in flooding frequency from stormwater 
runoff. Barrett et al. (2010, p. 2003) also used artificial stream 
experiments to demonstrate that salamanders were flushed downstream at 
significantly lower velocities when the substrate was sand-based, as 
compared to gravel, pebble, or cobble-based. Sand-based substrates are 
common to urban streams due to high sedimentation rates (see 
``Sedimentation from Stormwater Runoff'' section, above). The combined 
effects of increased sand-based substrates due to high sedimentation 
rates, and increased flow velocities from impervious cover, result in 
effectively removing salamanders from their habitat.
    Extreme flood events have occurred in all four salamander species' 
surface habitats (Pierce 2011a, p. 10; TPWD 2011a, p. 6; Turner 2009, 
p. 11; O'Donnell et al. 2005, p. 15). It is reasonable to assume that 
impervious cover due to urbanization in the salamanders' watershed will 
continue to cause streamflow to shift from predominately baseflow to 
predominately stormwater runoff. For example, an examination of 24 
stream sites in the Austin area revealed that increasing impervious 
cover in the watersheds resulted in decreased base flow, increased 
high-flow events of shorter duration, and more rapid rises and falls of 
the stream flow (Glick et al. 2009, p. 9). In addition, increases in 
impervious cover within the Walnut Creek watershed (Jollyville Plateau 
salamander habitat) have probably caused a shift to more rapid rises 
and falls of the stream flow (Herrington 2010, p. 11). Because of the 
detrimental effects previously discussed in association with increased 
stormwater

[[Page 50781]]

runoff, and because the amount of baseflow available to sustain water 
supplies during drought cycles is diminished, we consider changes in 
flow regime due to impervious cover to be an ongoing threat to all four 
central Texas salamanders' surface habitats now and in the future. 
Because it only affects surface habitat, this threat is of moderate 
significance to the Austin blind, Jollyville Plateau, and Georgetown 
salamanders. We consider this threat to be of low significance for the 
Salado salamander due to the relatively low levels of impervious cover 
in its range.
Conclusion of Impervious Cover and Stormwater Runoff
    In summary, impervious cover contributes to the degradation of 
surface and subsurface salamander habitat by transporting contaminants 
and sediments to the Edwards Aquifer. Impervious cover within the 
watersheds of the salamanders also leads to changes in streamflow 
regime that degrades surface salamander habitat. The Austin blind, 
Jollyville Plateau, and Georgetown salamanders all have levels of 
impervious cover in their ranges that may be causing declines in water 
quality. Impervious cover levels are relatively low in the range of the 
Salado salamander. However, growing human populations and the 
associated increase in urbanization indicate that impervious cover 
levels will continue to rise within the ranges of all four central 
Texas salamanders. Therefore, we consider impervious cover and 
stormwater runoff to be sources of stressors, such as contamination, 
sedimentation, and changes in streamwater's flow regime, that 
contribute to the overall risk of extinction for all four salamander 
species.

Land Application Contaminants

    Excessive land application contaminants, such as nutrient and 
pesticide input to watershed drainages, are other forms of pollution 
that occur in highly urbanized areas. In comparison to nonkarstic 
aquifer systems, the Edwards Aquifer is more vulnerable to the effects 
of contamination due to: (1) A large number of conduits that offer no 
filtering capacity, (2) high groundwater flow velocities, and (3) the 
relatively short amount of time that water is inside the aquifer system 
(Ford and Williams 1989, pp. 518-519).
    Even at low concentrations, land application contaminants, such as 
nutrients and pesticides, can disrupt aquatic life. Some of these 
chemicals may accumulate in the fatty tissue of aquatic organisms and 
impair their ability to reproduce, escape predation, maintain metabolic 
processes, and survive (Ross 2011, p. 6). In addition, 
macroinvertebrates, such as small freshwater crustaceans on which these 
four central Texas salamander species feed are especially sensitive to 
water pollution (Phipps et al. 1995, p. 282; Miller et al. 2007, p. 
74).

Nutrients

    Nutrient input (such as phosphorus and nitrogen) to watershed 
drainages, which often results in abnormally high organic growth in 
aquatic ecosystems, can originate from multiple sources, such as human 
and animal wastes, industrial pollutants, and fertilizers (from lawns, 
golf courses, or croplands) (Garner and Mahler 2007, p. 29). As the 
human population grows and subsequent urbanization occurs within the 
ranges of these four central Texas salamander species, they likely 
become more susceptible to the effects of excessive nutrients within 
their habitats. To illustrate, an estimated 102,262 domestic dogs and 
cats (pet waste is a potential source of excessive nutrients) were 
known to occur within the Barton Springs Segment of the Edwards Aquifer 
in 2010 (Herrington et al. 2010, p. 15). Their distributions were 
correlated with human population density (Herrington et al. 2010, p. 
15).
    Various residential properties and golf courses are known to use 
pesticides, herbicides, and fertilizers to maintain turfgrass within 
watersheds where Jollyville Plateau salamander populations are known to 
occur (COA 2003, pp. 1-7). Analysis of water quality constituents 
conducted by the City of Austin (1997, pp. 8-9) showed significant 
differences in nitrate, ammonia, total dissolved solids, total 
suspended solids, and turbidity concentrations between watersheds 
dominanted by golf courses, residential land, and rural land. Golf 
course tributaries were found to have higher concentrations of these 
constituents than residential tributaries, and both golf course and 
residential tributaries had substantially higher concentrations for 
these five constituents than rural tributaries (COA 1997, pp. 8-9).
    Residential irrigation of wastewater effluent has led to excessive 
nutrient input into the recharge zone of the Barton Springs Segment of 
the Edwards Aquifer (Ross 2011, pp. 11-18). Wastewater effluent permits 
do not require treatment to remove metals, pharmaceutical chemicals, or 
the wide range of chemicals found in body care products, soaps, 
detergents, pesticides, or other cleaning products (Ross 2011, p. 6). 
These chemicals remaining in treated wastewater effluent can enter 
streams and the aquifer and alter water quality within salamander 
habitat.
    Excessive nutrient input into aquatic systems can increase plant 
growth, which pulls more oxygen out of the water when the dead plant 
matter decomposes, resulting in less oxygen being available in the 
water for salamanders to breathe (Schueler 1987, pp. 1.5-1.6; Ross 
2011, p. 7). A reduction in dissolved oxygen concentrations could not 
only affect respiration in salamander species, but also lead to 
decreased metabolic functioning and growth in juveniles (Woods et al. 
2010, p. 544), or death (Ross 2011, p. 6). Excessive plant material can 
also reduce stream velocities and increase sediment deposition (Ross 
2011, p. 7). When the interstitial spaces become compacted or filled 
with fine sediment, the amount of available foraging habitat and 
protective cover is reduced (Welsh and Ollivier 1998, p. 1,128). 
Studies in the Bull Creek watershed found a loss of some sensitive 
macroinvertebrate species, potentially due to nutrient enrichment and 
sediment accumulation (COA 2001b, p. 15).
    Poor water quality, particularly elevated nitrates, may also be a 
cause of morphological deformities in individual Jollyville Plateau 
salamanders. The City of Austin has documented very high levels of 
nitrates (averaging over 6 milligrams per liter (mg L\-1\) with some 
samples exceeding 10 mg L\-1\) and high conductivity at two monitoring 
sites in the Stillhouse Hollow drainage area (O'Donnell et al. 2006, 
pp. 26, 37). For comparison, nitrate levels in undeveloped Edwards 
Aquifer springs (watersheds without high levels of urbanization) are 
typically close to 1 mg L\-1\ (O'Donnell et al. 2006, p. 26). The 
source of the nitrates in Stillhouse Hollow is thought to be lawn 
fertilizers (Turner 2005b, p. 11). Salamanders observed at the 
Stillhouse Hollow monitoring sites have shown high incidences of 
deformities, such as curved spines, missing eyes, missing limbs or 
digits, and eye injuries (O'Donnell et al. 2006, p. 26). These 
deformities often result in the salamander's inability to feed, 
reproduce, or survive. The Stillhouse Hollow location was also cited as 
having the highest observation of dead salamanders (COA 2001, p. 88). 
Although no statistical correlations were found between the number of 
deformities and nitrate concentrations (O'Donnell et al. 2006, p. 26), 
environmental toxins are the suspected cause of salamander deformities

[[Page 50782]]

(O'Donnell et al. 2006, p. 25). Nitrate toxicity studies have indicated 
that salamanders and other amphibians are sensitive to these pollutants 
(Marco et al. 1999, p. 2,837). Increased nitrate levels have been known 
to affect amphibians by altering feeding activity and causing 
disequilibrium and physical abnormalities (Marco et al. 1999, p. 
2,837).
    In summary, as the human population grows and subsequent 
urbanization occurs within the ranges of these four central Texas 
salamander species, they likely will become more susceptible to the 
effects of excessive nutrients within their surface and subsurface 
habitats. Because of the detrimental effects associated with increased 
nutrient input, we consider nutrients to be an ongoing threat to all 
four central Texas salamanders' continued existence throughout their 
ranges.

Pesticides

    Pesticides are also associated with urban areas. Sources of 
pesticides include lawns, road rights-of-way, and managed turf areas, 
such as golf courses, parks, and ball fields. Pesticide application is 
also common in residential, recreational, and agricultural areas. 
Pesticides have the potential to leach into groundwater through the 
soil or be washed into streams by stormwater runoff.
    Some of the most widely used pesticides in the United States are 
atrazine, carbaryl, diazinon, and simazine (Mahler and Van Metre 2000, 
p. 1). These four pesticides were documented within the Austin blind 
salamander's habitat (Barton Springs Pool and Eliza Springs) in water 
samples taken at Barton Springs during and after a 2-day storm event 
(Mahler and Van Metre 2000, pp. 1, 6, 8). They were found at levels 
below criteria set in the aquatic life protection section of the Texas 
Surface Water Quality Standards (Mahler and Van Metre 2000, p. 4). In 
addition, elevated concentrations of organochlorine pesticides were 
found in Barton Springs sediments (Ingersoll et al. 2001, p. 7). A 
later water quality study at Barton Springs from 2003 to 2005 detected 
atrazine, simazine, prometon, and deethylatrazine in low concentrations 
(Mahler et al. 2006, p. 63). During storm events, additional 
contaminants were detected, including pharmaceutical compounds such as 
caffeine, acetaminophen, and cotinine (Mahler et al. 2006, p. 64). The 
presence of these contaminants in Barton Springs indicates the 
vulnerability of salamander habitat to contaminant infiltration from 
surface land uses.
    Another study by the U.S. Geological Survey detected insecticides 
(diazinon and malathion) and herbicides (atrazine, prometone, and 
simazine) in several Austin-area streams, most often at sites with 
urban and partly urban watersheds (Veenhuis and Slade 1990, pp. 45-47). 
Twenty-two of the 42 selected synthetic organic compounds analyzed in 
this study were detected more often and in larger concentrations at 
sites with more urban watersheds compared to undeveloped watersheds 
(Veenhuis and Slade 1990, p. 61). Other pesticides 
(dichlorodiphenyltrichloroethane, chlordane, hexachlorobenzene, and 
dieldrin) have been detected at multiple Jollyville Plateau salamander 
sites (COA 2001, p. 130).
    The frequency and duration of exposure to harmful levels of 
pesticides have been largely unknown or undocumented for the four 
central Texas salamander species. Therefore, we do not know the extent 
to which pesticides and other waterborne contaminants have affected 
salamander survival, development, and reproduction, or their prey to 
date. However, pesticides are known to impact amphibian species in a 
number of ways. For example, Reylea (2009, p. 370) demonstrated that 
diazinon reduces growth and development in larval amphibians. Another 
pesticide, carbaryl, causes mortality and deformities in larval 
streamside salamanders (Ambystoma barbouri) (Rohr et al. 2003, p. 
2,391). The Environmental Protection Agency (EPA) (2007a, p. 9) also 
found that carbaryl is likely to adversely affect the Barton Springs 
salamander both directly and indirectly through reduction of prey. 
Additionally, atrazine has been shown to impair sexual development in 
male amphibians at concentrations as low as 0.1 part per billion (Hayes 
2002, p. 5,477). Atrazine levels were found to be greater than 0.44 
part per billion after rainfall in Barton Springs Pool (Mahler and Van 
Mere 2000, pp. 4, 12).
    In summary, even though we do not know the extent to which 
pesticides have affected the surface and subsurface habitat of the four 
central Texas salamander species at this time, pesticides do pose a 
significant, ongoing threat to the continued existence of all four 
salamanders throughout their ranges.

Hazardous Material Spills

    The Edwards Aquifer is at risk from a variety of sources of 
pollutants (Ross 2011, p. 4), including hazardous materials that have 
the potential to be spilled, resulting in contamination of both surface 
and groundwater resources (Service 2005, pp. 1.6-14-1.6-15). Any 
activity that involves the extraction, storage, manufacture, or 
transport of potentially hazardous substances, such as fuels or 
chemicals, can contaminate water resources and cause harm to aquatic 
life. Spill events can involve a short release with immediate impacts, 
such as a collision that involves a tanker truck carrying gasoline, or 
the release can be long-term, involving the slow release of chemicals 
over time such as a leaking underground storage tank. As of 1996, more 
than 6,000 leaking underground storage tanks in Texas have resulted in 
contaminated groundwater (Mace et al. 1997, p. 2), including a large 
leak in the range of the Georgetown salamander (Mace et al, 1997, p. 
32). The risk of this type of contamination is expected to increase 
with increasing urbanization.
    The transport of hazardous materials is common on many highways, 
which are major transportation routes (Service 2005, p. 1.6-13). 
Interstate Highway 35 crosses the watersheds that contribute 
groundwater to spring sites known to be occupied by all four salamander 
species. A catastrophic spill could occur if a transport truck 
overturned and its contents entered the recharge zone of the Northern 
Segment of the Edwards Aquifer. Transportation accidents involving 
hazardous materials spills at bridge crossings are of particular 
concern because recharge areas in creek beds can transport contaminants 
directly into the aquifer (Service 2005, p. 1.6-14). Salado salamander 
sites located downstream of Interstate Highway 35 may be particularly 
vulnerable due to their proximity to this major transportation 
corridor. Interstate Highway 35 crosses Salado Creek just 760 to 1,100 
ft (231 to 335 m) from three spring sites (Big Boiling Springs, Lil' 
Bubbly Springs, and Lazy Days Fish Farm) where the Salado salamander is 
known to occur. Should a hazardous materials spill occur at the 
Interstate Highway 35 bridge that crosses at Salado Creek, the Salado 
salamander could be at risk from contaminants entering the water 
flowing into its surface habitat downstream.
    In addition, the Texas Department of Transportation (TxDOT) is 
planning to reconstruct a section of Interstate Highway 35 within the 
Village of Salado (Najvar, 2009, Service, pers. comm., p. 1). This work 
will include replacing four bridges that cross Salado Creek (two main 
lane bridges and two frontage road bridges) in an effort to widen the 
highway at this location. This project could affect the risk of 
hazardous materials spills and runoff into Salado Creek upstream of 
known Salado

[[Page 50783]]

salamander locations. In August 2009, TxDOT began working with the 
Service to identify measures, such as the installation of permanent 
water quality control mechanisms to contain runoff, to protect the 
Salado salamander and its habitat from the effects of this project 
(Najvar 2009, pers. comm., p. 1).
    Austin blind salamander habitat is similarly at risk from hazardous 
material spills that could contaminate groundwater. There is potential 
for a catastrophic gasoline spill in the Barton Springs Segment of the 
Edwards Aquifer, due to the presence of the Longhorn pipeline (Turner 
and O'Donnell 2004, pp. 2-3). Although a number of mitigation measures 
were employed to reduce the risk of a leak or spill from the Longhorn 
pipeline, such a spill could enter the aquifer and result in the 
contamination of salamander habitat at Barton Springs (EPA 2000, pp. 9-
29-9-30).
    Multiple water lines also run through the surrounding areas of 
Barton Springs. A water line break could potentially flow directly into 
Barton Springs, exposing salamanders to chlorine concentrations that 
are potentially toxic (Herrington and Turner 2009, pp. 5, 6). Sewage 
spills are the most common type of spill within the Barton Springs 
watershed and represent a potential catastrophic threat (Turner and 
O'Donnell 2004, p. 27). Sewage spills often include contaminants such 
as nutrients, PAHs, metals, pesticides, pharmaceuticals, and high 
levels of fecal coliform bacteria. Increased ammonia levels and reduced 
dissolved oxygen are the most likely impacts of a sewage spill that 
could cause rapid mortality of large numbers of salamanders (Turner and 
O'Donnell 2004, p. 27). Fecal coliform bacteria cause diseases in 
salamanders and their prey base (Turner and O'Donnell 2004, p. 27). 
Approximately 7,600 wastewater mains totaling 349 mi (561.6 km) are 
present in the Barton Springs Segment of the Edwards Aquifer 
(Herrington et al. 2010, p. 16). In addition, there are 9,470 known 
septic facilities in the Barton Springs Segment as of 2010 (Herrington 
et al. 2010, p. 5), up from 4,806 septic systems in 1995 (COA 1995, p. 
3-13). In one City of Austin survey of these septic systems, over 7 
percent were identified as failing (COA 1995, p. 3-18).
    A contaminant spill could travel quickly through the aquifer to 
Barton Springs, where it could impact Austin blind salamander 
populations. Depending on water levels in the aquifer, groundwater flow 
rates through the Barton Springs Segment of the Edwards Aquifer can 
range from 0.6 mi (1 km) per day to over 4 mi (6 km) per day. The 
relatively rapid movement of groundwater under any flow conditions 
provides little time for mitigation efforts to reduce potential damage 
from a hazardous spill anywhere within the Barton Springs Segment of 
the Edwards Aquifer (Turner and O'Donnell 2004, pp. 11-13).
    A number of point-sources of pollutants exist within the Jollyville 
Plateau salamander's range. Utility structures such as storage tanks or 
pipelines (particularly gas and sewer lines) can accidentally 
discharge. Leaking underground storage tanks have been documented as a 
problem within the Jollyville Plateau salamander's range (COA 2001, p. 
16). Sewage spills from pipelines also have been documented in 
watersheds supporting Jollyville Plateau salamander populations (COA 
2001, pp. 16, 21, 74). For example, in 2007, a sewage line overflowed 
an estimated 50,000 gallons (190,000 liters) of raw sewage into the 
Stillhouse Hollow drainage area of Bull Creek (COA 2007b, pp. 1-3). The 
location of the spill was a short distance downstream of currently 
known salamander locations, and no salamanders were thought to be 
affected.
    The City of Austin also cites swimming pools as a potential threat 
to Eurycea salamanders if pools are drained into waterways or storm 
drains without dechlorination (COA 2001, p. 130). This is due to the 
concentrations of chlorine commonly used in residential swimming pools, 
which far exceed the lethal concentrations observed in experiments with 
the San Marcos salamander (Eurycea nana) (COA 2001, p. 130). 
Residential swimming pools can be found throughout the watersheds of 
several Jollyville Plateau salamander sites and may pose a risk to the 
salamanders if discharged into the storm drain system or waterways.
    Data on chemical spills near the City of Georgetown are lacking, 
but the threat of groundwater contamination from accidental spills is 
still present. As recently as 2011, a fuel tanker overturned in 
Georgetown and spilled 3,500 gallons (13,249 liters) of gasoline 
(McHenry et al. 2011, p. 1). A large plume of hydrocarbons was detected 
within the Edwards Aquifer underneath Georgetown in 1997 (Mace et al, 
1997, p. 32), probably the result of a leaking fuel storage tank. There 
are currently eight water treatment plants within the city limits, with 
wastewater and chlorinated drinking water lines running throughout 
Georgetown salamander stream drainages (City of Georgetown 2008, p. 
3.37). A ``massive'' wastewater line is being constructed in the South 
San Gabriel River drainage (City of Georgetown 2008, p. 3.22), which is 
within the watershed of one known Georgetown salamander site. Almost 
700 septic systems were permitted or inspected in Georgetown in 2006 
(City of Georgetown 2008, p. 3.36). Even though data on chemical spills 
near the City of Georgetown are lacking, there is the potential for 
spills and contamination to occur from multiple sources.
    Several groundwater contamination incidents have occurred within 
Salado salamander habitat (Price et al. 1999, p. 10). Big Boiling 
Springs is located on the south bank of Salado Creek, near locations of 
past contamination events (Chippindale et al. 2000, p. 43). Between 
1989 and 1993, at least four incidents occurred within a quarter mile 
(0.4 km) from the spring site, including a 700-gallon (2,650-liter) and 
400-gallon (1,514-liter) gasoline spill and petroleum leaks from two 
underground storage tanks (Price et al. 1999, p. 10). Because no 
follow-up studies were conducted, we have no information to indicate 
what effect these spills had on the species or its habitat. However, 
between 1991 and 1998, only a single salamander was observed at Big 
Boiling Springs (TPWD 2011a, p. 2).
    In summary, catastrophic hazardous material spills pose a potential 
significant threat to the Austin blind, Georgetown, and Salado 
salamanders due to their restricted ranges. A significant hazardous 
materials spill within a stream drainage for any of these species could 
have the potential to threaten the long-term survival and 
sustainability of multiple populations or possibly an entire species. 
The threats from spills increase substantially under drought conditions 
due to lower dilution and buffering capability of impacted waterbodies. 
Spills under low flow conditions are predicted to have an impact at 
much smaller volumes (Turner and O'Donnell 2004, p. 26). For example, 
it is predicted that at low flows (10 cubic feet per second [cfs]) a 
spill of 360 gallons (1,362.7 liters) of gasoline 3 miles (4.8 km) from 
Barton Springs could be catastrophic for the Austin blind salamander 
population (Turner and O'Donnell 2004, p. 26). Because the Austin blind 
salamander resides in only one spring system, a catastrophic spill in 
its surface and subsurface habitat could cause the extinction of this 
species in the wild. However, because the Jollyville Plateau salamander 
occurs in more populations over a broader range, the potential for a 
catastrophic hazardous materials spill to affect the overall species' 
status is small.

[[Page 50784]]

A hazardous materials spill has the potential to cause localized 
populations to go extinct, but we do not consider this to be a threat 
to the Jollyville Plateau salamander's overall continued existence. 
But, in combination with the other threats identified in this five-
factor analysis, we think a catastrophic hazardous materials spill 
could contribute to the species' risk of extinction by reducing its 
long-term viability. We, therefore, consider hazardous material spills 
to be a potential significant threat for the Austin blind and Salado 
salamander due to their limited distributions. Hazardous material 
spills are less of a threat for the more widespread Georgetown 
salamander. These spills pose a low risk to the Jollyville Plateau 
salamander due to its more widespread distribution.

Construction Activities

    Short-term increases in pollutants, particularly sediments, can 
occur during construction in areas of new development. When vegetation 
is removed and rain falls on unprotected soils, large discharges of 
suspended sediments can erode from newly exposed areas, resulting in 
increased sedimentation in downstream drainage channels (Schueler 1987, 
pp. 1-4; Turner 2003, p. 24; O'Donnell et al. 2005, p. 15). This 
increased sedimentation from construction activities has been linked to 
declines in Jollyville Plateau salamander counts at multiple sites 
(Turner 2003, p. 24; O'Donnell et al. 2006, p. 34). Cave sites are also 
impacted by construction, as Testudo Tube Cave (Jollyville Plateau 
salamander habitat) showed an increase in nickel, calcium, and nitrate/
nitrite after nearby road construction (Richter 2009, pp. 6-7). Barton 
Springs (Austin blind salamander habitat) is also under the threat of 
pollutant loading due to its proximity to construction activities and 
location at the downstream side of the watershed (COA 1997, p. 237). 
The City of Austin (1995, p. 3-11) estimated that construction-related 
sediment and in-channel erosion accounted for approximately 80 percent 
of the average annual sediment load in the Barton Springs watershed. In 
addition, the City of Austin (1995, p. 3-10) estimated that total 
suspended sediment loads have increased 270 percent over pre-
development loadings within the Barton Springs Segment of the Edwards 
Aquifer. At this time, we are not aware of any studies that have 
examined sediment loading due to construction activities within the 
watersheds of Georgetown or Salado salamander habitats. However, 
because construction occurs in many of these watersheds, we believe 
that the threat of construction in areas of new development applies to 
these species as well. Construction is intermittent and temporary, but 
it affects both surface and subsurface habitats. Therefore, we have 
determined that this threat is ongoing and is and will continue to 
affect the Austin blind, Jollyville Plateau, and Georgetown salamanders 
and their habitats. However, we consider this threat to affect the 
Salado salamander to a lesser degree due to the relatively low levels 
of impervious cover in its range.
    Also, the physical construction of pipelines has the potential to 
modify subsurface habitat for salamander species. It is known that 
these salamanders inhabit the subsurface environment. Tunneling for 
underground pipelines can destroy potential habitat by removing 
subsurface material. Additional material can become dislodged and 
result in increased sediment loading into the aquifer and associated 
spring systems. In addition, disruption of water flow to springs 
inhabited by salamanders can occur through the construction of tunnels 
and vertical shafts. Because detailed maps of the underground conduits 
that feed springs in the Edwards Aquifer are not available, tunnels and 
shafts have the possibility of intercepting and severing those conduits 
(COA 2010b, p. 28). Affected springs could rapidly become dry and would 
not support salamander populations. The closer a shaft or tunnel 
location is to a spring, the more likely that the construction will 
impact a spring (COA 2010b, p. 28). This has presumably occurred in the 
past at Moss Gulley Spring, where the drilling of a nearby test well in 
the mid-1980s led to the dewatering of the spring (Hillis et al. 2010, 
p. 2). Jollyville Plateau salamanders have not been observed at that 
site since the spring stopped flowing (Hillis et al. 2010, p. 2). Even 
small shafts pose a threat to nearby spring systems, and therefore, we 
consider construction of pipelines to be a future threat to the surface 
and subsurface habitat of all four salamander species. However, we 
consider this a low significance threat for the Jollyville Plateau 
salamander because tunnels or shafts are likely to only impact a few 
populations. Because there are currently no known projects that are 
likely to occur within the species' range, we consider this a threat of 
low significance for the Austin blind, Georgetown, and Salado 
salamanders.
    Likewise, we consider tunnel and shaft construction to be a threat 
to the Jollyville Plateau salamander's surface and subsurface habitat 
due to its potential to intercept groundwater flow and dewatering. In 
2011, construction began on the Jollyville Transmission Main (JTM), a 
tunnel designed to transport treated drinking water from Water 
Treatment Plant No. 4 to the Jollyville Reservoir. The project also 
includes four working shafts along the tunnel route (COA 2010b, p. 1). 
Because the tunnel is being constructed below the Edwards Aquifer and 
below the permeable portion of the Glen Rose formation (COA 2010b, p. 
42; Toohey 2011, p. 1; COA 2011c, p. 36, 46), the threat to the 
salamander from this particular tunnel is considered low. The vertical 
shafts that are being drilled down through the Edwards Aquifer are a 
more significant concern.
    Of the four shafts, only the one at the Four Points location 
appears to be a potential threat to any Jollyville Plateau salamanders. 
The Parks and Recreation Department (PARD) shaft is in the Glen Rose 
(not the Edwards) formation (Service 2010a; COA 2011c, p. 33) and 
therefore is not expected to affect Edwards Aquifer groundwater. The 
Jollyville Reservoir Shaft is on the other side of a groundwater divide 
from any springs within a mile of the site (Service 2010a). The shaft 
at the water treatment plant is going through a portion of the Edwards 
formation that is dry (COA 2011c, p. 33). There are 8 of 92 known 
Jollyville Plateau salamander sites within 1 mi (1.6 km) of the Four 
Points shaft location. The closest locations (Spring 21 and Spring 24) 
are about 2,000 ft (610 m) or greater from the shaft. Best management 
practices designed to protect groundwater resources have been 
implemented into the design and construction of the JTM shafts. These 
practices include, but are not limited to: Monitoring groundwater 
quality and spring flow, minimizing sediment discharges during 
construction, developing a groundwater impact contingency plan, 
locating working shafts in areas where the chance of encountering 
conduits to salamander springs is reduced, and re-routing conduit flow 
paths around the shaft if encountered (COA 2010b, pp. 51-55).
    We believe that these best management practices have lowered the 
magnitude of the threat to the Jollyville Plateau salamander. However, 
a leak occurred at one shaft site (Four Points) in December 2011, and 
it was associated with an initial 1-foot (0.3 m) drop in the aquifer 
level (Toohey 2011, p. 2) as measured in a monitoring well 10 ft (3 m) 
away. A 1-foot (0.3-m) drop in water level was also seen in a 
monitoring well 100 ft (30 m) away, but not in

[[Page 50785]]

monitoring wells farther out. The City did not see any drops in flow at 
the springs they were monitoring or in wells between those springs and 
the well 100 ft away; however, they do not have access to the closest 
springs (mentioned above). Since that time, grout has been injected 
into the shaft wall to stop the leak. Preliminary evidence indicates 
that the grout injection resulted in a tight seal at the site of the 
leak (Lesniak 2012, City of Austin, pers. comm.). Even so, we consider 
tunnel and shaft construction of the JTM to be a threat now to the 
Jollyville Plateau salamander's habitat due to its potential to 
intercept groundwater flow and to dewater; however, we consider this 
threat to be of low significance because the best management practices 
have been implemented into the design and construction of the JTM 
shafts to protect groundwater resources.
    Lastly, limestone rock is an important raw material that is mined 
in quarries all over the world due to its popularity as a building 
material and its use in the manufacture of cement (Vermeulen and 
Whitten 1999, p. 1). The construction activities within rock quarries 
can permanently alter the geology and groundwater hydrology of the 
immediate area, and adversely affect springs that are hydrologically 
connected to impacted sites. The potential environmental impacts of 
quarries include outright destruction of springs or collapse of karst 
caverns, as well as impacts to water quality through siltation and 
sedimentation, and impacts to water quantity through water diversion, 
dewatering, and reduced flows (Ekmekci 1990, p. 4). Limestone is a 
common geologic feature of the Edwards Aquifer, and active quarries 
exist throughout the region. For example, at least three Georgetown 
salamander sites (Avant Spring, Knight (Crockett Gardens) Spring, and 
Cedar Breaks Hiking Trail Spring) occur adjacent to a limestone quarry 
that has been active since at least 1995. The population status of the 
Georgetown salamander is unknown at Knight Spring and Cedar Breaks 
Hiking Trail Spring, but salamanders are seen infrequently and in low 
abundance at the closest spring to the quarry (Avant Spring; Pierce 
2011c, pers. comm.). Because quarries may only affect a small portion 
of the species' ranges, we consider the mining of limestock rock to be 
an ongoing threat with limited effect to the Georgetown, Jollyville 
Plateau, and Salado salamanders, but not the Austin blind salamander. 
The Austin blind salamander's range is located in downtown Austin, and 
there are no active limestone quarries within the species' range.

Water Quantity Reduction in Relation to Urbanization

    The Northern Segment of the Edwards Aquifer is the primary supply 
of water for Jollyville Plateau, Georgetown, and Salado salamander 
habitat (Cole 1995, p. 33; TPWD 2011a, p. 3). In general, the aquifer 
has been described as localized, small, and highly susceptible to 
drying or draining (Chippindale et al. 2000, p. 36).
    Urbanization and rapid population growth in the Northern Segment of 
the Edwards Aquifer may contribute to reduced spring flows due to 
increases in groundwater pumping. From 1980 to 2000, groundwater 
pumping in the Northern Segment of the Edwards Aquifer nearly doubled 
(TWDB 2003, pp. 32-33). The City of Georgetown predicts the average 
water demand to increase from 8.21 million gallons per day in 2003, to 
10.9 million gallons per day by 2030 (City of Georgetown 2008, p. 
3.36). Under peak flow demands (18 million gallons per day in 2003), 
the City of Georgetown uses seven groundwater wells in the Edwards 
Aquifer (City of Georgetown 2008, p. 3.36). Total water use for 
Williamson County was 73,532 ac ft in 2010, and is projected to 
increase to 98,268 ac ft by 2020, and to 211,854 ac ft by 2060, 
representing a 188 percent increase over the 50-year period (TWDB 2010, 
p. 46). Similarly, Bell County and Travis County expect a 59 percent 
and 91 percent increase in total water use over the same 50-year 
period, respectively (TWDB 2010, pp. 46, 64).
    One prediction of future groundwater use in this area suggests a 
large drop in pumping as municipalities convert from groundwater to 
surface water supplies (TWDB 2003, p. 65). However, it is unknown if 
this reduction in groundwater use translates to adequate spring flows 
for salamanders. Increased urbanization in the watershed has been cited 
as one factor, in combination with drought, causing declines in spring 
flows (City of Austin 2006, pp. 46-47; TPWD 2011a, pp. 4-5). 
Urbanization removes the ability of the watershed to allow slow 
filtration of water through soils following rain events. Instead 
rainfall runs off impervious surfaces and into stream channels at 
higher rates, increasing downstream flows and decreasing groundwater 
recharge (Miller et al. 2007, p. 74).
    The City of Austin found a negative correlation between 
urbanization and spring flows at Jollyville Plateau salamander sites 
(Turner 2003, p. 11). Field studies have also shown that a number of 
springs that support Jollyville Plateau salamanders have already gone 
dry periodically, and that spring waters resurface following rain 
events (O'Donnell et al. 2006, pp. 46-47). The San Gabriel Springs 
(Georgetown salamander habitat) are now intermittently flowing in the 
summer due to pumping from nearby water wells (TPWD 2011a, p. 9). 
Salamanders have not been seen on the surface there since 1991 
(Chippindale et al. 2000, p. 40; Pierce 2011b, pers. comm.).
    In combination with drought, groundwater pumping has a direct 
impact on spring flows. Groundwater availability models demonstrate 
that 1 cfs of pumping will diminish Barton Springs spring flow by 1 cfs 
under drought-of-record (1950s drought) conditions (Smith and Hunt 
2004, pp. 24, 36). Under the same conditions, these models suggest that 
present-day pumping rates will temporarily cease Barton Springs flow on 
a daily basis (Smith and Hunt 2004, pp. 24, 36).
    Groundwater pumping can lead to saline water encroachments in the 
aquifer. As groundwater levels decline, a decrease in hydrostatic 
pressure occurs and saline groundwater is able to penetrate up into the 
lower portion of the aquifer (Pavlicek et al. 1987, p. 2). This saline 
water encroachment would threaten the freshwater biota in the springs 
and the aquifer, including the four central Texas salamander species 
and their prey, by dramatically increasing the water salinity. Water 
quality in the Barton Springs Segment of the Edwards Aquifer has been 
degraded in the past due to saline encroachment (Slade et al. 1986, p. 
62). This water quality degradation occurred when Barton Springs 
discharge was less than 30 cfs (Slade et al. 1986, p. 64). An analysis 
of more recent data found similar declines in water quality as the flow 
of Barton Springs dropped into the 20 to 30 cfs range (Johns 2006, pp. 
6-7). As mentioned earlier, reduced groundwater levels would also 
increase the concentration of pollutants in the aquifer. Flows at 
Barton Springs dropped below 17 cfs as recently as mid-November 2011 
(Barton Springs/Edwards Aquifer Conservation District 2011, p. 1).
    Although water quantity decreases and spring flow declines are 
cited as a threat to Eurycea salamanders (Corn et al. 2003, p. 36; 
Bowles et al. 2006, p. 111), these species display some adaptive 
behavior to deal with periods of periodic surface flow losses. All four 
salamander species apparently spend some part of their life history in 
underground aquatic habitats and have the ability to retreat 
underground when

[[Page 50786]]

surface flows decline. For example, one of the City of Austin 
monitoring sites where Jollyville Plateau salamanders are most abundant 
undergoes periods where there is no surface water habitat available for 
the salamander (O'Donnell et al. 2006, p. 47). Jollyville Plateau 
salamander juveniles were observed at Lanier Spring following 10 months 
of dry conditions on the surface, indicating that the salamanders are 
likely able to reproduce in the subsurface environment during a drought 
(Bendik 2011a, p. 32). Salado salamanders also reappeared in Robertson 
Springs after the springs went temporarily dry in 2009 (TPWD 2011a, p. 
5). However, drying spring habitats can result in stranding 
salamanders, resulting in death of individuals (O'Donnell et al. 2006, 
p. 16). It is also known that prey availability for carnivores is low 
underground due to the lack of primary production (Hobbs and Culver 
2009, p. 392). This is supported by recent evidence of ``shrinkage'' in 
Jollyville Plateau salamander body length following periods of no 
springflow (Bendik 2011b, pers. comm.). Length measurements taken 
during a COA mark-recapture study at Lanier Spring demonstrated that 
Jollyville Plateau salamanders had negative growth during a 10-month 
period of no springflow in 2008-2009 (Bendik 2011b, pers. comm.). 
Therefore, although central Texas salamanders can survive and reproduce 
underground, the best available scientific evidence shows that these 
animals need the energy-rich surface habitat for positive growth and 
development.
    In summary, water quantity reduction in relation to urbanization is 
an ongoing threat to all four salamanders throughout their ranges, 
primarily due to increased groundwater pumping in the presence of 
drought conditions and potential increases in saline water 
encroachments in the aquifer. However, we believe this threat is having 
or likely to have only a moderate effect, because the salamanders have 
the ability to retreat underground when surface flows decline.

Physical Modification of Surface Habitat

    All four salamanders are sensitive to direct physical modification 
of surface habitat from impoundments, feral hogs, livestock, and other 
human activities. Because these threats only impact the surface habitat 
of salamanders, and because each species has the ability to retreat to 
subsurface habitats for shelter, none of these threats is likely to 
result in a significant impact to the species or their habitat. 
However, in combination with other threats discussed above, these 
threats may contribute to the species' risk of extinction.

Impoundments

    Impoundments disrupt the natural flow regime of streams, leading to 
a variety of stressors that impact the salamanders and their surface 
habitats. For example, a low water crossing on a tributary of Bull 
Creek, occupied by the Jollyville Plateau salamander, resulted in 
sediment build-up below the impoundment and a scour hole above the 
impoundment that supported predaceous fish (O'Donnell et al. 2008, p. 
1). As a result, Jollyville Plateau salamanders were not found in this 
degraded habitat after the impoundment was constructed. When the 
crossing was removed in October 2008, the sediment build-up was 
removed, the scour hole was filled, and salamanders were later observed 
(Bendik 2011b, pers. comm.). Many low-water crossings are present near 
other Jollyville Plateau salamander sites (Bendik 2011b, pers. comm.). 
Impoundments only impact the surface habitat of salamanders. Because 
impoundments are likely to impact a small portion of the species' 
range, we consider impoundments caused by low-water crossings to be an 
ongoing threat of limited effect on the Jollyville Plateau salamander 
and its surface habitat, now and in the future.
    Impoundments have also impacted surface habitat for the other 
salamander species. Most of the spring outlets in the Village of 
Salado, including the Salado salamander type locality at Big Boiling 
Springs, were modified by dam construction in the mid-1800s, to supply 
power to various mills (Brune 1981, p. 67). Two sites for the 
Georgetown salamander have spring openings that are confined to brick 
and mortar spring boxes (White 2011, SWCA, pers. comm.; Booker 2011, p. 
1), presumably to collect the spring water for cattle. All spring sites 
for the Austin blind salamander (Main, Eliza, and Sunken Garden 
springs) have been impounded for recreational use. These sites were 
impounded in the early to mid-1900s. For example, Eliza Spring now 
discharges from 7 openings (each 1 ft (0.3 m) in diameter) in the 
concrete floor and 13 rectangular vents along the edges of the 
concrete. While the manmade structures help retain water in the spring 
pools during low flows, they have altered the salamander's natural 
environment. The impoundments have changed the Barton Springs ecosystem 
from a stream-like system to a more lentic (still water) environment, 
thereby reducing the water system's ability to flush sediments 
downstream and out of salamander habitat. Although a natural surface 
flow connection between Sunken Gardens Spring and Barton Creek has been 
restored recently (COA 2007c, p. 6), the Barton Springs system as a 
whole remains highly modified. Therefore, we consider impoundments to 
be an ongoing threat to the Salado, Georgetown, and Austin blind 
salamanders and their surface habitat, now and in the future. This 
threat has a limited effect on the Salado and Georgetown salamanders 
because it impacts a small portion of the species' ranges, but has a 
large effect on the Austin blind salamander because it affects this 
species' entire range.

Feral Hogs

    There are between 1.8 and 3.4 million feral hogs (Sus scrofa) in 
Texas (TAMU 2011, p. 2). They prefer to live around moist areas, 
including riparian areas near streams, where they can dig into the soft 
ground for food and wallow in mud to keep cool (Mapson 2004, pp. 11, 
14-15). Feral hogs disrupt these ecosystems by decreasing plant species 
diversity, increasing invasive species abundance, increasing soil 
nitrogen, and exposing bare ground (Texas A&M University (TAMU) 2012, 
p. 4). Feral hogs negatively impact surface salamander habitat by 
digging and wallowing in spring heads, which increases sedimentation 
downstream (O'Donnell et al. 2006, pp. 34, 46). They have been cited as 
a source of elevated bacteria, nitrates, and phosphorus to streams in 
the Austin area (Timmons et al. 2011, pp. 1-2).
    Feral hogs have become abundant in some areas where the Jollyville 
Plateau, Georgetown, and Salado salamanders occur. O'Donnell et al. 
(2006, p. 34) noted that feral hog activity was increasing in the Bull 
and Cypress creek watersheds. Evidence of hogs has also been observed 
near one Georgetown salamander site (Cobbs Spring) (Booker 2011, p. 1). 
The landowner of Cobbs Spring is actively trapping feral hogs (Booker 
2011, p. 1), but the effectiveness of this management has not been 
assessed. Feral hogs are also present in the area of several Salado 
salamander sites. Fortunately, feral hogs cannot access Austin blind 
salamander sites due to fencing and their location in downtown Austin.
    In summary, because of their abundance and potential to negatively 
impact surface salamander habitat, we consider feral hogs to be an 
ongoing threat of low significance to the Jollyville Plateau, 
Georgetown, and Salado salamanders. As previously stated, we do not 
consider feral hogs to

[[Page 50787]]

be a threat to the Austin blind salamander at this time.

Livestock

    Similar to feral hogs, livestock can negatively impact surface 
salamander habitat by disturbing the substrate and increasing 
sedimentation in the spring run where salamanders are often found. 
Poorly managed livestock grazing results in changes in vegetation (from 
grass-dominated to brush-dominated), which leads to increased erosion 
of the soil profile (COA 1995, p. 3-59). Grazing near streams can 
negatively impact nutrients, bacteria, species diversity, and water 
temperature in stream systems (COA 1995, p. 3-62). Evidence of 
trampling and grazing in riparian areas from cattle can be found at one 
Georgetown salamander site (White 2011, SWCA, pers. comm.), and cattle 
are present on at least one other Georgetown salamander site. Cattle 
are also present on lands where four Salado salamander sites occur 
(Gluesenkamp 2011b, pers. comm.; Texas Section Society for Range 
Management 2011, p. 2). Austin blind salamander habitat is inside a 
City of Austin park, and livestock are not allowed in the spring areas. 
Much of the Jollyville Plateau salamander habitat is in suburban areas, 
and we are not aware of livestock damage in those areas.
    There is some management of livestock occurring that reduces the 
magnitude of negative impacts. An 8,126-ac (3,288-ha) property in Bell 
County with at least three Salado salamander sites has limited its 
cattle rotation to a maximum of 450 head (Texas Section Society for 
Range Management 2011, p. 2), which is considered a moderate stocking 
rate. The landowners at four of the springs with Salado salamanders 
have been considering options for fencing off spring outlets to protect 
the salamander habitat from cattle damage (Harrell 2012, Service, pers. 
comm.). In addition, the landowner of Cobbs Spring (a Georgetown 
salamander site) is in the process of phasing out cattle on the 
property (Boyd 2011, Williamson County Conservation Foundation, pers. 
comm.).
    In summary, even though livestock may be having impacts at four of 
the seven Salado salamander spring sites, we believe livestock to be an 
ongoing threat of low impact to this salamander's habitat because there 
is some management of the livestock that reduces the magnitude of 
negative impacts. Even though habitat degradation by livestock is a 
factor that seems to be impacting the habitat of the Georgetown 
salamander, we do not believe it is occurring at a scale that 
significantly contributes to the risk of extinction of the species on 
its own. However, in combination with the other threats identified in 
this five-factor analysis, we think livestock may be contributing to 
the species' risk of extinction by reducing its long-term viability. 
Livestock are not a threat to the continued existence of the Austin 
blind or Jollyville Plateau salamanders.

Other Human Activities

    Some sites for the four central Texas salamanders have been 
directly modified by human-related activities. In the summer of 2008, a 
spring opening at a Salado salamander site was covered with gravel 
(Service 2010b, p. 6). Although we received anecdotal information that 
at least one salamander was observed at the site after the gravel was 
dumped at Big Boiling Springs, the Service has no detailed information 
on how the Salado salamander was affected by this action. Heavy 
machinery is continuously used in the riparian area of Big Boiling and 
Lil' Bubbly Springs to clear out vegetation and maintain a grassy lawn 
to the water's edge (Gluesenkamp 2011a,b, pers. comm.), which has led 
to erosion problems during flood events (TPWD 2011a, p. 6). The 
modification of springs for recreation or other purposes degrades 
natural riparian areas, which are important for controlling erosion and 
attenuating floodwaters in aquatic habitats. Other continuing human 
activities at Big Boiling Spring include pumping water from the spring 
opening, contouring the substrate of the spring environment, and 
covering spring openings with gravel (TPWD 2011a, p. 4). For example, 
in the fall of 2011, the outflow channels and edges of these two 
springs were reconstructed with large limestone blocks and mortar. In 
addition, in response to other activity in the area, the U.S. Army 
Corps of Engineers issued a cease and desist order to the Salado 
Chamber of Commerce in October 2011, for unauthorized discharge of 
dredged or fill material that occurred in this area (Brooks 2011, U.S. 
Corps of Engineers, pers. comm.). This order was issued in relation to 
the need for a section 404 permit under the Clean Water Act (33 U.S.C. 
1251 et seq.). Also in October 2011, a TPWD game warden issued a 
citation to the Salado Chamber of Commerce due to the need for a sand 
and gravel permit from the TPWD for work being conducted within TPWD's 
jurisdiction (Heger 2012a, TPWD, pers. comm.). The citation was issued 
because the Salado Chamber of Commerce had been directed by the game 
warden to stop work within TPWD's jurisdiction, which Salado Chamber of 
Commerce did temporarily, but work started again in spite of the game 
warden's directive (Heger 2012a, pers. comm.). A sand and gravel permit 
was obtained on March 21, 2012. The spring run modifications were 
already completed by this date, but further modifications in the 
springs were prohibited by the permit. Additional work on the bank 
upstream of the springs was permitted and completed (Heger 2012b, pers. 
comm.).
    Because the Salado salamander is only known from seven spring 
locations, any type of human-related activities, such as pumping water 
from a spring opening, contouring the substrate of a spring 
environment, and covering spring openings with gravel, may have 
significant detrimental effects on the salamander and its habitat. 
These activities only affect the surface salamander habitat. Therefore, 
we consider these types of human-related activities to be ongoing 
threats of low impact to the Salado salamander's continued existence.
    Furthermore, frequent human visitation associated with easily 
accessed habitat of the four salamanders may negatively affect the 
species and their habitat. Documentation from the City of Austin of 
disturbed vegetation, vandalism, and the destruction of travertine 
deposits (fragile rock formations formed by deposit of calcium 
carbonate on stream bottoms) by foot traffic has been documented at one 
of their Jollyville Plateau salamander monitoring sites in the Bull 
Creek watershed (COA 2001, p. 21) and may result in direct destruction 
of small amounts of the salamander's habitat. Eliza Spring and Sunken 
Garden Spring, two of the three locations of the Austin blind 
salamander, also experience vandalism, despite the presence of fencing 
and signage (Dries 2011, City of Austin, pers. comm.). The deep water 
of the third location (Main Pool) likely protects the Austin blind 
salamander's surface habitat from damage from frequent human 
recreation. Therefore, we consider human visitation to be an ongoing 
threat of low impact to the Jollyville Plateau salamander, and a threat 
of moderate impact to the Austin blind salamander, now and in the 
future.
    Lastly, at the complex of springs occupied by the Georgetown 
salamander within San Gabriel River Park, a thick bed of nonnative 
granite gravel has been placed in the spring runs (TPWD 2011a, p. 9). 
This pea gravel is too small to serve as cover habitat and does not 
form the interstitial spaces required for

[[Page 50788]]

Georgetown salamanders. Salamanders have not been observed here since 
1991 (Chippindale et al. 2000, p. 40; Pierce 2011b, pers. comm.). 
Gravel dumping has not been documented at any other Georgetown 
salamander sites. Because this activity may have contributed to the 
decline of only this single population, we do not consider substrate 
modification in the form of gravel dumping to be a threat to the 
existence of the Georgetown salamander by itself. However, in 
combination with the other threats identified in this five-factor 
analysis, we think substrate modification may be contributing to the 
species' risk of extinction by reducing its long-term viability.

Drought and Flooding

    Broad drought and flooding events have proven to have large impacts 
on the central Texas salamanders by drastically reducing or increasing 
the amount of water and affecting habitat quality.

Drought

    The presence of water is an essential component to salamander 
habitat. Drought conditions alter the hydrologic conditions resulting 
in lowering groundwater tables and reduced spring flows. The impacts of 
drought are compounded by other consumptive uses of the aquifer such as 
groundwater pumping. The Northern Segment of the Edwards Aquifer, which 
supplies water to Jollyville Plateau, Georgetown, and Salado salamander 
habitat, is vulnerable to drought (Chippindale et al. 2000, p. 36). In 
particular, the portion of the Edwards Aquifer underlying the 
Jollyville Plateau is relatively shallow, with a high elevation, thus 
being unlikely to be able to sustain spring flows during periods of 
drought (Cole 1995, pp. 26-27). Drought in the watershed has been cited 
as one factor, in combination with urbanization, causing declines in 
spring flows (O'Donnell et al. 2006, pp. 46-47). A recent drought 
lasting from 2008 to 2009 was considered one of the worst droughts in 
central Texas history and caused numerous Jollyville Plateau salamander 
sites to go dry (Bendik 2011a, p. 31). An even more pronounced drought 
throughout Texas began in 2010, with the period from October 2010, 
through September 2011, being the driest 12-month period in Texas since 
rainfall records began (LCRA 2011, p. 1). Rainfall in early 2012 has 
lessened the intensity of the current drought, but below average 
rainfall and above average temperatures are forecasted for the summer 
of 2012 (LCRA 2012, p. 1).
    Low flow conditions during drought also have negative impacts to 
the Austin blind salamander and its ecosystem in the Edwards Aquifer 
and at Barton Springs. The long-term average flow at the Barton Springs 
outlets is approximately 53 cfs (City of Austin 1998, p. 13; Smith and 
Hunt 2004, p. 10). The lowest flow recorded at Barton Springs was about 
10 cfs during a record drought in the 1950s (COA 1998, p. 13). 
Discharge at Barton Springs decreases as water levels in the Barton 
Springs Segment of the Edwards Aquifer drop. Decreased discharge is 
associated with increases in water temperature, decreases in spring 
flow speed, and increases in sedimentation (COA 2011d, pp. 19, 24, 27). 
Large declines in aquifer levels have historically been due to a lack 
of adequate rainfall recharging the aquifer. In a 2004 groundwater flow 
modeling study, the Barton Springs Edwards Aquifer Conservation 
District predicted that under drought-of-record conditions and current 
pumping levels, the mean monthly springflow would be about 1 cfs. This 
study also indicated that under drought-of-record conditions, projected 
pumping rates for future years would cause Barton Springs to cease 
flowing for at least 4 months out of a year (Smith and Hunt 2004, pp. 
1, 20, 24).
    The specific effects of low flow on central Texas salamanders can 
be inferred by examining studies on the Barton Springs salamander. 
Drought decreases spring flow and dissolved oxygen levels and increases 
temperature in Barton Springs (Turner 2004, p. 2; Turner 2009, p. 14). 
Low dissolved oxygen levels decrease reproduction in Barton Springs 
salamanders (Turner 2004, p. 6; 2009, p. 14). Turner (2009, p. 14) also 
found that Barton Springs salamander counts decline with decreasing 
discharge (and thus declining dissolved oxygen levels). A prolonged 
drought from June 2008 through September 2009 caused decreases in 
Barton Springs salamander abundance (COA 2011d, pp. 19, 24, 27). The 
drought in 2011 resulted in dissolved oxygen concentrations so low that 
City of Austin used an aeration system to maintain oxygenated water in 
Eliza and Sunken Gardens Springs (Dries 2011, City of Austin, pers. 
comm.). Drought also lowers water quality in Barton Springs due to 
saline water encroachments in the Barton Springs Segment of the Edwards 
Aquifer (Slade et al. 1986, p. 62; Johns 2006, p. 8).
    In summary, we consider drought to be an ongoing threat to all four 
salamanders, because it can cause direct mortality to salamanders by 
desiccation if they are unable to retreat underground, it increases 
competition for spaces and resources (Bendik 2011a, p. 31), and it 
negatively affects their habitat, as discussed above. However, we 
consider the threat of drought to have a limited impact to all four 
central Texas salamanders and their habitats because they may be 
evolutionarily adapted to drought conditions that are common to the 
region (Bendik 2011a, pp. 31-32). At the same time, climate change and 
groundwater pumping may exacerbate drought conditions to the point 
where salamanders cannot adapt (see ``Climate Change'', below, and 
``Water Quantity Reduction in Relation to Urbanization'', above).

Flooding

    Flooding as a result of rainfall events can dramatically alter the 
substrate and hydrology of salamander habitat. A flood event in 
September 2010 modified surface habitat for the Georgetown salamander 
at two sites (Pierce 2011a, p. 10). The stormwater runoff caused 
erosion, scouring of the streambed channel, the loss of large rocks, 
and the creation of several deep pools. Salamander densities dropped 
dramatically in the days following the flood, and at one site, remained 
at low levels until habitat restoration (returning large rocks to the 
spring run) took place in the spring of 2011 (Pierce 2011a, p. 11). 
Likewise, three storm events in 2009 and 2010 deposited sediment and 
other material on top of spring openings at Salado Spring, preventing 
salamanders from foraging (TPWD 2011a, p. 6). The increased flow rate 
from flooding causes unusually high dissolved oxygen concentrations, 
which may exert direct or indirect, sub-lethal effects (reduced 
reproduction or foraging success) on salamanders (Turner 2009, p. 11). 
In addition, Geismar (2005, p. 2) found that flooding increases 
contaminants and sediments in Barton Springs. In 2007, flooding 
resulted in repeated accumulation of sediment in the Main Pool of 
Barton Springs that was so rapid that cleaning by City of Austin staff 
was not frequent enough to keep the surface habitat from becoming 
embedded (COA 2007c, p. 4). Flooding likely has similar effects on 
contaminants and sediments in other salamander habitat, but we are not 
aware of other studies.
    The four salamanders' surface habitat is characterized by shallow 
water depth (COA 2001, p. 128; Pierce 2011a, p. 3), but deep pools are 
sometimes formed within stream channels from the scouring of floods. 
Tumlison et al. (1990, p. 172) found that the abundance of one Eurycea 
species decreased as

[[Page 50789]]

water depth increased. This relationship may be caused by an increase 
in predation pressure, as deeper water supports predaceous fish 
populations. However, several central Texas Eurycea species are able to 
thrive in deep water environments in the presence of many predators 
(for example, San Marcos salamander in Spring Lake, Eurycea sp. in 
Landa Lake, Barton Springs salamander in Barton Springs Pool). Anti-
predator behaviors may allow these species to co-exist with predaceous 
fish, and the effectiveness of these behaviors may be species-specific 
(reviewed in Pierce and Wall 2011, pp. 18-19). The specific resistance 
to predation from fish for the four central Texas salamanders is 
unknown. In any case, flooding can alter the surface habitat by 
deepening stream channels, which may increase predaceous fish.
    Also, salamanders may be flushed from the surface habitat by strong 
flows during flooding. Bowles et al. (2006, p. 117) observed no 
Jollyville Plateau salamanders in riffle habitat at one site during 
high water velocities and hypothesized that individual salamanders were 
either flushed downstream or retreated to the subsurface. This site had 
a relatively undeveloped watershed (Bowles et al. 2006, p. 112), 
indicating that the runoff was largely natural and not caused by 
impervious cover.
    In conclusion, flooding is a naturally occurring event that all 
four salamander species have adapted to in the past. Further, even 
though flooding is a factor that seems to be impacting all four 
salamanders' surface habitats, we do not believe it is occurring at a 
scale that would cause the extinction of any of the salamanders on its 
own. Because of this, we consider flooding on its own to have a limited 
effect on the species and their habitats. However, in combination with 
the other threats identified in this five-factor analysis, we think 
flooding may be contributing to the species' risk of extinction by 
reducing its long-term viability. The intensity of flooding events has 
increased due to increases in impervious cover. As previously noted, 
once natural vegetation in a watershed is replaced with impervious 
cover, rainfall is converted to surface runoff instead of filtering 
through the ground (Schueler 1991, p. 114). Impervious cover in a 
stream's watershed causes streamflow to shift from predominately 
baseflow, which is derived from natural filtration processes and 
discharges from local groundwater supplies, to predominately stormwater 
runoff. With increasing stormwater runoff, the amount of baseflow 
available to sustain water supplies during drought cycles is diminished 
and the frequency and severity of flooding increases. Because of the 
detrimental effects previously discussed in association with increased 
stormwater runoff, we consider changes in flow regime due to impervious 
cover to be an ongoing threat to all four central Texas salamanders' 
surface habitats.

Climate Change

    Future climate change could potentially affect water quantity and 
spring flow for the four salamander species. According to the 
Intergovernmental Panel on Climate Change (IPCC 2007, p. 1), ``warming 
of the climate system is unequivocal, as is now evident from 
observations of increases in global averages of air and ocean 
temperatures, widespread melting of snow and ice, and rising global 
average sea level.'' Localized projections suggest the southwest United 
States may experience the greatest temperature increase of any area in 
the lower 48 States (IPCC 2007, p. 8), with warming increases in 
southwestern States greatest in the summer. The IPCC also predicts hot 
extremes, heat waves, and heavy precipitation will increase in 
frequency (IPCC 2007, p. 8).
    Climate change could compound the threat of decreased water 
quantity at salamander spring sites. An increased risk of drought could 
occur if evaporation exceeds precipitation levels in a particular 
region due to increased greenhouse gases in the atmosphere (CH2M HILL 
2007, p. 18). The Edwards Aquifer is also predicted to experience 
additional stress from climate change that could lead to decreased 
recharge and low or ceased springflows given increasing pumping demands 
(Lo[aacute]iciga et al. 2000, pp. 192-193). CH2M HILL (2007, pp. 22-23) 
identified possible effects of climate change on water resources within 
the Lower Colorado River Watershed (which contributes recharge to 
Barton Springs). A reduction of recharge to aquifers and a greater 
likelihood for more extreme droughts were identified as potential 
impacts to water resources (CH2M HILL 2007, p. 23). The droughts of 
2008 to 2009, and 2010 to 2011, were two of the worst in central Texas 
history, with the period from October 2010, through September 2011, 
being the driest 12-month period in Texas since rainfall records began 
(LCRA 2011, p. 1). Rainfall in early 2012 has lessened the intensity of 
the current drought, but below average rainfall and above average 
temperatures are forecasted for the summer of 2012 (LCRA 2012, p. 1).
    In summary, the effects of climate change could potentially lead to 
detrimental impacts on aquifer-dependent species, especially coupled 
with other threats on water quality and quantity. However, there are 
little data available to correlate groundwater trends and climate 
change, and groundwater typically represents an integration of past 
climatic conditions over many years due to its time within an aquifer 
system (Mace and Wade 2008, p. 657). Recharge, pumping, natural 
discharge, and saline intrusion of groundwater systems could all be 
affected by climate change (Mace and Wade 2008, p. 657). Because 
climate change has the potential to negatively affect water quality and 
spring flow, we consider climate change to be a potential threat to all 
four central Texas salamanders and their habitats, now and in the 
future.

Land Conservation Programs and Plans

    The Williamson County Conservation Foundation (Foundation), a 
nonprofit organization established by Williamson County in 2002, is 
currently working to find ways to conserve endangered species and other 
unlisted species of concern in Williamson County, Texas. This 
organization held a Georgetown salamander workshop in November 2003, in 
an effort to bring together landowners, ranchers, farmers, developers, 
local and State officials, Federal agencies, and biologists to discuss 
information currently known about the Georgetown salamander and to 
educate the public on the threats faced by this species.
    With the help of a grant funded through section 6 of the Act, the 
Foundation developed the Williamson County Regional HCP to obtain a 
section 10(a)(1)(B) permit for incidental take of federally listed 
endangered species in Williamson County, Texas. This HCP became final 
in October 2008. Although the Georgetown salamander is not currently 
listed and is not a ``covered'' species, the Foundation has included 
considerations for the Georgetown salamander in the HCP. In particular, 
they plan to conduct a status review of the Georgetown salamander. The 
Foundation plans to fund at least $50,000 per year for 5 years for 
monitoring, surveying, and gathering baseline data on water quality and 
quantity at salamander spring sites. Information gathered during this 
status review will be used to develop a conservation strategy for this 
species. The Foundation began allocating funding for Georgetown 
salamander research and monitoring beginning in 2010. A portion of that 
funding supported mark-recapture studies of the Georgetown salamander 
at two of its

[[Page 50790]]

known localities (Twin Springs and Swinbank Spring) in 2010 and 2011 
(Pierce 2011a, p. 20). Additional funds have been directed at water 
quality assessments of at least two known localities and efforts to 
find previously undiscovered Georgetown salamander populations (Boyd 
2011, pers. comm.). Although Jollyville Plateau salamanders are present 
in southwest Williamson County and Salado salamander spring sites are 
likely influenced by the Edwards Aquifer Recharge Zone in northern 
Williamson County, the regional HCP does not include considerations for 
these species. Also, Austin blind salamanders are not affected by this 
HCP.
    Although the Service worked with the Foundation to develop the 
regional HCP for several listed karst invertebrates, it is also 
expected to benefit the Georgetown salamander by lessening the 
potential for water quality degradation within the spring systems it 
inhabits. As part of this HCP, the Foundation is looking to set aside 
land that is beneficial to karst invertebrate species. Some of these 
lands are in areas that will also provide water quality benefits for 
the Georgetown salamander. For example, the Foundation has purchased an 
easement on the 64.4-ac (26.1-ha) Lyda tract (Cobbs Cavern) in 
Williamson County through the section 6 grant program. This section 6 
grant was awarded for the protection of listed karst invertebrate 
species; however, protecting this land also benefited the Georgetown 
salamander. Although the spring where salamanders are located was not 
included in the easement, a portion of the contributing watershed for 
this spring was included. For this reason, some water quality benefits 
to the salamander are expected. In January 2008, the Foundation also 
purchased the 145-ac (59-ha) Twin Springs preserve area. This tract is 
one of the sites known to be occupied by Georgetown salamanders.
    Despite the conservation efforts of the Foundation, the Georgetown 
salamander faces ongoing threats due to the lack of habitat protection 
outside of these preserves. This species is limited to 16 known 
localities, of which only three (Cobbs Spring, Cobbs Well, and Twin 
Springs) have some amount of protection by the Foundation. The 
population size of Georgetown salamanders at Cobbs Spring is unknown, 
while the population size at Twin Springs is estimated to be only 100 
to 200 individuals (Pierce 2011a, p. 18). Furthermore, the watershed of 
Cobbs Spring is currently only partially protected by the Foundation.
    The Balcones Canyonlands Preserve offers some water quality 
benefits to the Jollyville Plateau salamander in portions of the Bull 
Creek, Brushy Creek, Cypress Creek, and Long Hollow Creek drainages 
through preservation of open space (Service 1996a, pp. 2-28, 2-29). 
However, eight of the nine City of Austin monitoring sites occupied by 
the Jollyville Plateau salamander within the Balcones Canyonlands 
Preserve have experienced water quality degradation occurring upstream 
and outside of the preserved tracts (O'Donnell et al. 2006, pp. 29, 34, 
37, 49; COA 1999, pp. 6-11; Travis County 2007, p. 4). Additionally, 
Jollyville Plateau salamanders are not a covered species under the 
section 10(a)(1)(B) permit under which the preserves were established 
(Service 1996b, pp. 1-10). Therefore, they receive no specific 
protections under the Balcones Canyonlands Preserve permit, such as 
mitigation to offset impacts from development.
    The landowners of one 8,126-ac (3,288-ha) property with at least 
three high-quality Salado salamander sites and the landowner of another 
property with one Salado salamander site have shown a commitment to 
natural resource conservation and land stewardship practices that 
benefit the Salado salamander. Neither ranch owner has immediate plans 
to develop their land, which means that the Salado salamander is 
currently not faced with threats from urbanization (see discussion 
above under Factor A) from these lands. However, only 21 percent of the 
watershed is contained within the property with three Salado salamander 
sites, and only 3 percent of the watershed is contained within the 
other property with the one Salado salamander site. The remaining area 
of the watersheds and the recharge zone for these springs is not 
contained within the properties and is not protected from future 
development. Considering the projected growth rates expected in Bell 
County (from 237,974 in 2000, to 397,741 in 2040, a 67 percent increase 
over the 40-year period; Texas State Data Center 2009, p. 19), these 
Salado salamander spring sites are still at threat from the detrimental 
effects of urbanization. The threat of development and urbanization 
continues into the foreseeable future because there are no long-term, 
binding conservation plans in place for these properties or adequate 
regulations in place for the watersheds or recharge zone.
    The City of Austin is implementing an HCP to avoid, minimize, and 
mitigate incidental take of the Barton Springs salamander resulting 
from the continued operation and maintenance of Barton Springs Pool and 
adjacent springs (City of Austin 1998, pp. 1-53). Many of the 
provisions of the plan also benefit the Austin blind salamander. These 
provisions include: (1) Training lifeguard and maintenance staff to 
protect salamander habitat, (2) controlling erosion and preventing 
surface runoff from entering the springs, (3) ecological enhancement 
and restoration, (4) monthly monitoring of salamander numbers, (5) 
public outreach and education, and (6) establishment and maintenance of 
a captive breeding program, which includes the Austin blind salamander. 
As part of this HCP, the City of Austin completed habitat restoration 
of Eliza Spring and the main pool of Barton Springs in 2003 and 2004. A 
more natural flow regime was reconstructed in these habitats by 
removing large obstructions to flow.

Conclusion of Factor A

    Degradation of habitat, in the form of reduced water quality and 
quantity and disturbance of spring sites (surface habitat), is the 
primary threat to the Austin blind, Jollyville Plateau, Georgetown, and 
Salado salamanders. Reductions in water quality occur primarily as a 
result of urbanization, which increases the amount of impervious cover 
in the watershed. Impervious cover increases storm flow velocities and 
increases erosion and sedimentation. Impervious cover also changes 
natural flow regimes within watersheds and increases the transport of 
contaminants common in urban environments, such as oils, metals, and 
pesticides.
    After identifying 15 watersheds within the Watershed Boundary 
Dataset as being occupied by 1 of the 4 central Texas salamander 
species, and using the most recent National Land Cover Dataset 
impervious cover data available (from 2006), we could draw some 
generalizations about how each watershed might be affected by 
development. The watershed where the Austin blind salamander is known 
to occur has an average overall impervious cover estimate of 12 
percent, but also includes some Balcones Canyonlands Preserve lands. 
Although this managed open space likely contributes some water quality 
benefits to surface flow, the habitat of this largely subterranean 
species can be influenced by land use throughout the recharge zone of 
the aquifer that supplies its spring flow.
    The watersheds within the Jollyville Plateau salamander's range 
have average impervious cover estimates that range from approximately 6 
percent to 34 percent. Although the Balcones

[[Page 50791]]

Canyonlands Preserve and other lands managed for open space within 
these watersheds likely provide some water quality benefits for this 
species, five out of the six watersheds that occur within its range 
have overall impervious cover estimates that can lead to sharp declines 
in water quality or cause permanent conditions of poor water quality 
(Schueler 1994, pp. 100-102).
    The watersheds within the Georgetown salamander's range have 
average impervious cover estimates that range from approximately 0.59 
percent to 10 percent. Five out of the six watersheds within this 
species' range are well below impervious cover levels that can lead to 
declines in water quality. With only two large tracts of land managed 
specifically as open space (64 ac (26 ha) and 145 ac (59 ha)) within 
the Georgetown salamander's range, it is likely that water quality for 
this species' habitat will decline into the future as impervious cover 
increases with development.
    The two watersheds within the Salado salamander's range have 
average impervious cover estimates of 0.31 percent and 0.91 percent. 
Although four known Salado salamander sites are located on large, 
undeveloped ranches (8,126 ac (3,288 ha) and 827 ac (335 ha)), a 
significant portion of the recharge zone for the Northern Segment of 
the Edwards Aquifer that supplies water to this species' habitat 
extends to areas outside of these properties. Furthermore, we could not 
identify any large tracts managed specifically as open space within the 
Salado salamander's range. We also could identify no agreements in 
place to preserve or manage any properties for the benefit of this 
species or its habitat. Without these, it is likely that water quality 
within the Salado salamander's habitat will decrease as development and 
impervious cover increases in these watersheds in the future.
    Expanding urbanization results in an increase of contaminants, such 
as fertilizers and pesticides, within the watershed, which degrades 
water quality at salamander spring sites. Additionally, urbanization 
increases nutrient loads at spring sites, which can lead to decreases 
in dissolved oxygen levels. Construction activities are a threat to 
both water quality and quantity because they can increase sedimentation 
and dewater springs by intercepting aquifer conduits.
    Various other threats exist for these species, as well. Drought, 
which may be compounded by the effects of global climate change, also 
degrades water quality and reduces available habitat for the 
salamanders. Water quantity can also be reduced by groundwater pumping. 
Flood events contribute to the salamanders' risks of extinction by 
degrading water quality through increased sedimentation and 
contaminants levels, which may damage or alter substrates. Impoundments 
are also a threat for all four central Texas salamanders. Feral hogs 
are a threat to Georgetown, Salado, and Jollyville Plateau salamanders 
because they can physically alter their surface habitat. Likewise, 
livestock are a threat to Georgetown and Salado salamanders' surface 
habitat. Additionally, catastrophic spills and leaks remain a threat 
for many salamander locations. All of these threats are predicted to 
increase in the future, as the human population and development 
increases within watersheds that provide habitat for these salamanders. 
Overall, we consider the combined threats of Factor A to be ongoing and 
with a high degree of impact to all four central Texas salamanders and 
their habitats.

Factor B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    There is no available information regarding overutilization of any 
of the four salamander species for commercial, recreational, 
scientific, or educational purposes. We do not consider overutilization 
to be a threat to the four central Texas salamander species now or in 
the future.

Factor C. Disease or Predation

    Chytridiomycosis (chytrid fungus) is a fungal disease that is 
responsible for killing amphibians worldwide (Daszak et al. 2000, p. 
445). The chytrid fungus has been documented on the feet of Jollyville 
Plateau salamanders from 15 different sites and on Austin blind 
salamanders in the wild (O'Donnell et al. 2006, pp. 22-23; Chamberlain 
2011, City of Austin, pers. comm.). However, the salamanders are not 
displaying signs of infection (O'Donnell et al. 2006, p. 23). We have 
no data to indicate whether impacts from this disease may increase or 
decrease in the future, and therefore, whether this disease is a 
significant factor affecting the species (a threat). Therefore, we do 
not consider chytridiomycosis to be a threat to any of the four central 
Texas salamanders at this time.
    However, a condition affecting Barton Springs salamanders may also 
be a threat to the Austin blind salamander. In 2002, 19 Barton Springs 
salamanders, which co-occur with the Austin blind salamander, were 
found at Barton Springs with bubbles of gas occurring throughout their 
bodies (Chamberlain and O'Donnell 2003, p. 17). Three similarly 
affected Barton Springs salamanders also were found in 2003 
(Chamberlain, unpublished data). Of the 19 salamanders affected in 
2002, 12 were found dead or died shortly after they were found. Both 
adult and juvenile Barton Springs salamanders have been affected 
(Chamberlain and O'Donnell 2003, pp. 10, 17).
    The incidence of gas bubbles in salamanders at Barton Springs is 
consistent with a disorder known as gas bubble disease, or gas bubble 
trauma, as described by Weitkamp and Katz (1980, pp. 664-671). In 
animals with gas bubble trauma, bubbles below the surface of the body 
and inside the cardiovascular system produce lesions and dead tissue 
that can lead to secondary infections (Weitkamp and Katz 1980, p. 670). 
Death from gas bubble trauma is apparently related to an accumulation 
of internal bubbles in the cardiovascular system (Weitkamp and Katz 
1980, p. 668). Pathology reports on affected animals at Barton Springs 
found that the symptoms were consistent with gas bubble trauma 
(Chamberlain 2011, pers. comm.). The cause of gas bubble trauma is 
unknown, but its incidence has been correlated with water temperature. 
Gas bubble trauma has been observed in Austin blind salamanders in 
captivity when exposed to water temperatures approaching 80 [deg]F 
(26.7 [deg]C) (Chamberlain 2011, pers. comm.).
    We consider gas bubble trauma to be a threat with a limited impact 
to the Austin blind salamander now and in the future. To our knowledge, 
gas bubble trauma has not been observed in Jollyville Plateau, 
Georgetown, or Salado salamanders. However, if an increase in water 
temperature is a causative factor, these three species may also be at 
risk during droughts or other environmental stressors that result in 
increases in water temperature. However, at this time, we do not 
consider gas bubble trauma to be a threat to the Jollyville Plateau, 
Georgetown, or Salado salamanders.
    Regarding predation, City of Austin biologists found Jollyville 
Plateau salamander abundances were negatively correlated with the 
abundance of predatory centrarchid fish (carnivorous freshwater fish 
belonging to the sunfish family), such as black bass (Micropterus spp.) 
and sunfish (Lepomis spp.) (COA 2001, p. 102). Predation of a 
Jollyville Plateau salamander by a centrarchid fish was observed during 
a May 2006 field survey (O'Donnell et al. 2006, p. 38). However, Bowles 
et al. (2006, pp. 117-118) rarely observed these predators in 
Jollyville Plateau salamander habitat.

[[Page 50792]]

Centrarchid fish are currently present in two of three Austin blind 
salamander sites (Laurie Dries, City of Austin, unpublished data), and 
crayfish (another predator) occupy much of the same habitat as 
Georgetown, Salado, and Jollyville Plateau salamanders. All four 
salamanders have been observed retreating into gravel substrate after 
cover was moved, suggesting these salamanders display anti-predation 
behavior (Bowles et al. 2006, p. 117). However, we do not have enough 
data to indicate whether predation of the four salamander species may 
increase in the future or is a significant factor affecting the species 
and therefore a threat. Therefore, we do not consider predation to be a 
threat to any of the four central Texas salamanders at this time.
    In summary, while predation and disease may be affecting 
individuals of these salamander species, we believe that these are not 
significant factors affecting the species' continued existence. Neither 
predation nor disease is occurring at a level that we consider to be a 
threat to the continued existence of any of the four central Texas 
salamander species now or in the future.

Factor D. The Inadequacy of Existing Regulatory Mechanisms

Water Quantity and Quality Protections
    The main threats to the Austin blind, Jollyville Plateau, 
Georgetown, and Salado salamanders are from habitat degradation, 
specifically a lowering of water quality and quantity. Therefore, 
regulatory mechanisms that protect water from the Edwards Aquifer are 
crucial to the future survival of the species. These four salamander 
species are not listed on the Texas State List of Endangered or 
Threatened Species (TPWD 2011b, pp. 2-3). Therefore, these species are 
receiving no direct protection from the State.
    Under authority of the Texas Administrative Code (Title 30, Chapter 
213), the Texas Commission on Environmental Quality (TCEQ) regulates 
activities having the potential for polluting the Edwards Aquifer and 
hydrologically connected surface streams. Among other State statutes 
designed to protect water quality, the Edwards Rules require a number 
of water quality protection measures for new development occurring in 
the recharge and contributing zones of the Edwards Aquifer. These 
regulations provide incentives to developers in the form of exemptions 
and exceptions from permanent water quality control mechanisms for 
developments with less than 20 percent impervious cover. However, only 
the Georgetown salamander sites and about half of the known Jollyville 
Plateau salamander locations occur within those portions of the Edwards 
Aquifer regulated by TCEQ. Furthermore, the jurisdiction of the Edwards 
Rules does not extend into Bell County or the Barton Springs Segment 
(TCEQ 2001, p. 1). Therefore, many salamander populations do not 
directly benefit from these protections.
    We recognize that implementation of the Edwards Rules in other 
areas of the Northern Segment of the Edwards Aquifer may have the 
potential to affect conditions at spring sites occupied by the Salado 
salamander. For those salamander locations that are covered by the TCEQ 
regulations, the regulations do not address land use, impervious cover 
limitations, non-point source pollution, or application of fertilizers 
and pesticides over the recharge zone (30 TAC 213.3). We are unaware of 
any water quality ordinances more restrictive than TCEQ's Edwards Rules 
in Bell, Williamson, or Travis Counties outside the City of Austin.
    The City of Austin's water quality ordinances (City of Austin Code, 
Title 25, Chapter 8) provide some water quality regulatory protection 
to the Austin blind and Jollyville Plateau salamanders' habitat within 
Travis County. The ordinances range from relatively strict controls in 
its extraterritorial jurisdiction to lesser controls in outlying areas. 
Some of the protections provided in these ordinances include riparian 
buffers, permanent water quality control structures, wastewater system 
restrictions, and impervious cover limitations (Turner 2007, pp. 1-2). 
Some studies have demonstrated that these ordinances play a role in 
protecting Austin-area surface waters from urbanization-related 
contaminants. For example, in the period after the City of Austin 
passed water quality ordinances in 1986 and 1991, sedimentation and 
nutrients decreased in the five major Austin-area creeks (Turner 2007, 
p. 7). Peak storm flows were also lower after the enactment of the 
ordinances, which may explain the decrease in sedimentation (Turner 
2007, p. 10). Likewise, a separate study on the water quality of Walnut 
Creek (Jollyville Plateau salamander habitat) from 1996 to 2008 found 
that water quality has either remained the same or improved (Scoggins 
2010, p. 15). These trends in water quality occurred despite a drastic 
increase in construction and impervious cover during the same time 
period (Turner 2007, pp. 7-8; Scoggins 2010, p. 4), indicating that the 
ordinances are effective at mitigating some of the impacts of 
development on water quality. Another study in the Austin area compared 
18 sites with stormwater controls (retention ponds) in their watersheds 
to 20 sites without stormwater controls (Maxted and Scoggins 2004, p. 
8). In sites with more than 40 percent impervious cover, more 
contaminant-sensitive macroinvertebrate species were found at sites 
with stormwater controls than at sites without controls (Maxted and 
Scoggins 2004, p. 11).
    However, based on long-term monitoring that shows an overall water 
quality decline at Jollyville Plateau and Austin blind salamander 
sites, these local ordinances are not effective at reducing contaminant 
levels to the extent that they no longer threaten salamander habitat 
(see discussion under Factor A). Furthermore, it is unclear how much 
surface water quality controls in developed areas benefit groundwater 
quality. A City of Austin study of four Jollyville Plateau salamander 
spring sites within two subdivisions found that stricter water quality 
controls (wet ponds instead of standard sedimentation/filtration ponds) 
did not translate into improved groundwater quality (Herrington et al. 
2007, pp. 13-14).
    In addition, Title 7, Chapter 245 of the Texas Local Government 
Code permits ``grandfathering'' of certain local regulations. 
Grandfathering allows developments to be exempted from new requirements 
for water quality controls and impervious cover limits if the 
developments were planned prior to the implementation of such 
regulations. However, these developments are still obligated to comply 
with regulations that were applicable at the time when project 
applications for development were first filed (Title 7, Chapter 245 of 
the Texas Local Government Code p. 1). Unpublished data provided by the 
City of Austin (2007) indicates that up to 26 percent of undeveloped 
areas within watersheds draining to Jollyville Plateau salamander 
habitat may be exempted from current water quality control requirements 
due to ``grandfathering'' legislation.
    On January 1, 2006, the City of Austin banned the use of coal tar 
sealant (Scoggins et al. 2009, p. 4909), which has been shown to be the 
main source of PAHs in Austin-area streams (Mahler et al. 2005, p. 
5565). However, historically applied coal tar sealant lasts for several 
years and can remain a source of PAHs to aquatic systems (DeMott et al. 
2010, p. 372). A study that examined PAH concentrations in Austin 
streams before the ban and 2 years after the ban found no difference, 
indicating

[[Page 50793]]

that either more time is needed to see the impact of the coal tar ban, 
or that other sources (e.g. airborne and automotive) are contributing 
more to PAH loadings (DeMott et al. 2010, pp. 375-377). Furthermore, 
coal tar sealant is still legal outside of the City of Austin's 
jurisdiction and may be contributing PAH loads to northern Jollyville 
Plateau, Georgetown, and Salado salamander habitat.
    The TCEQ has required wastewater treatment systems within the 
Barton Springs Edwards Aquifer recharge and contributing zones to 
obtain a Texas Land Application Permit (TLAP) in order to discharge 
effluent onto the land (Ross 2011, p. 7). Although these permits are 
designed to protect the surface waters and underground aquifer, studies 
have demonstrated reduced water quality downstream of TLAP sites (Ross 
2011, pp. 11-18). Ross (2011, pp. 18-21) attributes this regulatory 
inadequacy to TCEQ's failure to conduct regular soil monitoring for 
nutrient accumulation on TLAP sites, and the failure to conduct indepth 
reviews of TLAP applications.
    The TCEQ has developed voluntary water quality protection measures 
for developers to minimize water quality effects to springs systems and 
other aquatic habitats within the Edwards Aquifer region of Texas (TCEQ 
2005, p. i). In February 2005, the Service concurred that these 
measures, if implemented, would protect several aquatic species from 
take, including the Georgetown salamander, due to water quality 
degradation resulting from development in the Edwards Aquifer region 
(TCEQ 2007, p. 1). However, it should be noted that as non-listed 
species, ``take'' prohibitions do not apply. Thus, these water quality 
protection measures are not a regulatory mechanism.
    The Barton Springs Edwards Aquifer Conservation District permits 
and regulates most wells on the Barton Springs segment of the Edwards 
Aquifer, subject to the limits of the State law. Bell County's 
groundwater resources are currently managed by the Clearwater 
Underground Water Conservation District. There are no groundwater 
conservation districts in Williamson or northern Travis Counties, so 
groundwater pumping is unregulated in these areas (TPWD 2011a, p. 7).
Conclusion of Factor D
    Data indicate that water quality degradation in sites occupied by 
Austin blind and Jollyville Plateau salamanders continues to occur 
despite the existence of current regulatory mechanisms in place to 
protect water quality (Turner 2005a, pp. 8-17, O'Donnell et al. 2006, 
p. 29). Long-term water quality data are not available for Georgetown 
and Salado salamander sites, but rapid human population growth and 
urbanization in Williamson and Bell Counties continues. Existing 
regulations in these counties do not address many of the sources of 
groundwater pollution that are typically associated with urbanized 
areas. Therefore, we consider the inadequacy of existing regulatory 
mechanisms to be an ongoing, significant threat to all four salamander 
species now and in the foreseeable future.

Factor E. Other Natural or Manmade Factors Affecting Its Continued 
Existence

Ultraviolet Radiation
    Increased levels of ultraviolet-B (UV-B) radiation, due to 
depletion of the stratospheric ozone layers, may lead to declines in 
amphibian populations (Blaustein and Kiesecker 2002, pp. 598-600). For 
example, research has demonstrated that UV-B radiation causes 
significant mortality and deformities in developing long-toed 
salamanders (Ambystoma macrodactylum) (Blaustein et al. 1997, p. 
13,735). Exposure to UV-B radiation reduces growth in clawed frogs 
(Xenopus laevis) (Hatch and Burton, 1998, p. 1,783) and lowers hatching 
success in Cascades frogs (Rana cascadae) and western toads (Bufo 
boreas) (Kiesecker and Blaustein 1995, pp. 11,050-11,051). In lab 
experiments with spotted salamanders, UV-B radiation diminished their 
swimming ability (Bommarito et al. 2010, p. 1151). Additionally, UV-B 
radiation may act synergistically (the total effect is greater than the 
sum of the individual effects) with other factors (for example, 
contaminants, pH, pathogens) to cause declines in amphibians (Alford 
and Richards 1999, p. 141; see Synergistic and Additive Interactions 
among Stressors). Some researchers believe that future increases in UV-
B radiation will have significant detrimental impacts on amphibians 
that are sensitive to this radiation (Blaustein and Belden 2003, p. 
95).
    The effect of increased UV-B radiation on the Austin blind, 
Jollyville Plateau, Georgetown, and Salado salamanders is unknown. 
These species may be protected from UV-B radiation through shading from 
trees at some spring sites. Removal of natural riparian vegetation may 
put these species at risk. Because eggs are believed to be deposited 
underground (Bendik 2011b, pers. comm.), UV-B radiation may have no 
impact on the hatching success of these species. In conclusion, the 
effect of increased UV-B radiation has the potential to cause 
deformities or developmental problems to individuals, but we do not 
consider this stressor to significantly contribute to the risk of 
extinction of any of the four central Texas salamander species at this 
time.
Deformities in Jollyville Plateau Salamanders
    Jollyville Plateau salamanders observed at the Stillhouse Hollow 
monitoring sites have shown high incidences of deformities, such as 
curved spines, missing eyes, missing limbs or digits, and eye injuries 
(O'Donnell et al. 2006, p. 26). The Stillhouse Hollow location was also 
cited as having the highest observation of dead Jollyville Plateau 
salamanders (COA 2001, p. 88). Although water quality is relatively low 
in the Stillhouse Hollow drainage (O'Donnell et al. 2006, pp. 26, 37), 
no statistical correlations were found between the number of 
deformities and nitrate concentrations (O'Donnell et al. 2006, p. 26). 
Environmental toxins are the suspected cause of salamander deformities 
(O'Donnell et al. 2006, p. 25; COA 2001, pp. 70-74), but deformities in 
amphibians can also be the result of genetic mutations, parasitic 
infections, UV-B radiation, or the lack of an essential nutrient. More 
research is needed to elucidate the cause of these deformities. We 
consider deformities to be a stressor of low level impact to the 
Jollyville Plateau salamander because this stressor is only an issue at 
one site and it does not appear to be an issue for the other salamander 
species.
Small Population Size and Stochastic Events
    All four central Texas salamanders may be more susceptible to 
threats and impacts from stochastic events because of their small 
population sizes. The risk of extinction for any species is known to be 
highly indirectly correlated with population size (Ogrady et al. 2004, 
pp. 516, 518; Pimm et al. 1988, pp. 774-775). In other words, the 
smaller the population, the greater the overall risk of extinction. 
True population size estimates have not been generated at most sites 
for these species, but mark-recapture studies at some of the highest 
quality sites for Georgetown and Jollyville Plateau salamanders 
estimated populations as low as 78 (O'Donnell et al. 2008, pp. 44-45). 
Populations are likely smaller at lower quality sites. Small population 
sizes can also act synergistically with other traits (such as being a 
habitat specialist and having

[[Page 50794]]

limited distribution, as is the case with the four salamander species) 
to greatly increase risk of extinction (Davies et al. 2004, p. 270). 
Stochastic events from either environmental factors (random events such 
as severe weather) or demographic factors (random causes of births and 
deaths of individuals) may also heighten other threats to the 
salamanders because of the limited range and small population sizes 
(Melbourne and Hastings 2008, p. 100).
    The highly restricted ranges of the salamanders and entirely 
aquatic environment make them extremely vulnerable to threats such as 
decreases in water quality and quantity. This is especially true for 
the Austin blind salamander, which is found in only one locality 
comprised of three hydrologically connected springs of Barton Springs, 
and the Salado salamander, which has only been found at seven spring 
sites. Due to their very limited distribution, the Austin blind and 
Salado salamanders are especially sensitive to incidences such as storm 
events, which can dramatically affect dissolved oxygen levels and 
increase contaminants, and cause catastrophic spills and leaks. One 
catastrophic spill event in Barton Springs could potentially cause the 
extinction of the Austin blind salamander in the wild.
    The presence of several populations of Jollyville Plateau and 
Georgetown salamanders does provide some possibility for natural 
recolonization for these species if any of these factors resulted in a 
local extirpation event (Fagan et al. 2002, p. 3,255). In conclusion, 
we do not consider small population size to be a threat in and of 
itself to any of the four salamander species, but their small 
population sizes may make them more vulnerable to extinction from other 
existing or potential threats, such as a major stochastic event. 
Therefore, the magnitude of a stochastic event affecting the continued 
existence of the Jollyville Plateau and Georgetown salamanders is 
moderate because these species have more populations over a broader 
range. On the other hand, recolonization following a stochastic event 
is less likely for Austin blind and Salado salamanders due to a fewer 
number of known sites. Therefore, the impacts from a stochastic event 
for the Austin blind and Salado salamanders is a significant threat.
Synergistic and Additive Interactions Among Stressors
    The interactions among multiple stressors (for example, 
contaminants, UV-B radiation, pathogens) may be contributing to 
amphibian population declines (Blaustein and Kiesecker 2002, p. 598). 
Multiple stressors may act additively or synergistically to have 
greater detrimental impacts on amphibians compared to a single stressor 
alone. Kiesecker and Blaustein (1995, p. 11,051) found a synergistic 
effect between UV-B radiation and a pathogen in Cascades frogs and 
western toads. Researchers demonstrated that reduced pH levels and 
increased levels of UV-B radiation independently had no effect on 
leopard frog (Rana pipiens) larvae; however, when combined, these two 
caused significant mortality (Long et al. 1995, p. 1,302). 
Additionally, researchers demonstrated that UV-B radiation increases 
the toxicity of PAHs, which can cause mortality and deformities on 
developing amphibians (Hatch and Burton 199, pp. 1,780-1,783). Beattie 
et al. (1992, p. 566) demonstrated that aluminum becomes toxic to 
amphibians at low pH levels. Also, disease outbreaks may occur only 
when there are contaminants or other stressors in the environment that 
reduce immunity (Alford and Richards 1999, p. 141). For example, 
Christin et al. (2003, pp. 1,129-1,130, 1,132) demonstrated that 
mixtures of pesticides reduced the immunity to parasitic infections in 
leopard frogs.
    The effect of synergistic effects between stressors on the Austin 
blind, Jollyville Plateau, Georgetown, and Salado salamanders is not 
currently known. Furthermore, different species of amphibians differ in 
their reactions to stressors and combinations of stressors (Kiesecker 
and Blaustein 1995, p. 11,051; Relyea et al. 2009, pp. 367-368; Rohr et 
al. 2003, pp. 2,387-2,390). Studies that examine the effects of 
interactions among multiple stressors on the four central Texas 
salamanders are lacking. However, based on the number of examples in 
other amphibians, the possibility of synergistic effects on the four 
central Texas salamanders cannot be discounted.
Summary of Factor E
    The effect of increased UV-B radiation is an unstudied stressor to 
the four central Texas salamanders that has the potential to cause 
deformities or development problems. The effect of this stressor is 
believed to be low at this time.
    Deformities have been documented in one of the four salamander 
species (Jollyville Plateau salamander), and at only one location 
(Stillhouse Hollow). We do not know what causes these deformities, and 
there is no evidence that the incidence rate is increasing or 
spreading. Therefore, the effect of this stressor is believed to be 
low.
    Small population sizes at most of the sites for the salamanders is 
not a threat in and of itself, but it may increase the risk of local 
extirpation events. However, the Georgetown and Jollyville Plateau 
salamanders may have some ability to recolonize sites because they 
occur in more populations over a broader range. Thus, we consider the 
level of impacts from a stochastic event to be moderate for these two 
species and high for the Austin blind and Salado salamanders due to 
their more limited distributions.
    Finally, the significance of each threat discussed above (under 
Factors A through E) may be influenced by their interactions with other 
threats, and may subsequently increase under certain conditions.

Overall Threat Summary

    The following table provides a general overview of the type, 
anticipated level of impact, and timing of threats facing the four 
salamanders proposed for listing. It is intended to assist the public 
in comparing the threats discussed above among the salamander species. 
The magnitude of threat is defined in terms of scope (the relative 
proportion or range of the species that is affected by the threat) and 
severity (impacts on the overall species' status), such that a high 
magnitude of threat indicates that the species is facing the greatest 
threats to their continued existence (48 FR 43098; September 21, 1983). 
We define imminence as the timing of when a threat begins. A threat is 
considered imminent if it is impacting the species now rather than in 
the foreseeable future. Some of the threats outlined within Tables 3 
through 6 are difficult to fully quantify due to lack of available 
information. These threats were designated an unknown magnitude.

                           Table 3--Summary of Threats to the Austin Blind Salamander
----------------------------------------------------------------------------------------------------------------
                                                                     Level of impact  (low,
               Factor                        Type of threat              medium, high)             Ongoing?
----------------------------------------------------------------------------------------------------------------
A...................................  Contaminants from stormwater  High...................  Yes.
                                       runoff.

[[Page 50795]]

 
                                      Sedimentation from            High...................  Yes.
                                       stormwater runoff.
                                      Changes in flow regime from   Med....................  Yes.
                                       impervious cover.
                                      Excess nutrient input.......  Low....................  Yes.
                                      Pesticides..................  Low....................  Yes.
                                      Catastrophic hazardous        High...................  Yes.
                                       material spills.
                                      Pollution from construction   Med....................  Yes.
                                       activities.
                                      Construction of pipelines...  Low....................  No.
                                      Groundwater pumping.........  Med....................  Yes.
                                      Impoundments................  High...................  Yes.
                                      Physical modification of      Med....................  Yes.
                                       surface habitat for human-
                                       related activities.
                                      Drought.....................  Low....................  Yes.
                                      Flooding....................  Low....................  Yes.
                                      Climate change..............  Unknown................  Yes.
C...................................  Gas bubble trauma...........  Low....................  No.
D...................................  Inadequacy of existing        High...................  Yes.
                                       regulatory mechanisms.
E...................................  Small population size and     High...................  Yes.
                                       stochastic events.
                                      Synergistic and additive      Unknown................  Unknown.
                                       interactions among
                                       stressors.
                                      UV-B radiation..............  Unknown................  Unknown.
----------------------------------------------------------------------------------------------------------------


                        Table 4--Summary of Threats to the Jollyville Plateau Salamander
----------------------------------------------------------------------------------------------------------------
                                                                     Level of impact  (low,
               Factor                        Type of threat              medium, high)             Ongoing?
----------------------------------------------------------------------------------------------------------------
A...................................  Contaminants from stormwater  High...................  Yes.
                                       runoff.
                                      Sedimentation from            High...................  Yes.
                                       stormwater runoff.
                                      Changes in flow regime from   Med....................  Yes.
                                       impervious cover.
                                      Excess nutrient input.......  MedLow.................  Yes.
                                      Pesticides..................  Low....................  Yes.
                                      Catastrophic hazardous        Low....................  Yes.
                                       material spills.
                                      Pollution from construction   HighMed................  Yes.
                                       activities.
                                      Construction of pipelines...  Low....................  No.
                                      Construction of the           Low....................  Yes.
                                       Jollyville Transmission
                                       Main.
                                      Rock quarries...............  Low....................  Yes.
                                      Groundwater pumping.........  Med....................  Yes.
                                      Impoundments................  Low....................  Yes.
                                      Feral hogs..................  Low....................  Yes.
                                      Physical modification of      Low....................  Yes.
                                       surface habitat for human-
                                       related activities.
                                      Drought.....................  MedLow.................  Yes.
                                      Flooding....................  Low....................  Yes.
                                      Climate change..............  Unknown................  Yes.
D...................................  Inadequacy of existing        High...................  Yes.
                                       regulatory mechanisms.
E...................................  Small population size and     Med....................  Yes.
                                       stochastic events.
                                      Synergistic and additive      Unknown................  Unknown.
                                       interactions among
                                       stressors.
                                      UV-B radiation..............  Unknown................  Unknown.
----------------------------------------------------------------------------------------------------------------


                            Table 5--Summary of Threats to the Georgetown Salamander
----------------------------------------------------------------------------------------------------------------
                                                                     Level of impact  (low,
               Factor                        Type of threat              medium, high)             Ongoing?
----------------------------------------------------------------------------------------------------------------
A...................................  Contaminants from stormwater  High...................  Yes.
                                       runoff.
                                      Sedimentation from            High...................  Yes.
                                       stormwater runoff.
                                      Changes in flow regime from   Med....................  Yes.
                                       impervious cover.
                                      Excess nutrient input.......  Low....................  Yes.
                                      Pesticides..................  Low....................  Yes.
                                      Catastrophic hazardous        Med....................  Yes.
                                       material spills.
                                      Pollution from construction   Med....................  Yes.
                                       activities.
                                      Construction of pipelines...  Low....................  No.
                                      Rock quarries...............  Low....................  Yes.
                                      Groundwater pumping.........  Med....................  Yes.
                                      Impoundments................  Low....................  Yes.
                                      Feral hogs..................  Low....................  Yes.
                                      Livestock...................  Low....................  Yes.
                                      Physical modification of      Low....................  Yes.
                                       surface habitat for human-
                                       related activities.
                                      Drought.....................  MedLow.................  Yes.
                                      Flooding....................  Low....................  Yes.
                                      Climate change..............  Unknown................  Yes.
D...................................  Inadequacy of existing        High...................  Yes.
                                       regulatory mechanisms.

[[Page 50796]]

 
E...................................  Small population size and     Med....................  Yes.
                                       stochastic events.
                                      Synergistic and additive      Unknown................  Unknown.
                                       interactions among
                                       stressors.
                                      UV-B radiation..............  Unknown................  Unknown.
----------------------------------------------------------------------------------------------------------------


                              Table 6--Summary of Threats to the Salado Salamander
----------------------------------------------------------------------------------------------------------------
                                                                     Level of impact  (low,
               Factor                        Type of threat              medium, high)             Ongoing?
----------------------------------------------------------------------------------------------------------------
A...................................  Contaminants from stormwater  Med....................  Yes.
                                       runoff.
                                      Sedimentation from            Med....................  Yes.
                                       stormwater runoff.
                                      Changes in flow regime from   Low....................  Yes.
                                       impervious cover.
                                      Excess nutrient input.......  Low....................  Yes.
                                      Pesticides..................  Low....................  Yes.
                                      Catastrophic hazardous        High...................  Yes.
                                       material spills.
                                      Pollution from construction   Low....................  Yes.
                                       activities.
                                      Construction of pipelines...  Low....................  No.
                                      Rock quarries...............  Low....................  Yes.
                                      Groundwater pumping.........  Med....................  Yes.
                                      Impoundments................  Low....................  Yes.
                                      Feral hogs..................  Low....................  Yes.
                                      Livestock...................  Low....................  Yes.
                                      Physical modification of      Low....................  Yes.
                                       surface habitat for human-
                                       related activities.
                                      Drought.....................  Low....................  Yes.
                                      Flooding....................  Low....................  Yes.
                                      Climate change..............  Unknown................  Yes.
D...................................  Inadequacy of existing        High...................  Yes.
                                       regulatory mechanisms.
E...................................  Small population size and     High...................  Yes.
                                       stochastic events.
                                      Synergistic and additive      High...................  Yes.
                                       interactions among
                                       stressors.
                                      UV-B radiation..............  Unknown................  Unknown.
----------------------------------------------------------------------------------------------------------------

Proposed Listing Determination

    As previously noted, the magnitude of a threat is defined in terms 
of scope (the relative proportion or range of the species that is 
affected by the threat) and severity (impacts on the overall species' 
status), such that a high magnitude of threat indicates that the 
species is facing the greatest threats to their continued existence (48 
FR 43098; September 21, 1983). We define imminence as the timing of 
when a threat begins. A threat is considered imminent if it is 
impacting the species now rather than in the foreseeable future.

Austin Blind Salamander

    The primary threat to this species is habitat modification (Factor 
A) in the form of reduced flows and degradation of water quality of 
spring habitats as a result of urbanization within the watersheds and 
recharge and contributing zones of the Edwards Aquifer. Substantial 
human population growth (a projected increase of 84 percent from 2000 
to 2040) is ongoing within Travis County, Texas (Texas State Data 
Center 2008, p. 1), the only location where the Austin blind salamander 
is known to occur. This human population growth is likely to result in 
considerable urbanization within the watershed, which would influence 
spring flow and water quality within the salamander's three known sites 
at Barton Springs. Urbanization leads to increases in sedimentation, 
contaminants, and nutrient loads as well as decreases in aquatic 
invertebrates (the salamander's prey base). Significant changes in 
water quality constituents have been reported from analyses conducted 
from within the Austin blind salamander's habitat at Barton Springs 
Pool (COA 1997, pp. 229, 231-232; Mahler and Van Metre 2000, p. 1); 
these changes have been attributed to urbanization within the recharge 
and contributing zones of the Edwards Aquifer (Turner 2005a, p. 6).
    We analyzed the impervious cover estimates of the watershed within 
the Austin blind salamander's range, along with the amount of land 
currently managed as open space that could possibly contribute water 
quality benefits to the salamander's habitats. The watershed where the 
Austin blind salamander is known to occur has an average overall 
impervious cover estimate of 11.58 percent, which is within the range 
in which sharp declines of water quality in aquatic habitats have been 
observed (Schueler 1994, pp. 100-102). Although this watershed has some 
managed open space that likely contributes water quality benefits to 
surface flow, the habitat of this largely subterranean species can be 
influenced by land use throughout the recharge zone of the aquifer that 
supplies its spring flow. In consideration of this information and 
analysis, we believe the threat of habitat modification in the form of 
reduced water quality is ongoing and has a high level of impact 
throughout the Austin blind salamander's range.
    Data indicate that water quality degradation in sites occupied by 
Austin blind salamanders continues to occur despite the existence of 
current regulatory mechanisms in place designed to protect water 
quality (Turner 2005a, pp. 8-17, O'Donnell et al. 2006, p. 29). 
Therefore, we consider the inadequacy of existing regulatory mechanisms 
to protect against water quality degradation (Factor D) to be a 
significant threat.
    The Edwards Aquifer is at risk from a variety of sources of 
pollutants (Ross 2011, p. 4), including hazardous materials that could 
be spilled or leaked, potentially resulting in the contamination of 
both surface and groundwater resources (Service 2005, pp. 1.6-14-1.6-
15). A catastrophic spill

[[Page 50797]]

could occur if a truck transporting hazardous materials overturned and 
spilled its contents over the recharge zone of the aquifer. The Austin 
blind salamander is at considerable risk from hazardous materials 
spills given that it only occurs at three spring sites in one locality 
(Barton Springs). Among other sources, there is the potential for a 
catastrophic gasoline spill in the Barton Springs Segment of the 
Edwards Aquifer from the Longhorn pipeline (EPA 2000, pp. 9-29-9-30). 
There is also potential for hazardous material spills from the multiple 
drinking water lines and sewage pipelines surrounding Barton Springs. 
For these reasons, we believe the threat of habitat modification in the 
form of water quality degradation and contamination from hazardous 
materials spills to be an ongoing threat of high impact to this 
species.
    Construction activities resulting from urban development are a 
threat to both water quality and quantity because they can increase 
sedimentation and dewater springs by intercepting aquifer conduits. 
Austin blind salamander habitat at Barton Springs is under the threat 
of pollutant loading due to its proximity to construction activities 
and its location at the downstream side of the watershed (COA 1997, p. 
237). Given that construction-related sediment loading is already 
occurring within the Austin blind salamander's narrowly restricted 
range, we believe the threat of habitat modification in the form of 
water quality degradation and changes to water flows caused by 
construction activities from urban development to be an ongoing threat 
of medium impact to this species.
    Another potential threat to the Austin blind salamander and its 
habitat is low flow conditions in the aquifer and at Barton Springs. 
Groundwater pumping can cause such conditions and lead to saline water 
encroachments in the aquifer. Water quality in the Barton Springs 
Segment of the Edwards Aquifer has been degraded in the past due to 
saline encroachment (Slade et al. 1986, p. 62). This water quality 
degradation occurred when Barton Springs discharge was less than 30 cfs 
(Slade et al. 1986, p. 64). Reduced groundwater levels could also 
increase the concentration of some pollutants in the aquifer. Average 
flows at Barton Springs have dropped below 17 cfs as recently as mid-
November 2011 (Barton Springs/Edwards Aquifer Conservation District 
2011, p. 1). This saline water encroachment would threaten the 
freshwater biota in the springs and the aquifer, including the Austin 
blind salamander, by dramatically changing the water chemistry (such as 
increasing conductivity).
    In addition to groundwater pumping, low flows in Barton Springs may 
be attributed to ongoing urbanization and recent drought conditions. 
Future climate change could also affect water quantity and spring flow 
for the Austin blind salamander. Climate change could compound the 
threat of decreased water quantity at salamander spring sites. The 
effects of climate change on aquifer-dependant species is difficult to 
assess; however, the Edwards Aquifer is predicted to experience 
additional stress from climate change that could lead to decreased 
recharge and low or ceased spring flows given increasing pumping 
demands (Lo[aacute]iciga et al. 2000, pp. 192-193). In any case, we 
believe habitat modification in the form of water quantity reduction, 
whether reduced spring flows are caused by climate change or are in 
combination with other stressors, to be an ongoing threat of high 
impact to this species.
    The Austin blind salamander is sensitive to direct physical habitat 
modification, such as modification resulting from human recreational 
activities and impoundments. Eliza Spring and Sunken Garden Spring, two 
of the three locations of the Austin blind salamander, also experience 
vandalism, despite the presence of fencing and signage (Dries 2011, 
pers. comm.). The deep water of Barton Springs likely protects the 
Austin blind salamander's surface habitat from damage from frequent 
human recreation.
    All spring sites for the Austin blind salamander (Main, Eliza, and 
Sunken Garden springs) have been impounded for recreational use. While 
the manmade structures help retain water in the spring pools during low 
flows, they have altered the salamander's natural environment. The 
impoundments have changed the Barton Springs ecosystem from a stream-
like system to a more lentic (still water) environment, thereby 
reducing the water system's ability to flush sediments downstream and 
out of salamander habitat. Because of the physical habitat 
modifications that have permanently impacted the Austin blind 
salamander's habitat or are currently ongoing, we consider this threat 
to be ongoing and of high impact to this species.
    Gas bubble trauma has been observed in Austin blind salamanders in 
captivity (Chamberlain 2011, pers. comm.), and has been known to affect 
another salamander species (the Barton Springs salamander) at Barton 
Springs (Chamberlain 2011, pers. comm.). Chytrid fungus has also been 
documented on the feet of Austin blind salamanders in the wild 
(O'Donnell et al. 2006, pp. 22-23). However, we have no data to 
indicate whether disease or predation (Factor C) of any of the 
salamander species proposed for listing is a significant threat facing 
the species. Predation and disease may be affecting these salamander 
species, but there is not enough evidence to consider these factors 
threats. Neither factor is at a level that we consider to be 
threatening the continued existence of the salamander species now or in 
the foreseeable future.
    Other natural or manmade factors (Factor E) affecting the Austin 
blind salamander include UV-B radiation, small population sizes, 
stochastic events, and synergistic and additive interactions among 
stressors. Increased levels of UV-B radiation, due to the depletion of 
stratospheric ozone layers has been shown to cause significant 
mortality and deformities in amphibian species (Blaustein et al. 1997, 
p. 13,735), although the effects of UV-B radiation on this species are 
unknown. Small population sizes may act synergistically with other 
traits of the species (such as its limited distribution) to increase 
its overall risk of extinction (Davies et al. 2004, p. 270). Stochastic 
events, such as severe weather or demographic changes to the 
population, are also heightened threats because of its restricted range 
and small population sizes (Melbourne and Hastings 2008, p. 100). We 
therefore consider this to be an ongoing threat of high impact.
    The population status of Austin blind salamanders is unknown, 
largely because it is rarely seen at the water's surface (Hillis et al. 
2001, p. 267). However, observations of Austin blind salamanders have 
been decreasing in recent years (2009-2010) (COA 2011a, pp. 51-52). 
From January 1998 to December 2000, there were only 17 documented 
observations of the Austin blind salamander (Hillis et al. 2001, p. 
273). The abundance of Austin blind salamanders increased slightly from 
2002 to 2006, but fewer observations have been made in more recent 
years (2009 to 2010) (COA 2011a, pp. 51-52). Because fewer observations 
coincide with habitat degradation throughout the species' entire range, 
we expect the downward trend to continue into the future as human 
population growth and urbanization drive further declines in habitat 
quality and quantity. Due to its small range and probable small 
population size, we believe the species resiliency to the threats 
outlined above is low.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a

[[Page 50798]]

significant portion of its range'' and a threatened species as any 
species ``that is likely to become endangered throughout all or a 
significant portion of its range within the foreseeable future.'' Due 
to small population size, limited range, and susceptibility to ongoing 
threats, we determine that the Austin blind salamander is currently on 
the brink of extinction and therefore meets the definition of 
endangered. We find that the Austin blind salamander is presently in 
danger of extinction throughout its entire range based on the 
immediacy, severity, and scope of the threats described above. The 
Austin blind salamander species is proposed as endangered, rather than 
threatened, because the threats are occurring now, and their impacts to 
the species and its habitat would be catastrophic given the very 
limited range of the species, making the salamander at risk of 
extinction at the present time. Therefore, on the basis of the best 
available scientific and commercial information, we propose listing the 
Austin blind salamander as endangered in accordance with sections 3(6) 
and 4(a)(1) of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The Austin blind salamander proposed 
for listing in this rule is highly restricted in its range, and the 
threats occur throughout its entire range. Therefore, the threats to 
the survival of this species are not restricted to any particular 
significant portion of that range. Accordingly, our assessment and 
proposed determination applies to the species throughout its entire 
range.

Jollyville Plateau Salamander

    The primary threat to this species is habitat modification (Factor 
A) in the form of reduced flows and degradation of water quality of 
spring habitats as a result of human population growth and subsequent 
urbanization within the watersheds and recharge and contributing zones 
of the Edwards Aquifer. Substantial human population growth is ongoing 
within this species' range. The Texas State Data Center (2008, p. 1) 
has reported a population increase of 84 percent and 597 percent for 
Travis and Williamson Counties, Texas, respectively. This population 
growth is likely to result in considerable urbanization within the 
watersheds that contribute to spring flow and thereby influence water 
quality within the salamander's habitat. Urbanization leads to 
increases in water demand and reduced water quality from erosion, 
sedimentation, contaminants, and nutrient loads as well as decreases in 
aquatic invertebrates (the salamanders' prey base). Specifically, 
elevated PAH and conductivity levels as well as excessive sedimentation 
have been documented within Jollyville Plateau salamander habitat and 
have been associated with population declines observed during 
monitoring (COA 2001, pp. 101, 126; O'Donnell et al. 2006, pp. 37, 47). 
Poor water quality, particularly elevated nitrates, is also believed to 
be a cause of morphological deformities observed in individual 
Jollyville Plateau salamanders (O'Donnell et al. 2006, pp. 26, 37).
    We analyzed the impervious cover estimates of each watershed within 
the Jollyville Plateau salamander's range, along with the amount of 
land currently managed as open space that could possible contribute 
water quality benefits to the salamander's habitats. The watersheds 
within the Jollyville Plateau salamander's range have average 
impervious cover estimates that range from 5.72 percent to 34.32 
percent. Although the Balcones Canyonlands Preserve and other lands 
managed for open space within these watersheds likely provide some 
water quality benefits for this species, five out of the six watersheds 
that occur within its range have overall impervious cover estimates 
that can lead to sharp declines in water quality or cause permanent 
conditions of poor water quality (Schueler 1994, pp. 100-102). In 
consideration of this information and analysis, we believe the threat 
of habitat modification in the form of reduced water quality is ongoing 
and of high impact throughout the Jollyville Plateau salamander's 
range.
    Data indicate that water quality degradation in sites occupied by 
Jollyville Plateau salamanders continues to occur despite the existence 
of current regulatory mechanisms in place to protect water quality 
(Turner 2005a, pp. 8-17, O'Donnell et al. 2006, p. 29); therefore, 
these mechanisms are not adequate to protect this species and its 
habitat. Therefore, we consider the inadequacy of existing regulatory 
mechanisms (Factor D) to be an ongoing threat of high impact.
    The Edwards Aquifer is at risk from a variety of sources of 
pollutants (Ross 2011, p. 4), including hazardous materials that could 
be spilled or leaked, potentially resulting in the contamination of 
both surface and groundwater resources (Service 2005, pp. 1.6-14-1.6-
15). A catastrophic spill could occur if a truck transporting hazardous 
materials overturned and spilled its contents over the recharge zone of 
the aquifer. The transport of hazardous materials is common on many 
highways that serve as major transportation routes (Service 2005, p. 
1.6-13).
    A number of point-sources of pollutants exist within the Jollyville 
Plateau salamander's range, including leaking underground storage tanks 
and sewage spills from pipelines (COA 2001, pp. 16, 21, 74). A 
significant hazardous materials spill within a stream drainage for the 
Jollyville Plateau salamander could have the potential to threaten the 
long-term survival and sustainability of multiple populations. Because 
of these reasons, we believe the threat of habitat modification in the 
form of water quality degradation and contamination from hazardous 
materials spills to be an ongoing threat of low impact to this species.
    Construction activities resulting from urban development are a 
threat to both water quality and quantity because they can increase 
sedimentation and dewater springs by intercepting aquifer conduits. 
Increased sedimentation from construction activities has been linked to 
declines in Jollyville Plateau salamander counts at multiple sites 
(Turner 2003, p. 24; O'Donnell et al. 2006, p. 34). Given that 
construction-related sediment loading is likely to occur from ongoing 
urbanization within the Jollyville Plateau salamander's range, we 
believe the threat of habitat modification in the form of water quality 
degradation and water reduction caused by construction activities from 
urban development to be an ongoing threat of high impact to this 
species.
    Another potential threat to the Jollyville Plateau salamander and 
its habitat is low flow conditions in the aquifer and within this 
species' surface habitat due to urbanization and recent drought 
conditions. The City of Austin found a negative correlation between 
urbanization and spring flows at Jollyville Plateau salamander sites 
(Turner 2003, p. 11). Field studies have also shown that a number of 
springs that support Jollyville Plateau salamanders have already gone 
dry periodically, and that spring waters resurface following rain 
events (O'Donnell et al. 2006, pp. 46-47).
    Future climate change could also affect water quantity and spring 
flow for the Jollyville Plateau salamander. Climate change could 
compound the threat of decreased water quantity at salamander spring 
sites. The effects of climate change on aquifer-dependant species is 
difficult to assess; however, the Edwards Aquifer is predicted to 
experience additional stress from climate change that could lead to 
decreased recharge and low or ceased

[[Page 50799]]

spring flows given increasing pumping demands (Lo[aacute]iciga et al. 
2000, pp. 192-193). Therefore, we believe habitat modification in the 
form of water quantity reduction, whether reduced spring flows is 
caused by climate change or in combination with other stressors, to be 
an ongoing threat of unknown impact to this species.
    All four salamanders are sensitive to direct physical habitat 
modification, such as those resulting from human recreational 
activities, impoundments, feral hogs, and livestock. Destruction of 
Jollyville Plateau salamander habitat has been attributed to vandalism 
(COA 2001, p. 21), human recreational use (COA 2001, p. 21), 
impoundments (O'Donnell et al. 2008, p.1; Bendik 2011b, pers. comm.), 
and feral hog activity (O'Donnell et al. 2006, pp. 34, 46). Because 
there is ongoing physical habitat modification occurring to known 
Jollyville Plateau salamander sites, we consider this threat to be 
ongoing and of low impact to this species.
    Chytrid fungus has also been documented on the feet of Jollyville 
Plateau salamanders in the wild, but with no visible symptoms of the 
disease (O'Donnell et al. 2006, pp. 22-23). Furthermore, there are no 
data to indicate whether disease or predation of any of the salamander 
species proposed for listing is a significant threat facing these 
species. Predation and disease (Factor C) may be affecting the 
Jollyville Plateau salamander species, but there is not enough evidence 
to consider these factors threats. Neither factor is at a level that we 
consider to be threatening the continued existence of the Jollyville 
Plateau salamander now or in the foreseeable future.
    Other natural or manmade factors (Factor E) affecting the 
Jollyville Plateau salamander include UV-B radiation, small population 
sizes, stochastic events, and synergistic and additive interactions 
among stressors. Increased levels of UV-B radiation, due to the 
depletion of stratospheric ozone layers has been shown to cause 
significant mortality and deformities that affect reproduction in 
amphibian species (Blaustein et al. 1997, p. 13,735), although the 
effects of UV-B radiation on this species are unknown. Small population 
sizes may act synergistically with other traits of the species (such as 
its limited distribution) to increase its overall risk of extinction 
(Davies et al. 2004, p. 270). Stochastic events, such as severe weather 
or demographic changes to the population, are also heightened threats 
because of the species' restricted range and small population sizes 
(Melbourne and Hastings 2008, p. 100). We therefore consider this to be 
an ongoing threat of medium impact.
    The population status of Jollyville Plateau salamanders is unknown 
at most of their sites. However, observations of Jollyville Plateau 
salamanders at several long-term monitoring sites have been decreasing 
in correspondence with habitat degradation (O'Donnell et al. 2006, pp. 
4, 48). We expect the downward trend to continue into the future as 
human population growth and urbanization drive further declines in 
habitat quality and quantity.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' Due to its susceptibility to threats 
that are ongoing throughout its entire range, we determine that the 
Jollyville Plateau salamander is currently on the brink of extinction 
and therefore meets the definition of endangered. We find that the 
Jollyville Plateau salamander is presently in danger of extinction 
throughout its entire range based on the immediacy, severity, and scope 
of the threats described above. The Jollyville Plateau salamander 
species is proposed as endangered, rather than threatened, because the 
threats are occurring now or are imminent, and their potential impacts 
to the species would be catastrophic given the very limited range of 
the species, making the salamander at risk of extinction at the present 
time. Therefore, on the basis of the best available scientific and 
commercial information, we propose listing the Jollyville Plateau 
salamander as endangered in accordance with sections 3(6) and 4(a)(1) 
of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The Jollyville Plateau salamander 
proposed for listing in this rule is highly restricted in its range, 
and the threats occur throughout its entire range. Therefore, the 
threats to the survival of this species are not restricted to any 
particular significant portion of that range. Accordingly, our 
assessment and proposed determination applies to the species throughout 
its entire range.

Georgetown Salamander

    The primary threat to this species is habitat modification (Factor 
A) in the form of reduced flows and degradation of water quality of 
spring habitats as a result of urbanization within the watersheds and 
recharge and contributing zones of the Edwards Aquifer. Williamson 
County, Texas, is experiencing tremendous human population growth. An 
increase of 597 percent from 2000 to 2040 is currently projected (Texas 
State Data Center 2008, p.1). Along with human population growth, we 
expect more urbanization, which leads to increases in sedimentation, 
contaminants, and nutrient loads as well as decreases in aquatic 
invertebrates (the salamanders' prey base).
    We analyzed the impervious cover estimates of each watershed within 
the Georgetown salamander's range, along with the amount of land 
currently managed as open space that could possibly contribute water 
quality benefits to the salamander's habitat. The watersheds within the 
Georgetown salamander's range have average impervious cover estimates 
that range from 0.59 percent to 9.60 percent. Five out of the six 
watersheds within this species' range are well below impervious cover 
levels that can lead to declines in water quality.
    Although our analyses indicated relatively low levels of impervious 
cover throughout the watersheds within the Georgetown salamander's 
range, there are developed areas that could be affecting the water 
quality at sites known to be occupied by the Georgetown salamander. 
Moreover, existing regulations in Williamson County do not address many 
of the sources of groundwater pollution that are typically associated 
with urbanized areas; therefore, these regulations are not adequate to 
protect this species and its habitat. With only two large tracts (64 ac 
[25.9 ha] and 145 ac [58.7 ha]) protected as open space within the 
Georgetown salamander's range, it is unlikely the water quality for 
this species' habitat will be protected as development continues into 
the foreseeable future. In consideration of this information and 
analysis, we believe the threat of habitat modification in the form of 
reduced water quality is ongoing and of high impact throughout the 
Georgetown salamander's range.
    In regards to regulatory mechanisms to protect water quality, it is 
unlikely that water quality within the Georgetown salamander's habitat 
will be maintained or protected as urbanization occurs in these 
watersheds into the foreseeable future. Therefore, we consider the 
inadequacy of existing regulatory mechanisms (Factor D) to be an 
ongoing threat of high impact.
    The Edwards Aquifer is at risk from a variety of sources of 
pollutants (Ross

[[Page 50800]]

2011, p. 4), including hazardous materials that could be spilled or 
leaked, potentially resulting in the contamination of both surface and 
groundwater resources (Service 2005, pp. 1.6-14-1.6-15). A catastrophic 
spill could occur if a truck transporting hazardous materials 
overturned and spilled its contents over the recharge zone of the 
aquifer. Interstate Highway 35 crosses watersheds that contribute 
groundwater to spring sites known to be occupied by the Georgetown 
salamander.
    The Georgetown salamander is also at risk from several other point 
sources of pollutants, including wastewater pipelines, chlorinated 
drinking water lines, and septic systems. A significant hazardous 
materials spill within a stream drainage for the Georgetown salamander 
could have the potential to threaten the long-term survival and 
sustainability of multiple populations. For these reasons, we believe 
the threat of habitat modification in the form of water quality 
degradation and contamination from hazardous materials spills to be an 
ongoing threat of medium impact to this species.
    Construction activities resulting from urban development are a 
threat to both water quality and quantity because they can increase 
sedimentation and dewater springs by intercepting aquifer conduits. 
There are currently three active rock quarries located near Georgetown 
salamander sites within Williamson County, Texas, which may impact the 
species and its habitat, which could result in the destruction of 
spring sites, collapse of karst caverns, degradation of water quality, 
and reduction of water quantity (Ekmekci 1990, p. 4). Given that 
construction-related sediment loading is likely to occur within the 
rapidly developing range of the Georgetown salamander, we believe the 
threat of habitat modification in the form of water quality degradation 
and water reduction caused by construction activities from urban 
development to be an ongoing threat of medium impact to this species.
    Another potential threat to the Georgetown salamander and its 
habitat is low flow conditions in the aquifer and within this species' 
surface habitat due to urbanization and recent drought conditions. The 
San Gabriel Springs (Georgetown salamander habitat) are now only 
intermittently flowing in the summer due to pumping from nearby water 
wells (TPWD 2011a, p. 9). Salamanders have not been seen on the surface 
there since 1991 (Chippindale et al. 2000, p. 40; Pierce 2011b, pers. 
comm.). Although Eurycea salamanders may spend some time below the 
surface in underground aquatic habitat areas to adapt to periodic flow 
losses (O'Donnell et al. 2006, p. 47), drying spring habitats can 
result in stranding salamanders (TPWD 2011a, p. 5). Also, prey 
availability is likely low underground due to the lack of primary 
production (Hobbs and Culver 2009, p. 392).
    Future climate change could also affect water quantity and spring 
flow for the Georgetown salamander. Climate change could compound the 
threat of decreased water quantity at salamander spring sites. The 
effects of climate change on aquifer-dependant species is difficult to 
assess; however, the Edwards Aquifer is predicted to experience 
additional stress from climate change that could lead to decreased 
recharge and low or ceased spring flows given increasing pumping 
demands (Lo[aacute]iciga et al. 2000, pp. 192-193). In consideration of 
the information presented above, we believe habitat modification in the 
form of water quantity reduction to be an ongoing threat of high impact 
to this species.
    All four salamanders are sensitive to direct physical habitat 
modification, such as those resulting from human recreational 
activities, impoundments, feral hogs, and livestock. Destruction of 
Georgetown salamander habitat has been attributed to direct human 
modification (TPWD 2011a, p. 9), feral hog activity (O'Donnell et al. 
2006, pp. 34, 46; Booker 2011, p. 1), and livestock activity (White 
2011, SWCA, pers. comm.). Because there is ongoing physical habitat 
modification occurring to known Georgetown salamander sites within a 
restricted range, we consider this to be an ongoing threat of low 
impact for this species.
    Predation and disease (Factor C) may be affecting the Georgetown 
salamander, but there is not enough evidence to consider these factors 
threats . Neither factor is at a level that we consider to be 
threatening the continued existence of the Georgetown salamander 
species now or in the foreseeable future.
    Other natural or manmade factors (Factor E) potentially affecting 
the Georgetown salamander include UV-B radiation, small population 
sizes, stochastic events, and synergistic and additive interactions 
among stressors. Increased levels of UV-B radiation, due to the 
depletion of stratospheric ozone layers has been shown to cause 
significant mortality and deformities in amphibian species (Blaustein 
et al. 1997, p. 13,735), although the effects of UV-B radiation on this 
species are unknown. Small population sizes may act synergistically 
with other traits of the species (such as its limited distribution) to 
increase its overall risk of extinction (Davies et al. 2004, p. 270). 
Stochastic events, such as severe weather or demographic changes to the 
population, are also heightened threats because of its restricted range 
and small population sizes (Melbourne and Hastings 2008, p. 100). We 
therefore consider this to be an ongoing threat of medium impact.
    The population status of Georgetown salamanders is unknown at all 
but two of their sites. A lack of long-term data prevents us from 
drawing conclusions on how Georgetown salamander populations may be 
changing over time. However, similar to Austin blind and Jollyville 
plateau salamander populations, we expect Georgetown salamander 
populations to trend downwards in the future as human population growth 
and urbanization in the area drive declines in habitat quality and 
quantity.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' Due to its susceptibility to threats 
that are ongoing throughout its entire range, we determine that the 
Georgetown salamander is currently on the brink of extinction and 
therefore meets the definition of endangered. We find that the 
Georgetown salamander is presently in danger of extinction throughout 
its entire range based on the immediacy, severity, and scope of the 
threats described above. The Georgetown salamander species is proposed 
as endangered, rather than threatened, because the threats are 
occurring now or are imminent, and their potential impacts to the 
species would be catastrophic given the very limited range of the 
species, making the salamander at risk of extinction at the present 
time. Therefore, on the basis of the best available scientific and 
commercial information, we propose listing the Georgetown salamander as 
endangered in accordance with sections 3(6) and 4(a)(1) of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The Georgetown salamander proposed 
for listing in this rule is highly restricted in its range, and the 
threats occur throughout its entire range. Therefore, the threats to 
the survival of this species are not restricted to any particular 
significant portion of that range. Accordingly, our assessment and

[[Page 50801]]

proposed determination applies to the species throughout its entire 
range.

Salado Salamander

    The primary threat to this species is habitat modification (Factor 
A) in the form of reduced flows and degradation of water quality of 
spring habitats as a result of urbanization within the watersheds and 
recharge and contributing zones of the Edwards Aquifer. Urbanization 
leads to increases in sedimentation, contaminants, and nutrient loads 
as well as decreases in aquatic invertebrates (the Salado salamander's 
prey base).
    We analyzed the impervious cover estimates of each watershed within 
the Salado salamander's range along with the amount of land currently 
managed as open space that could possibly contribute water quality 
benefits to the salamander's habitat. The two watersheds within the 
Salado salamander's range have 0.31 percent and 0.91 percent impervious 
cover. Although four known Salado salamander sites are located on 
large, undeveloped ranches (8,126 ac [3,288 ha] and 827 ac [335 ha]), a 
significant portion of the recharge zone for the Northern Segment of 
the Edwards Aquifer that supplies water to this species' habitat 
extends to areas outside of these properties. We could not identify any 
large tracts managed specifically as open space within the Salado 
salamander's range. We also could not identify any agreements in place 
to preserve or manage any properties for the benefit of this species or 
its habitat. Furthermore, population projections from the Texas State 
Data Center (2009, p. 19) estimate that Bell County will increase in 
population from 237,974 in 2000, to 397,741 in 2040, a 67 percent 
increase over the 40-year period. In consideration of this information 
and analysis, we believe the threat of habitat modification in the form 
of water quality degradation is ongoing and of medium impact throughout 
the Salado salamander's range.
    In regards to adequate regulatory mechanisms to protect water 
quality, it is unlikely that water quality within the Salado 
salamander's habitat will be protected if development occurs in these 
watersheds into the foreseeable future. We therefore consider the 
inadequacy of existing regulatory mechanisms (Factor D) to be an 
ongoing threat of high impact.
    The Edwards Aquifer is at risk from a variety of sources of 
pollutants (Ross 2011, p. 4), including hazardous materials that could 
be spilled or leaked, potentially resulting in the contamination of 
both surface and groundwater resources (Service 2005, pp. 1.6-14-1.6-
15). A catastrophic spill could occur if a truck transporting hazardous 
materials overturned and spilled its contents over the recharge zone of 
the aquifer. Salado salamander sites located downstream of Interstate 
Highway 35 may be particularly vulnerable due to their proximity to 
this major transportation corridor. Should a hazardous materials spill 
occur at the Interstate Highway 35 bridge that crosses at Salado Creek, 
this species could be at risk from contaminants entering the water 
flowing into its surface habitat downstream.
    Several groundwater contamination incidents have occurred within 
Salado salamander habitat (Price et al. 1999, p. 10). Because these 
groundwater contamination events are already occurring and because the 
Salado salamander's range is restricted to only a few known spring 
sites, we consider the threat of hazardous materials spills to be 
ongoing and of high impact to this species.
    Construction activities resulting from urban development are a 
threat to both water quality and quantity because they can increase 
sedimentation and dewater springs by intercepting aquifer conduits. The 
Service is not aware of any specific, large-scale construction 
activities currently ongoing within the Salado salamander's range. 
However, because the human population is increasing rapidly in this 
area, urbanization and subsequent construction activities are likely to 
impact the few known Salado salamander populations within the 
foreseeable future. Thus, we believe construction activities are an 
ongoing threat of low impact to this species.
    Another potential threat to the Salado salamander and its habitat 
is low flow conditions in the aquifer and within this species' surface 
habitat due to urbanization and recent drought conditions. Robertson 
Springs (Salado salamander habitat) reportedly went temporarily dry in 
2009 (TPWD 2011a, p. 5). Although Eurycea salamanders may spend some 
time below the surface in underground aquatic habitat areas to adapt to 
periodic flow losses (O'Donnell et al. 2006, p. 47), drying spring 
habitats can result in stranding salamanders (TPWD 2011a, p. 5). Also, 
prey availability is likely low underground due to the lack of primary 
production (Hobbs and Culver 2009, p. 392).
    Future climate change could also affect water quantity and spring 
flow for the Salado salamander. Climate change could compound the 
threat of decreased water quantity at salamander spring sites. The 
effects of climate change on aquifer-dependant species is difficult to 
assess; however, the Edwards Aquifer is predicted to experience 
additional stress from climate change that could lead to decreased 
recharge and low or ceased spring flows given increasing pumping 
demands (Lo[aacute]iciga et al. 2000, pp. 192-193). In consideration of 
the information presented above, we believe that habitat modification 
in the form of water quantity reduction to be an ongoing threat of 
medium magnitude to this species.
    All four salamanders are sensitive to direct physical habitat 
modification, such as those resulting from human recreational 
activities, impoundments, feral hogs, and livestock. Destruction of 
Salado salamander habitat has been attributed to direct human 
modification (including heavy machinery use, outflow channel 
reconstruction, and substrate alteration at Big Boiling Springs) and 
feral hog activity (Service 2010b, p. 6; Gluesenkamp 2011a, b, pers. 
comm.). Because there is ongoing physical habitat modification 
occurring to known Salado salamander sites within a very restricted 
range, we consider this threat resulting from human recreational 
activities to be ongoing and of low impact to this species. 
Furthermore, we consider the threats of impoundments, feral hogs, and 
livestock to be ongoing, but of low impact.
    Predation and disease (Factor C) may be affecting the Salado 
salamander, but there is not enough evidence to consider these factors 
threats. Neither factor is at a level that we consider to be 
threatening the continued existence of the Salado salamander species 
now or in the foreseeable future.
    Other natural or manmade factors (Factor E) affecting the Salado 
salamander include UV-B radiation, small population sizes, stochastic 
events, and synergistic and additive interactions among stressors. 
Increased levels of UV-B radiation, due to the depletion of 
stratospheric ozone layers has been shown to cause significant 
mortality and deformities in amphibian species (Blaustein et al. 1997, 
p. 13,735), although the effects of UV-B radiation on this species are 
unknown. Small population sizes may act synergistically with other 
traits of the species (such as its limited distribution) to increase 
its overall risk of extinction (Davies et al. 2004, p. 270). Stochastic 
events, such as severe weather or demographic changes to the 
population, are also heightened threats because of its restricted range 
and small population sizes (Melbourne and Hastings 2008, p. 100). We 
therefore consider this to be an ongoing threat of high impact.

[[Page 50802]]

    The population status of Salado salamanders is unknown. A lack of 
long-term data prevents us from drawing conclusions on how Salado 
salamander populations may be changing over time. However, similar to 
Austin blind and Jollyville plateau salamander populations, we expect 
Salado salamander populations to trend downwards in the future as human 
population growth and urbanization in the area drive declines in 
habitat quality and quantity. Due to its relatively small range and 
small number of populations, we believe the species' resiliency to the 
threats outlined above is low.
    The Act defines an endangered species as any species that is ``in 
danger of extinction throughout all or a significant portion of its 
range'' and a threatened species as any species ``that is likely to 
become endangered throughout all or a significant portion of its range 
within the foreseeable future.'' Due to its susceptibility to threats 
that are ongoing throughout its entire range, we determine that the 
Salado salamander is currently on the brink of extinction and therefore 
meets the definition of endangered. We find that the Salado salamander 
is presently in danger of extinction throughout its entire range, based 
on the immediacy, severity, and scope of the threats described above. 
This salamander species is proposed as endangered, rather than 
threatened, because the threats are occurring now or are imminent, and 
their potential impacts to the species would be catastrophic given the 
very limited range of the species, making the salamander at risk of 
extinction at the present time. Therefore, on the basis of the best 
available scientific and commercial information, we propose listing the 
Salado salamander as endangered in accordance with sections 3(6) and 
4(a)(1) of the Act.
    Under the Act and our implementing regulations, a species may 
warrant listing if it is endangered or threatened throughout all or a 
significant portion of its range. The Salado salamander proposed for 
listing in this rule is highly restricted in its range, and the threats 
occur throughout its entire range. Therefore, the threats to the 
survival of this species are not restricted to any particular 
significant portion of that range. Accordingly, our assessment and 
proposed determination applies to the species throughout its entire 
range.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing can result in public awareness 
and conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and requires that recovery actions be carried out for all listed 
species. The protection required by Federal agencies and the 
prohibitions against certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed, preparation of a draft and final 
recovery plan, and revisions to the plan as significant new information 
becomes available. The recovery outline guides the immediate 
implementation of urgent recovery actions and describes the process to 
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species, 
measurable criteria that determine when a species may be downlisted or 
delisted, and methods for monitoring recovery progress. Recovery plans 
also establish a framework for agencies to coordinate their recovery 
efforts and provide estimates of the cost of implementing recovery 
tasks. Recovery teams (comprised of species experts, Federal and State 
agencies, non-government organizations, and stakeholders) are often 
established to develop recovery plans. If we list these four central 
Texas salamanders, when completed, the recovery outline, draft recovery 
plan, and the final recovery plan will be available on our Web site 
(http://www.fws.gov/endangered), or from our Austin Ecological Services 
Field Office (see FOR FURTHER INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a broad range of partners, including other Federal 
agencies, States, Tribal, non-governmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (for example, restoration of native vegetation), research, 
captive propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. To achieve recovery of these four species requires 
cooperative conservation efforts on private, local government, and 
other lands.
    If these species are listed, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost share grants for non-Federal landowners, the 
academic community, and non-governmental organizations. In addition, 
pursuant to section 6 of the Act, the State of Texas would be eligible 
for Federal funds to implement management actions that promote the 
protection and recovery of the Austin blind, Jollyville Plateau, 
Georgetown, and Salado salamanders. Information on our grant programs 
that are available to aid species recovery can be found at: http://www.fws.gov/grants.
    Although the Austin blind, Jollyville Plateau, Georgetown, and 
Salado salamanders are only proposed for listing under the Act at this 
time, please let us know if you are interested in participating in 
recovery efforts for this species. Additionally, we invite you to 
submit any new information on this species whenever it becomes 
available and any information you may have for recovery planning 
purposes (see FOR FURTHER INFORMATION CONTACT).
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as 
endangered or threatened and with respect to its critical habitat, if 
any is designated. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR part 402. 
Section 7(a)(4) of the Act requires Federal agencies to confer with the 
Service on any action that is likely to jeopardize the continued 
existence of a species proposed for listing or result in destruction or 
adverse modification of proposed critical habitat. If a species is 
listed subsequently, section 7(a)(2) of the Act requires Federal 
agencies to ensure that activities they authorize, fund, or carry out 
are not likely to jeopardize the continued existence of the species or 
destroy or adversely modify its critical habitat. If a Federal

[[Page 50803]]

action may affect a listed species or its critical habitat, the 
responsible Federal agency must enter into consultation with the 
Service.
    Federal agency actions within the species habitat that may require 
conference or consultation or both as described in the preceding 
paragraph include, but are not limited to, issuance of section 404 
Clean Water Act permits by the U.S. Army Corps of Engineers; 
construction and management of gas pipeline and power line rights-of-
way by the Federal Energy Regulatory Commission; Federal Emergency 
Management Agency for floodplain map revisions; U.S. Department of 
Agriculture Rural Development grants; Housing and Urban Development 
grants; Service for Partners projects; Service issuance of section 10 
permits under the Act; construction and maintenance of roads or 
highways by the Federal Highway Administration; Natural Resources 
Conservation Service funded projects; and Environmental Protection 
Agency pesticide registration.
    The Act and its implementing regulations set forth a series of 
general prohibitions and exceptions that apply to all endangered 
wildlife. The prohibitions of section 9(a)(2) of the Act, codified at 
50 CFR 17.21 for endangered wildlife, in part, make it illegal for any 
person subject to the jurisdiction of the United States to take 
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect; or to attempt any of these), import, export, ship 
in interstate commerce in the course of commercial activity, or sell or 
offer for sale in interstate or foreign commerce any listed species. 
Under the Lacey Act (18 U.S.C. 42-43; 16 U.S.C. 3371-3378), it is also 
illegal to possess, sell, deliver, carry, transport, or ship any such 
wildlife that has been taken illegally. Certain exceptions apply to 
agents of the Service and State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered and threatened wildlife species under certain 
circumstances. Regulations governing permits are codified at 50 CFR 
17.22 for endangered species, and at 17.32 for threatened species. With 
regard to endangered wildlife, a permit must be issued for the 
following purposes: For scientific purposes, to enhance the propagation 
or survival of the species, and for incidental take in connection with 
otherwise lawful activities.
    It is our policy, as published in the Federal Register on July 1, 
1994 (59 FR 34272), to identify to the maximum extent practicable at 
the time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act. The intent of this 
policy is to increase public awareness of the effect of a proposed 
listing on proposed and ongoing activities within the range of the 
species proposed for listing. The following activities could 
potentially result in a violation of section 9 of the Act; this list is 
not comprehensive:
    (1) Unauthorized collecting, handling, possessing, selling, 
delivering, carrying, or transporting of the species, including import 
or export across State lines and international boundaries, except for 
properly documented antique specimens of these taxa at least 100 years 
old, as defined by section 10(h)(1) of the Act.
    (2) Introduction of nonnative species that compete with or prey 
upon any of the four salamanders, such as the introduction of 
competing, nonnative aquatic animals to the State of Texas.
    (3) The unauthorized release of biological control agents that 
attack any life stage of these four species.
    (4) Unauthorized modification of the spring opening, stream 
channel, or water flow of any spring or stream or removal or 
destruction of substrate in any body of water in which any of the four 
salamanders are known to occur.
    (5) The interception of groundwater such that it reduces water flow 
into any waters where any of the four salamanders are known to occur.
    (6) Unauthorized discharge of chemicals or fill material into any 
waters in which any of the four salamanders are known to occur.
    If the four central Texas salamanders are listed under the Act, the 
State of Texas' endangered species law is automatically invoked, which 
would also prohibit take of these species and encourage conservation by 
State government agencies. Chapter 68, section 68.002 of the TPWD's 
Code defines State-level endangered species as those species of fish or 
wildlife indigenous to Texas that are listed on: (1) The United States 
List of Endangered and Threatened Wildlife; or (2) the list of fish or 
wildlife threatened with Statewide extinction as filed by the director 
of the department. Further, the State of Texas may enter into 
agreements with Federal agencies to administer and manage any area 
required for the conservation, management, enhancement, or protection 
of endangered species. Funds for these activities could be made 
available under section 6 of the Act (Cooperation with the States). 
Thus, the Federal protection afforded to these species by listing them 
as endangered species will be reinforced and supplemented by protection 
under State law.
    Questions regarding whether specific activities would constitute a 
violation of section 9 of the Act should be directed to the Austin 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT). 
Requests for copies of the regulations concerning listed animals and 
general inquiries regarding prohibitions and permits may be addressed 
to the U.S. Fish and Wildlife Service, Endangered Species Permits, 
10711 Burnet Road, Suite 200, Austin, TX 78758; telephone 512-490-0057; 
facsimile 512-490-0974.

Prudency Determination

    Section 4 of the Act, as amended, and implementing regulations (50 
CFR 424.12), require that, to the maximum extent prudent and 
determinable, the Secretary designate critical habitat at the time the 
species is determined to be endangered or threatened. Our regulations 
at 50 CFR 424.12(a)(1) state that the designation of critical habitat 
is not prudent when one or both of the following situations exist: (1) 
The species is threatened by taking or other activity and the 
identification of critical habitat can be expected to increase the 
degree of threat to the species; or (2) the designation of critical 
habitat would not be beneficial to the species.
    There is no documentation that the four Texas salamanders are 
significantly threatened by collection. Although human visitation to 
four Texas salamanders' habitat carries with it the possibility of 
introducing infectious disease and potentially increasing other threats 
where the salamanders occur, the locations of important recovery areas 
are already accessible to the public through Web sites, reports, online 
databases, and other easily accessible venues. Therefore, identifying 
and mapping critical habitat is unlikely to increase threats to the 
four Texas salamander species or their habitats. In the absence of 
finding that the designation of critical habitat would increase threats 
to a species, if there are any benefits to a critical habitat 
designation, then a prudent finding is warranted. The potential 
benefits of critical habitat to the four Texas salamanders include: (1) 
Triggering consultation under section 7 of the Act where a Federal 
nexus may not otherwise occur (for example, a critical habitat unit may 
become unoccupied, and without critical habitat designation, a 
consultation would not occur on a project that may affect an unoccupied 
area); (2) focusing conservation activities on the most essential 
features and areas; (3) providing educational

[[Page 50804]]

benefits to State or county governments, or private entities; and (4) 
preventing people from causing inadvertent harm to the species. 
Therefore, because we have determined that the designation of critical 
habitat will not likely increase the degree of threat to any of the 
four salamander species and may provide some measure of benefit, we 
find that designation of critical habitat is prudent for the Austin 
blind, Jollyville Plateau, Georgetown, and Salado salamanders.

Proposed Critical Habitat Designation for the Four Central Texas 
Salamanders

Background

    It is our intent to discuss below only those topics directly 
relevant to the designation of critical habitat for the Austin blind, 
Jollyville Plateau, Georgetown, and Salado salamanders in this section 
of the proposed rule.
    Critical habitat is defined in section 3 of the Act as:
    (1) The specific areas within the geographical area occupied by the 
species, at the time it is listed in accordance with the Act, on which 
are found those physical or biological features
    (a) Essential to the conservation of the species and
    (b) Which may require special management considerations or 
protection; and
    (2) Specific areas outside the geographical area occupied by the 
species at the time it is listed, upon a determination that such areas 
are essential for the conservation of the species.
    Conservation, as defined under section 3 of the Act, means to use 
and the use of all methods and procedures that are necessary to bring 
an endangered or threatened species to the point at which the measures 
provided pursuant to the Act are no longer necessary. Such methods and 
procedures include, but are not limited to, all activities associated 
with scientific resources management such as research, census, law 
enforcement, habitat acquisition and maintenance, propagation, live 
trapping, and transplantation, and, in the extraordinary case where 
population pressures within a given ecosystem cannot be otherwise 
relieved, may include regulated taking.
    Critical habitat receives protection under section 7 of the Act 
through the requirement that Federal agencies ensure, in consultation 
with the Service, that any action they authorize, fund, or carry out is 
not likely to result in the destruction or adverse modification of 
critical habitat. The designation of critical habitat does not affect 
land ownership or establish a refuge, wilderness, reserve, preserve, or 
other conservation area. Such designation does not allow the government 
or public to access private lands. Such designation does not require 
implementation of restoration, recovery, or enhancement measures by 
non-Federal landowners. Where a landowner requests Federal agency 
funding or authorization for an action that may affect a listed species 
or critical habitat, the consultation requirements of section 7(a)(2) 
of the Act would apply, but even in the event of a destruction or 
adverse modification finding, the obligation of the Federal action 
agency and the landowner is not to restore or recover the species, but 
to implement reasonable and prudent alternatives to avoid destruction 
or adverse modification of critical habitat.
    Under the first prong of the Act's definition of critical habitat, 
areas within the geographical area occupied by the species at the time 
it was listed are included in a critical habitat designation if they 
contain physical or biological features (1) which are essential to the 
conservation of the species and (2) which may require special 
management considerations or protection. For these areas, critical 
habitat designations identify, to the extent known using the best 
scientific data available, those physical or biological features that 
are essential to the conservation of the species (such as space, food, 
cover, and protected habitat). In identifying those physical or 
biological features within an area, we focus on the principal 
constituent elements (primary constituent elements such as roost sites, 
nesting grounds, seasonal wetlands, water quality, tide, soil type) 
that are essential to the conservation of the species. Primary 
constituent elements are the elements or components of physical or 
biological features that are essential to the conservation of the 
species.
    Under the second prong of the Act's definition of critical habitat, 
we can designate critical habitat in areas outside the geographical 
area occupied by the species at the time it is listed, upon a 
determination that such areas are essential for the conservation of the 
species. For example, an area currently occupied by the species but 
that was not occupied at the time of listing may be essential to the 
conservation of the species and may be included in the critical habitat 
designation. We designate critical habitat in areas outside the 
geographical area occupied by a species only when a designation limited 
to its range would be inadequate to ensure the conservation of the 
species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific data available. Further, our Policy on 
Information Standards Under the Endangered Species Act (published in 
the Federal Register on July 1, 1994 (59 FR 34271)), the Information 
Quality Act (section 515 of the Treasury and General Government 
Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554; H.R. 5658)), 
and our associated Information Quality Guidelines, provide criteria, 
establish procedures, and provide guidance to ensure that our decisions 
are based on the best scientific data available. They require our 
biologists, to the extent consistent with the Act and with the use of 
the best scientific data available, to use primary and original sources 
of information as the basis for recommendations to designate critical 
habitat.
    When we are determining which areas should be designated as 
critical habitat, our primary source of information is generally the 
information developed during the listing process for the species. 
Additional information sources may include the recovery plan for the 
species, articles in peer-reviewed journals, conservation plans 
developed by States and counties, scientific status surveys and 
studies, biological assessments, other unpublished materials, or 
experts' opinions or personal knowledge.
    Habitat is dynamic, and species may move from one area to another 
over time. We recognize that critical habitat designated at a 
particular point in time may not include all of the habitat areas that 
we may later determine are necessary for the recovery of the species. 
For these reasons, a critical habitat designation does not signal that 
habitat outside the designated area is unimportant or may not be needed 
for recovery of the species. Areas that are important to the 
conservation of the species, both inside and outside the critical 
habitat designation, will continue to be subject to: (1) Conservation 
actions implemented under section 7(a)(1) of the Act, (2) regulatory 
protections afforded by the requirement in section 7(a)(2) of the Act 
for Federal agencies to ensure their actions are not likely to 
jeopardize the continued existence of any endangered or threatened 
species, and (3) the prohibitions of section 9 of the Act if actions 
occurring in these areas may affect the species. Federally funded or 
permitted projects affecting listed species outside their designated 
critical habitat areas may still result in jeopardy

[[Page 50805]]

findings in some cases. These protections and conservation tools will 
continue to contribute to recovery of this species. Similarly, critical 
habitat designations made on the basis of the best available 
information at the time of designation will not control the direction 
and substance of future recovery plans, habitat conservation plans 
(HCPs), or other species conservation planning efforts if new 
information available at the time of these planning efforts calls for a 
different outcome.

Physical or Biological Features

    In accordance with section 3(5)(A)(i) and 4(b)(1)(A) of the Act and 
regulations at 50 CFR 424.12, in determining which areas within the 
geographic area occupied by the species at the time of listing to 
designate as critical habitat, we consider the physical or biological 
features that are essential to the conservation of the species and 
which may require special management considerations or protection. 
These include, but are not limited to:
    (1) Space for individual and population growth and for normal 
behavior;
    (2) Food, water, air, light, minerals, or other nutritional or 
physiological requirements;
    (3) Cover or shelter;
    (4) Sites for breeding, reproduction, or rearing (or development) 
of offspring; and
    (5) Habitats that are protected from disturbance or are 
representative of the historical, geographic, and ecological 
distributions of a species.
    We derive the specific physical or biological features required for 
the four central Texas salamander species from studies of these 
species' habitat, ecology, and life history as described below. 
Additional information can be found in the listing portion of this 
proposed rule. We have determined that the aquatic ecosystem of the 
Barton Springs Segment of the Edwards Aquifer is the physical or 
biological feature essential for the Austin blind salamander. We have 
determined that the aquatic ecosystem of the Northern Segment of the 
Edwards Aquifer is the physical or biological feature essential for the 
Jollyville Plateau salamander, the Georgetown salamander, and the 
Salado salamander.
Space for Individual and Population Growth and for Normal Behavior
Austin Blind Salamander
    The Austin blind salamander has been found where water emerges from 
the ground as a free-flowing spring. However, this species is rarely 
seen at the surface of the spring, so it is assumed that it is 
subterranean for most of its life (Hillis et al. 2001, p. 267). 
Supporting this assumption is the fact that the species' physiology is 
cave-adapted, with reduced eyes and pale coloration (Hillis et al. 
2001, p. 267). Most individuals found on the surface near spring 
openings are juveniles (Hillis et al. 2001, p. 273). Austin blind 
salamanders have been found in the streambed a short distance (about 33 
ft (10 m)) downstream of Sunken Gardens Spring (Dries, 2011, pers. 
comm.). Therefore, based on the information above, we identify springs, 
associated streams, and underground spaces within the aquifer to be the 
primary components of the physical or biological features essential to 
the conservation of this species.
Jollyville Plateau Salamander
    The Jollyville Plateau salamander occurs where water emerges from 
the ground as a free-flowing spring and stream. Within the spring 
ecosystem, proximity to the springhead is important because of the 
appropriate stable water chemistry and temperature, substrate, and flow 
regime. Jollyville Plateau salamanders are known to use the underground 
aquifer for habitat when surface habitats go dry (Bendik 2011a, p. 31). 
Georgetown salamanders, a closely related species, are found up to 164 
ft (50 m) from a spring opening (Pierce et al. 2011a, p. 4), but they 
are most abundant within the first 16 ft (5 m) (Pierce et al. 2010, p. 
294). Forms of Jollyville Plateau salamander with cave morphology have 
been found in several underground streams (Chippindale et al. 2000, pp. 
36-37; TPWD 2011a, pp. 9-10). Therefore, based on the information 
above, we identify springs, associated streams, and underground spaces 
within the aquifer to be the primary components of the physical or 
biological features essential to the conservation of this species.
Georgetown Salamander
    The Georgetown salamander occurs where water emerges from the 
ground as a free-flowing spring and stream. Within the spring 
ecosystem, proximity to the springhead is important because of the 
appropriate stable water chemistry and temperature, substrate, and flow 
regime. Georgetown salamanders are found within 164 ft (50 m) of a 
spring opening (Pierce et al. 2011a, p. 4), but they are most abundant 
within the first 16 ft (5 m) (Pierce et al. 2010, p. 294). Georgetown 
salamanders are also thought to use the underground aquifer for 
habitat, similar to other closely related Eurycea species. Forms of 
Georgetown salamander with cave morphology have been found at two 
locations (TPWD 2011a, p. 8), indicating that they spend most of their 
lives underground at these locations. Therefore, based on the 
information above, we identify springs, associated streams, and 
underground spaces within the aquifer to be the primary components of 
the physical or biological features essential to the conservation of 
this species.
Salado Salamander
    The Salado salamander occurs where water emerges from the ground as 
a free-flowing spring and stream. Within the spring ecosystem, 
proximity to the springhead is important because of the appropriate 
stable water chemistry and temperature, substrate, and flow regime. 
Eurycea salamanders are rarely found more than 66 ft (20 m) from a 
spring source (TPWD 2011, p. 3). However, Georgetown salamanders, a 
similar species, are found up to 164 ft (50 m) downstream of a spring 
opening. Salado salamanders are also thought to use the underground 
aquifer for habitat in times of drought when surface habitat is no 
longer available or suitable (TPWD 2011, p. 3), similar to other 
closely related Eurycea species (Bendik 2011a, p. 31). Therefore, based 
on the information above, we identify springs, associated streams, and 
underground spaces within the aquifer to be the primary components of 
the physical or biological features essential to the conservation of 
this species.
Food, Water, Air, Light, Minerals, or Other Nutritional or 
Physiological Requirements
Austin Blind Salamander
    No species-specific dietary study has been completed, but the diet 
of the Austin blind salamander is presumed to be similar to other 
Eurycea species, consisting of small aquatic invertebrates such as 
amphipods, copepods, isopods, and insect larvae (reviewed in COA 2001, 
pp. 5-6). The feces of one wild-caught Austin blind salamander 
contained amphipods, ostracods, copepods, and plant material (Hillis et 
al. 2001, p. 273).
    Austin blind salamanders are strictly aquatic and spend their 
entire lives submersed in water from the Barton Springs Segment of the 
Edwards Aquifer (Hillis et al. 2001, p. 273). These salamanders, and 
the prey that they feed on, require water sourced from the Edwards 
Aquifer at sufficient flows (quantity) to meet all of their 
physiological requirements. This water

[[Page 50806]]

should be flowing and unchanged in chemistry, temperature, and volume 
from natural conditions. The average water temperature at Austin blind 
salamander sites in Barton Springs is between 67.8 and 72.3 [deg]F 
(19.9 and 22.4 [deg]C) (COA 2011b, unpublished data).
    Edwards Aquifer Eurycea are adapted to a lower ideal range of 
oxygen saturations compared to other salamanders (Turner 2009, p. 11). 
However, Eurycea salamanders need dissolved oxygen concentrations to be 
above a certain concentration, as the co-occurring Barton Springs 
salamander demonstrates declining abundance with declining dissolved 
oxygen levels (Turner 2009, p. 14). Woods et al. (2010, p. 544) 
observed a number of physiological effects to low dissolved oxygen 
concentrations (below 4.5 milligrams of oxygen per liter (mg 
L-1)) in the related San Marcos salamander, including 
decreased metabolic rates and decreased juvenile growth rates. Barton 
Springs salamander abundance is highest when dissolved oxygen is 
between 5 to 7 mg L-1 (Turner 2009, p. 12). Therefore, we 
assume that the dissolved oxygen level of water is important to the 
Austin blind salamander as well. The mean annual dissolved oxygen (from 
2003 through 2011) at Main Spring, Eliza Spring, and Sunken Garden 
Spring is 6.36, 5.89, and 5.95 mg L-1, respectively (COA 
2011b, unpublished data).
    The conductivity of water is also important to salamander 
physiology because it is related to the concentration of ions in the 
water. Increased conductivity is associated with increased water 
contamination and decreased Eurycea abundance (Willson and Dorcas 2003, 
pp. 766-768; Bowles et al. 2006, pp. 117-118). The lower limit of 
observed conductivity in developed Jollyville Plateau salamander sites 
where salamander densities were lower was 800 microsiemens per 
centimeter ([mu]S cm-\1\) (Bowles et al. 2006, p. 117). 
Salamanders were significantly more abundant at undeveloped sites where 
water conductivity averaged 600 [mu]S cm-\1\ (Bowles et al. 
2006, p. 117). Because of its similar physiology to the Jollyville 
Plateau salamander, we assume that the Austin blind salamander will 
have a similar response to elevated water conductance. Although one 
laboratory study on the related San Marcos salamander demonstrated that 
conductivities up to 2738 [mu]S cm-1 had no measurable 
effect on adult activity (Woods and Poteet 2006, p. 5), it remains 
unclear how elevated water conductance might affect juveniles or the 
long-term health of salamanders in the wild. In the absence of better 
information on the sensitivity of salamanders to changes in 
conductivity (or other contaminants), it is reasonable to assume that 
salamander survival, growth, and reproduction will be most successful 
when water quality is unaltered from natural aquifer conditions. The 
average water conductance at Main Spring, Eliza Spring, and Sunken 
Garden Spring is between 605 and 740 [mu]S cm-\1\, 
respectively (COA 2011b, unpublished data).
    Therefore, based on the information above, we identify aquatic 
invertebrates and water from the Barton Springs Segment of the Edwards 
Aquifer with adequate dissolved oxygen concentration, water 
conductance, and water temperature to be the essential components of 
the physical or biological features essential to the conservation of 
this species.
Jollyville Plateau Salamander
    As in other Eurycea species, the Jollyville Plateau salamander 
feeds on aquatic invertebrates that commonly occur in spring 
environments (reviewed in COA 2001, pp. 5-6). A gut content analysis by 
the City of Austin demonstrated that this salamander preys on varying 
proportions of ostracods, copepods, mayfly larvae, fly larvae, snails, 
water mites, aquatic beetles, and stone fly larvae depending on the 
location of the site (Bendik 2011b, p. 55).
    Jollyville Plateau salamanders are strictly aquatic and spend their 
entire lives submersed in water from the Northern Segment of the 
Edwards Aquifer (COA 2001, pp. 3-4; Bowles et al. 2006, p. 112). These 
salamanders, and the prey that they feed on, require water sourced from 
the Edwards Aquifer at sufficient flows (quantity) to meet all of their 
physiological requirements. This water should be flowing and unchanged 
in chemistry, temperature, and volume from natural conditions. The 
average water temperature at Jollyville Plateau salamander sites with 
undeveloped watersheds ranges from 65.3 to 67.3 [deg]F (18.5 to 19.6 
[deg]C) (Bowles et al. 2006, p. 115).
    Edwards Aquifer Eurycea are adapted to a lower ideal range of 
oxygen saturations compared to other salamanders (Turner 2009, p. 11). 
However, Eurycea salamanders need dissolved oxygen concentrations to be 
above a certain concentration, as the related Barton Springs salamander 
demonstrates declining abundance with declining dissolved oxygen levels 
(Turner 2009, p. 14). In addition, Woods et al. (2010, p. 544) observed 
a number of physiological effects to low dissolved oxygen 
concentrations (below 4.5 mg L-\1\) in the related San 
Marcos salamander, including decreased metabolic rates and decreased 
juvenile growth rates. The average dissolved oxygen level of Jollyville 
Plateau salamander sites with little or no development in the watershed 
ranges from 5.6 to 7.1 mg L-\1\ (Bendik 2011a, p. 10). Based 
on this information, we conclude that the dissolved oxygen level of 
water is important to the Jollyville Plateau salamander for respiratory 
function.
    The conductivity of water is also important to salamander 
physiology because it is related to the concentration of ions in the 
water. Increased conductivity is associated with increased water 
contamination and decreased Eurycea abundance (Willson and Dorcas 2003, 
pp. 766-768; Bowles et al. 2006, pp. 117-118). The lower limit of 
conductivity in developed Jollyville Plateau salamander sites where 
salamander densities were lower was 800 [mu]S cm-\1\ (Bowles 
et al. 2006, p. 117). Salamanders were significantly more abundant at 
undeveloped sites where water conductivity averaged 600 [mu]S 
cm-\1\ (Bowles et al. 2006, p. 117). The average water 
conductance of Jollyville Plateau salamander sites with little or no 
development in the watershed ranges from 550 to 625 [mu]S 
cm-\1\ (Bendik 2011a, p. 10, Bowles et al. 2006, p.115). 
Although one laboratory study on the related San Marcos salamander 
demonstrated that conductivities up to 2738 [mu]S cm-\1\ had 
no measurable effect on adult activity (Woods and Poteet 2006, p. 5), 
it remains unclear how elevated water conductance might affect 
juveniles or the long-term health of salamanders in the wild. In the 
absence of better information on the sensitivity of salamanders to 
changes in conductivity (or other contaminants), it is reasonable to 
assume that salamander survival, growth, and reproduction will be most 
successful when water quality is unaltered from natural aquifer 
conditions.
    Therefore, based on the information above, we identify aquatic 
invertebrates and water from the Northern Segment of the Edwards 
Aquifer, including adequate dissolved oxygen concentration, water 
conductance, and water temperature, to be the essential components of 
the physical or biological features essential for the conservation of 
this species.

[[Page 50807]]

Georgetown Salamander
    No species-specific dietary study has been completed, but the diet 
of the Georgetown salamander is presumed to be similar to other Eurycea 
species, consisting of small aquatic invertebrates such as amphipods, 
copepods, isopods, and insect larvae (reviewed in COA 2001, pp. 5-6).
    Georgetown salamanders are strictly aquatic and spend their entire 
lives submersed in water from the Northern Segment of the Edwards 
Aquifer (Pierce et al. 2010, p. 296). These salamanders, and the prey 
that they feed on, require water sourced from the Edwards Aquifer at 
sufficient flows (quantity) to meet all of their physiological 
requirements (TPWD 2011a, p. 8). This water should be flowing and 
unchanged in chemistry, temperature, and volume from natural 
conditions. Normal water temperature at a relatively undisturbed 
Georgetown salamander site ranges from 68.4 to 69.8 [deg]F (20.2 to 
21.0 [deg]C) throughout the year (Pierce et al. 2010, p. 294).
    Edwards Aquifer Eurycea are adapted to a lower ideal range of 
oxygen saturations compared to other salamanders (Turner 2009, p. 11). 
However, Eurycea salamanders need dissolved oxygen concentrations to be 
above a certain threshold, as the related Barton Springs salamander 
demonstrates declining abundance with declining dissolved oxygen levels 
(Turner 2009, p. 14). In addition, Woods et al. (2010, p. 544) observed 
a number of physiological effects to low dissolved oxygen 
concentrations (below 4.5 mg L-1) in the related San Marcos 
salamander, including decreased metabolic rates and decreased juvenile 
growth rates. Georgetown salamander sites are characterized by high 
levels of dissolved oxygen, typically 6 to 8 mg L-1 (Pierce 
and Wall 2011, p. 33). Therefore, we assume that the dissolved oxygen 
level of water is important to the Georgetown salamander for 
respiratory function.
    The conductivity of water is also important to salamander 
physiology because it is related to the concentration of ions in the 
water. Increased conductivity is associated with increased water 
contamination and decreased Eurycea abundance (Willson and Dorcas 2003, 
pp. 766-768; Bowles et al. 2006, pp. 117-118). The lower limit of 
observed conductivity in developed Jollyville Plateau salamander sites 
where salamander densities were lower was 800 [micro]S cm-1 
(Bowles et al. 2006, p. 117). Salamanders were significantly more 
abundant at undeveloped sites where water conductivity averaged 600 
[micro]S cm-1 (Bowles et al. 2006, p. 117). Because of its 
similar physiology to the Jollyville Plateau salamander, we assume that 
the Georgetown salamander will have a similar response to elevated 
water conductance. Normal water conductance at a relatively undisturbed 
Georgetown salamander site ranges from 604 to 721 [micro]S 
cm-1 throughout the year (Pierce et al. 2010, p. 294). 
Although one laboratory study on the related San Marcos salamander 
demonstrated that conductivities up to 2738 [micro]S cm-1 
had no measurable effect on adult activity (Woods and Poteet 2006, p. 
5), it remains unclear how elevated water conductance might affect 
juveniles or the long-term health of salamanders in the wild. In the 
absence of better information on the sensitivity of salamanders to 
changes in conductivity (or other contaminants), it is reasonable to 
assume that salamander survival, growth, and reproduction will be most 
successful when water quality is unaltered from natural aquifer 
conditions.
    Therefore, based on the information above, we identify aquatic 
invertebrates and water from the Northern Segment of the Edwards 
Aquifer, including adequate dissolved oxygen concentration, water 
conductance, and water temperature, to be essential components of the 
physical or biological features essential for the conservation of this 
species.
Salado Salamander
    No species-specific dietary study has been completed, but the diet 
of the Salado salamander is presumed to be similar to other Eurycea 
species, consisting of small aquatic invertebrates such as amphipods, 
copepods, isopods, and insect larvae (reviewed in COA 2001, pp. 5-6).
    As with other central Texas Eurycea species, Salado salamanders are 
strictly aquatic. Individuals spend their entire lives submersed in 
water from the Northern Segment of the Edwards Aquifer (TPWD 2011a, p. 
3). These salamanders, and the prey that they feed on, require water 
sourced from the Edwards Aquifer at sufficient flows (quantity) to meet 
all of their physiological requirements. This water should be flowing 
and unchanged in chemistry, temperature, and volume from natural 
conditions.
    Edwards Aquifer Eurycea are adapted to a lower ideal range of 
oxygen saturations compared to other salamanders (Turner 2009, p. 11). 
However, Eurycea salamanders need dissolved oxygen concentrations to be 
above a certain threshold, as the related Barton Springs salamander 
demonstrates declining abundance with declining dissolved oxygen levels 
(Turner 2009, p. 14). In addition, Woods et al. (2010, p. 544) observed 
a number of physiological effects to low dissolved oxygen 
concentrations (below 4.5 mg L-1) in the related San Marcos 
salamander, including decreased metabolic rates and decreased juvenile 
growth rates. Therefore, we assume that the dissolved oxygen level of 
water is important to the Salado salamander for respiratory function.
    We also assume that the conductivity of water is important to 
salamander physiology because it is related to the concentration of 
ions in the water. Increased conductivity is associated with increased 
water contamination and decreased Eurycea abundance (Willson and Dorcas 
2003, pp. 766-768; Bowles et al. 2006, pp. 117-118). The lower limit of 
conductivity in developed Jollyville Plateau salamander sites where 
salamander densities were lower was 800 [micro]S cm-1 
(Bowles et al. 2006, p. 117). Salamanders were significantly more 
abundant at undeveloped sites where water conductivity averaged 600 
[micro]S cm-1 (Bowles et al. 2006, p. 117). Although one 
laboratory study on the related San Marcos salamander demonstrated that 
conductivities up to 2738 [micro]S cm-1 had no measurable 
effect on adult activity (Woods and Poteet 2006, p. 5), it remains 
unclear how elevated water conductance might affect juveniles or the 
long-term health of salamanders in the wild. In the absence of better 
information on the sensitivity of salamanders to changes in 
conductivity (or other contaminants), it is reasonable to assume that 
salamander survival, growth, and reproduction will be most successful 
when water quality is unaltered from natural aquifer conditions.
    Therefore, based on the information above, we identify aquatic 
invertebrates and water from the Northern Segment of the Edwards 
Aquifer, including adequate dissolved oxygen concentration, water 
conductance, and water temperature, to be essential components of the 
physical or biological features essential for the conservation of this 
species.
Cover or Shelter
Austin Blind Salamander
    The Austin blind salamander likely spends most of its life below 
the surface in the aquifer, and may only be flushed to the surface 
accidentally (Hillis et al. 2001, p. 273). While on the surface near 
spring outlets, they move into interstitial spaces (empty voids between 
rocks) within the substrate, using these

[[Page 50808]]

spaces for foraging habitat and cover from predators similar to other 
Eurycea salamanders in central Texas (Cole 1995, p. 24; Pierce and Wall 
2011, pp. 16-17). The surface is believed to be important as a source 
of food for this primarily subterranean species. These spaces should be 
free from sediment, as sediment fills interstitial spaces, eliminating 
resting places and also reducing habitat of the prey base (small 
aquatic invertebrates) (O'Donnell et al. 2006, p. 34). Austin blind 
salamanders have been observed under rocks and vegetation (Dries 2011, 
pers. comm.).
    Therefore, based on the information above, we identify rocky 
substrate, consisting of boulder, cobble, and gravel, with interstitial 
space that is free from sediment, to be an essential component of the 
physical or biological features essential for the conservation of this 
species.
Jollyville Plateau Salamander
    Similar to other Eurycea salamanders in central Texas, Jollyville 
Plateau salamanders move an unknown depth into the interstitial spaces 
(empty voids between rocks) within the substrate, using these spaces 
for foraging habitat and cover from predators (Cole 1995, p. 24; Pierce 
and Wall 2011, pp. 16-17). These spaces should be free from sediment, 
as sediment fills interstitial spaces, eliminating resting places and 
also reducing habitat of the prey base (small aquatic invertebrates) 
(O'Donnell et al. 2006, p. 34).
    Jollyville Plateau salamanders have been observed under rocks, leaf 
litter, and other vegetation (Bowles et al. 2006, pp. 114-116). There 
was a strong positive relationship between salamander abundance and the 
amount of available rocky substrate (Bowles et al. 2006, p. 114).
    Therefore, based on the information above, we identify rocky 
substrate, consisting of boulder, cobble, and gravel, with interstitial 
space that is free from sediment, to be an essential component of the 
physical or biological features essential for the conservation of this 
species.
Georgetown Salamander
    Similar to other Eurycea salamanders in central Texas, Georgetown 
salamanders move an unknown depth into the interstitial spaces (empty 
voids between rocks) within the substrate, using these spaces for 
foraging habitat and cover from predators (Cole 1995, p. 24; Pierce and 
Wall 2011, pp. 16-17). These spaces should be free from sediment, as 
sediment fills interstitial spaces, eliminating resting places and also 
reducing habitat of the prey base (small aquatic invertebrates) 
(O'Donnell et al. 2006, p. 34).
    Georgetown salamanders have been observed under rocks, leaf litter, 
woody debris, and other cover objects (Pierce et al. 2010, p. 295). 
There is evidence that these salamanders prefer large rocks over other 
cover objects (Pierce et al. 2010, p. 295), which is consistent with 
other studies on Eurycea habitat (Bowles et al. 2006, p. 114).
    Therefore, based on the information above, we identify rocky 
substrate, consisting of boulder, cobble, and gravel, with interstitial 
space that is free from sediment, to be an essential component of the 
physical or biological features essential for the conservation of this 
species.
Salado Salamander
    Because of its similarity to other Eurycea salamanders in central 
Texas, we assume that the Salado salamander spends some proportion of 
its life below the surface between rocks. Eurycea salamanders move an 
unknown depth into the interstitial spaces (empty voids between rocks) 
within the substrate, using these spaces for foraging habitat and cover 
from predators (Cole 1995, p. 24; Pierce and Wall 2011, pp. 16-17). 
These spaces should be free from sediment, as sediment fills 
interstitial spaces, eliminating resting places and also reducing 
habitat of the prey base (small aquatic invertebrates) (O'Donnell et 
al. 2006, p. 34).
    Salado salamanders have been observed under cover objects, such as 
rocks (Gluesenkamp 2011a, pers. comm.). Although no study has 
demonstrated the substrate preference of the Salado salamander, we 
assume that this species prefers large rocks over other cover objects, 
similar to other closely related Eurycea salamanders. Larger rocks 
provide more suitable interstitial spaces for foraging and cover.
    Therefore, based on the information above, we identify rocky 
substrate, consisting of boulder, cobble, and gravel, with interstitial 
space that is free from sediment, to be an essential component of the 
physical or biological features essential for the conservation of this 
species.
Sites for Breeding, Reproduction, or Rearing (or Development) of 
Offspring
Austin Blind Salamander
    Little is known about the reproductive habits of this species. 
However, the Austin blind salamander is fully aquatic, and therefore 
spends all of its life cycles in aquifer and spring waters. Eggs of 
central Texas Eurycea are rarely seen on the surface, so it is widely 
assumed that eggs are laid underground (Gluesenkamp 2011a, pers. comm.; 
Bendik 2011b, pers. comm.). Most Austin blind salamanders found on the 
surface are juveniles (Hillis et al. 2001, p. 267).
Jollyville Plateau Salamander
    Little is known about the reproductive habits of this species. 
However, the Jollyville Plateau salamander is fully aquatic, and 
therefore spends all of its life cycles in aquifer and spring waters. 
Eggs of central Texas Eurycea are rarely seen on the surface, so it is 
widely assumed that eggs are laid underground (Gluesenkamp 2011a, pers. 
comm.; Bendik 2011b, pers. comm.).
Georgetown Salamander
    Little is known about the reproductive habits of this species. 
However, the Georgetown salamander is fully aquatic, and therefore 
spends all of its life cycles in aquifer and spring waters. Eggs of 
central Texas Eurycea are rarely seen on the surface, so it is widely 
assumed that eggs are laid underground (Gluesenkamp 2011a, pers. comm.; 
Bendik 2011b, pers. comm.).
Salado Salamander
    Little is known about the reproductive habits of this species. 
However, the Salado salamander is fully aquatic, and therefore spends 
all of its life cycles in aquifer and spring waters. Eggs of central 
Texas Eurycea are rarely seen on the surface, so it is widely assumed 
that eggs are laid underground (Gluesenkamp 2011a, pers. comm.; Bendik 
2011b, pers. comm.).
Primary Constituent Elements for the Four Central Texas Salamanders
    Under the Act and its implementing regulations, we are required to 
identify the physical or biological features essential to the 
conservation of the salamander species in areas occupied at the time of 
listing, focusing on the features' primary constituent elements. We 
consider primary constituent elements to be the elements of physical or 
biological features that are essential to the conservation of the 
species.
    Based on our current knowledge of the physical or biological 
features and habitat characteristics required to sustain the species' 
life-history processes, we determine that the primary constituent 
elements specific to these salamander species are surface springs, 
underground streams, and wet caves containing:
Austin Blind Salamander
    1. Water from the Barton Springs Segment of the Edwards Aquifer. 
The

[[Page 50809]]

groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Austin blind salamander's prey base). Hydrologic regimes 
similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow from the spring sites and 
continuous flow in the subterranean habitat. The water chemistry must 
be similar to natural aquifer conditions, with temperatures between 
67.8 and 72.3[emsp14][deg]F (19.9 and 22.4 [deg]C), dissolved oxygen 
concentrations between 5 and 7 mg L-1, and specific water 
conductance between 605 and 740 [micro]S cm-1.
    2. Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat should be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
should have minimal sedimentation.
    3. Aquatic invertebrates for food. The spring and cave environments 
should be capable of supporting a diverse aquatic invertebrate 
community that includes crustaceans and insects.
    4. Subterranean aquifer. During periods of drought or dewatering on 
the surface in and around spring sites, access to the subsurface water 
table must exist to provide shelter and protection.
Jollyville Plateau Salamander
    1. Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Jollyville Plateau salamander's prey base). Hydrologic 
regimes similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow in subterranean habitats. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 65.3 
and 67.3 [deg]F (18.5 and 19.6 [deg]C), dissolved oxygen concentrations 
between 5.6 and 7.1 mg L-1, and specific water conductance 
between 550 and 625 [mu]S cm-1.
    2. Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat should be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
should have minimal sedimentation.
    3. Aquatic invertebrates for food. The spring and cave environments 
should be capable of supporting a diverse aquatic invertebrate 
community that includes crustaceans and insects.
    4. Subterranean aquifer. During periods of drought or dewatering on 
the surface in and around spring sites, access to the subsurface water 
table must exist to provide shelter and protection.
Georgetown Salamander
    1. Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Georgetown salamander's prey base). Hydrologic regimes 
similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow for subterranean sites. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 68.4 
and 69.8 [deg]F (20.2 and 21.0 [deg]C), dissolved oxygen concentrations 
between 6 and 8 mg L-1, and specific water conductivity 
between 604 and 721 [mu]S cm-1.
    2. Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat should be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
should have minimal sedimentation.
    3. Aquatic invertebrates for food. The spring and cave environments 
should be capable of supporting a diverse aquatic invertebrate 
community that includes crustaceans and insects.
    4. Subterranean aquifer. During periods of drought or dewatering on 
the surface in and around spring sites, access to the subsurface water 
table must exist to provide shelter and protection.
Salado Salamander
    1. Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Salado salamander's prey base). Hydrologic regimes 
similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow for subterranean sites. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 65.3 
and 69.8 [deg]F (18.5 and 21.0 [deg]C), dissolved oxygen concentrations 
between 5.6 and 8 mg L-1, and conductivity between 550 and 
721 [mu]S cm-1. The best scientific evidence available 
suggests that the groundwater of Salado salamander habitat is the same 
as Georgetown and Jollyville Plateau salamander habitat in terms of 
chemistry. Therefore, we include here for the Salado salamander the 
range of water chemistry parameters that encompass the ranges found in 
Jollyville and Georgetown salamander habitats.
    2. Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat should be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
should have minimal sedimentation.
    3. Aquatic invertebrates for food. The spring and cave environments 
should be capable of supporting a diverse aquatic invertebrate 
community that includes crustaceans and insects.
    4. Subterranean aquifer. During periods of drought or dewatering on 
the surface in and around spring sites, access to the subsurface water 
table should be provided for shelter and protection.
    With this proposed designation of critical habitat, we intend to 
identify the physical or biological features essential to the 
conservation of the species, through the identification of the primary 
constituent elements sufficient to support the life-history processes 
of the species. All units and subunits

[[Page 50810]]

proposed to be designated as critical habitat are currently occupied by 
one of the four salamander species and contain the primary constituent 
elements sufficient to support the life-history needs of the species.

Special Management Considerations or Protection

    When designating critical habitat, we assess whether the specific 
areas within the geographical area occupied by the species at the time 
of listing contain features which are essential to the conservation of 
the species and which may require special management considerations or 
protection. The features essential to the conservation of this species 
may require special management considerations or protection to reduce 
the following threats: Water quality degradation from contaminants, 
alteration to natural flow regimes, and physical habitat modification.
    For these salamanders, special management considerations or 
protection are needed to address threats. Management activities that 
could ameliorate threats include (but are not limited to): (1) 
Protecting the quality of cave and spring water by implementing 
comprehensive programs to control and reduce point sources and non-
point sources of pollution throughout the Barton Springs and Northern 
Segments of the Edwards Aquifer, (2) minimizing the likelihood of 
pollution events that would affect groundwater quality, (3) protecting 
groundwater and spring flow quantity (for example, by implementing 
water conservation and drought contingency plans throughout the Barton 
Springs and Northern Segments), and (4) excluding cattle and feral hogs 
through fencing to protect spring habitats from damage.

Criteria Used To Identify Critical Habitat

    As required by section 4(b)(1)(A) of the Act, we use the best 
scientific data available in determining areas that contain the 
features that are essential to the conservation of the Austin blind, 
Jollyville Plateau, Georgetown, and Salado salamanders. During our 
preparation for proposing critical habitat for the four salamander 
species, we have reviewed: (1) Data for historical and current 
occurrence, (2) information pertaining to habitat features essential 
for the conservation of these species, and (3) scientific information 
on the biology and ecology of the four species. We have also reviewed a 
number of studies and surveys of the four salamander species that 
confirm historical and current occurrence of the four species 
including, but not limited to, Sweet (1978; 1982), COA (2001), 
Chippindale et al. (2000), and Hillis et al. (2001). Finally, 
salamander site locations and observations were verified with the aid 
of salamander biologists, museum collection records, and site visits.
    In accordance with the Act and its implementing regulation at 50 
CFR 424.12(e), we consider whether designating additional areas--
outside those currently occupied as well as those occupied at the time 
of listing--are necessary to ensure the conservation of the species. We 
are not currently proposing to designate any additional areas outside 
the geographical area occupied by the species, because the occupied 
habitats proposed for critical habitat are sufficient for the 
conservation of the species. For the purpose of designating critical 
habitat for the four central Texas salamander species, we define an 
area as occupied based upon the reliable observation of a salamander 
species by a knowledgeable scientist. It is very difficult to prove 
unquestionably that a salamander population has been extirpated from a 
spring site due to these species' ability to occupy the inaccessible 
subsurface habitat. We therefore considered any site that had a 
salamander observation at any point in time currently occupied, unless 
that spring or cave site had been destroyed.
    Based on our review, the proposed critical habitat areas described 
below constitute our best assessment at this time of areas that are 
within the geographical range occupied by at least one of the four 
salamander species, and are considered to contain features essential to 
the conservation of these species. The extent to which the subterranean 
populations of these species exist belowground away from outlets of the 
spring system is unknown. Because the hydrology of central Texas is 
very complex and information on the hydrology of specific spring sites 
are largely unknown, we will be seeking information on spring hydrology 
and salamander underground distribution during our public comment 
period (see DATES). However, at the time of this proposed listing rule, 
the best scientific evidence available suggests that the population of 
these salamanders can extend at least 984 ft (300 m) from the spring 
opening through underground conduits.
    We are proposing for designation of critical habitat lands that we 
have determined are occupied by at least one of the four salamanders 
and contain sufficient elements of physical or biological features to 
support life-history processes essential for the conservation of the 
species. We delineated both surface and subsurface critical habitat 
components. The surface critical habitat component was delineated by 
starting with the cave or spring point locations that are occupied by 
the salamanders and extending a line downstream 164 ft (50 m) because 
this is the farthest a salamander has been observed from a spring 
outlet. The surface critical habitat includes the spring outlets and 
outflow up to the high water line and 164 ft (50 m) of downstream 
habitat, but does not include manmade structures (such as buildings, 
aqueducts, runways, roads, and other paved areas); however, the 
subterranean aquifer may extend below such structures. We delineated 
the subsurface critical habitat unit boundaries by starting with the 
cave or spring point locations that are occupied by the salamanders. 
From these cave or springs points, we delineated a 984-ft (300-m) 
buffer to create the polygons that capture the extent to which we 
believe the salamander populations exist through underground conduits. 
The polygons were then simplified to reduce the number of vertices, but 
still retain the overall shape and extent. Once that was done, polygons 
that were within 98 ft (30 m) of each other were merged together 
because these areas are likely connected underground. Each new merged 
polygon was then revised by removing extraneous divits or protrusions 
that resulted from the merge process.
    When determining proposed critical habitat boundaries, we made 
every effort to avoid including developed areas, such as lands covered 
by buildings, pavement, and other structures, because such lands lack 
physical or biological features essential for the conservation of the 
four central Texas salamanders. The scale of the maps we prepared under 
the parameters for publication within the Code of Federal Regulations 
may not reflect the exclusion of such developed lands. Any such lands 
inadvertently left inside critical habitat boundaries shown on the maps 
of this proposed rule have been excluded by text in the proposed rule, 
and are not proposed for designation as critical habitat. Therefore, if 
the critical habitat is finalized as proposed, a Federal action 
involving these lands would not trigger section 7 consultation with 
respect to critical habitat and the requirement of no adverse 
modification unless the specific action would affect the physical or 
biological features in the underground or adjacent critical habitat.
    The critical habitat designation is defined by the map or maps, as

[[Page 50811]]

modified by any accompanying regulatory text, presented at the end of 
this document in the rule portion. We include more detailed information 
on the boundaries of the critical habitat designation in the preamble 
of this document. We will make the coordinates or plot points or both 
on which each map is based available to the public on http://regulations.gov at Docket No. FWS-R2-ES-2012-0035, on our Internet site 
at http://www.fws.gov/southwest/es/AustinTexas/, and at the field 
office responsible for the designation (see FOR FURTHER INFORMATION 
CONTACT above).

Proposed Critical Habitat Designation

    We are proposing a total of 52 units for designation for the 4 
central Texas salamanders based on sufficient elements of physical or 
biological features being present to support the Austin blind, 
Jollyville Plateau, Georgetown, and Salado salamanders' life-history 
processes. Some units contain all of the identified elements of 
physical or biological features and support multiple life-history 
processes. Some units contain only some elements of the physical or 
biological features necessary to support the four central Texas 
salamanders' particular use of that habitat. In some units, the 
physical or biological features essential for the conservation of these 
salamanders have been impacted at times, and in some cases these 
impacts have had negative effects on the salamander populations there. 
We recognize that some units have experienced impacts and may have 
physical or biological features of lesser quality than others. Special 
management or protection is needed at these sites to restore the 
physical or biological features to provide for long-term sustainability 
of the species at these sites. In addition, high-quality sites need 
special protection, and in some cases management, to maintain their 
quality and ability to sustain the salamander populations over the long 
term.
    We are proposing 1 unit as critical habitat for the Austin blind 
salamander, 33 units as critical habitat for the Jollyville Plateau 
salamander, 14 units as critical habitat for the Georgetown salamander, 
and 4 units as critical habitat for the Salado salamander (52 units 
total). The critical habitat areas we describe below constitute our 
current best assessment of areas that meet the definition of critical 
habitat for the four salamander species. As previously noted, we are 
proposing both surface and subsurface critical habitat components. The 
surface critical habitat includes the spring outlets and outflow up to 
the high water line and 164 ft (50 m) of downstream habitat, but does 
not include manmade structures (such as buildings, aqueducts, runways, 
roads, and other paved areas); however, the subterranean aquifer may 
extend below such structures. The subsurface critical habitat includes 
underground features in a circle with a radius of 984 ft (300 m) around 
the springs. The 52 units we propose as critical habitat are listed and 
described below, and acreages are based on the size of the subsurface 
critical habitat component. All units described below are occupied by 
one of the four salamander species.

                     Table 7--Proposed Critical Habitat Unit for the Austin Blind Salamander
----------------------------------------------------------------------------------------------------------------
          Critical habitat unit               Land ownership by type        Size of unit in acres  (hectares)
----------------------------------------------------------------------------------------------------------------
1. Barton Springs Unit...................  City, Private...............  120 (49).
                                                                        ----------------------------------------
    Total................................  ............................  120 ac (49 ha).
----------------------------------------------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding. Area estimates reflect all land within critical habitat unit
  boundaries.


                 Table 8--Proposed Critical Habitat Units for the Jollyville Plateau Salamander
----------------------------------------------------------------------------------------------------------------
          Critical habitat unit               Land ownership by type        Size of unit in acres  (hectares)
----------------------------------------------------------------------------------------------------------------
1. Krienke Spring Unit...................  Private.....................  68 (28).
2. Brushy Creek Spring Unit..............  Private.....................  68 (28).
3. Testudo Tube Cave Unit................  Private, City...............  68 (28).
4. Buttercup Creek Cave Unit.............  Private.....................  227 (92).
5. Treehouse Cave Unit...................  Private.....................  68 (28).
6. Avery Spring Unit.....................  Private.....................  237 (96).
7. PC Spring Unit........................  Private.....................  68 (28).
8. Baker and Audubon Spring Unit.........  Private.....................  110 (45).
9. Wheless Spring Unit...................  Private, County.............  135 (55).
10. Blizzard R-Bar-B Spring Unit.........  Private.....................  68 (28).
11. House Spring Unit....................  Private.....................  68 (28).
12. Kelly Hollow Spring Unit.............  Private.....................  68 (28).
13. MacDonald Well Unit..................  Private, County.............  68 (28).
14. Kretschmarr Unit.....................  Private, County.............  112 (45).
15. Pope and Hiers (Canyon Creek) Spring   Private.....................  68 (28).
 Unit.
16. Fern Gully Spring Unit...............  Private, City...............  68 (28).
17. Bull Creek 1 Unit....................  Private, City, County.......  1,157 (468).
18. Bull Creek 2 Unit....................  Private, City, County.......  237 (96).
19. Bull Creek 3 Unit....................  Private, City...............  254 (103).
20. Moss Gulley Spring Unit..............  City, County................  68 (28).
21. Ivanhoe Spring Unit..................  City........................  68 (28).
22. Sylvia Spring Unit...................  Private, City, County.......  103 (42).
23. Tanglewood Spring Unit...............  Private.....................  68 (28).
24. Long Hog Hollow Unit.................  Private.....................  68 (28).
25. Tributary 3 Unit.....................  Private.....................  68 (28).
26. Sierra Spring Unit...................  Private.....................  68 (28).
27. Troll Spring Unit....................  Private.....................  98 (40).
28. Stillhouse Unit......................  Private.....................  203 (82).

[[Page 50812]]

 
29. Salamander Cave Unit.................  Private.....................  68 (28).
30. Indian Spring Unit...................  Private.....................  68 (28).
31. Spicewood Spring Unit................  Private.....................  68 (28).
32. Balcones District Park Spring Unit...  Private, City...............  68 (28).
33. Tributary 4 Unit.....................  Private, City...............  159 (64).
                                                                        ----------------------------------------
    Total................................  ............................  4,460 ac (1,816 ha).
----------------------------------------------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding. Area estimates reflect all land within critical habitat unit
  boundaries.


                     Table 9--Proposed Critical Habitat Units for the Georgetown Salamander
----------------------------------------------------------------------------------------------------------------
          Critical habitat unit               Land ownership by type         Size of unit in acres (hectares)
----------------------------------------------------------------------------------------------------------------
1. Cobb Unit.............................  Private.....................  83 (34)
2. Cowen Creek Spring Unit...............  Private.....................  68 (28).
3. Bat Well Unit.........................  Private.....................  68 (28).
4. Walnut Spring Unit....................  Private, County.............  68 (28).
5. Twin Springs Unit.....................  Private, County.............  68 (28).
6. Hogg Hollow Spring Unit...............  Private, Federal............  68 (28).
7. Cedar Hollow Spring Unit..............  Private.....................  68 (28).
8. Lake Georgetown Unit..................  Federal, Private............  132 (53).
9. Water Tank Cave Unit..................  Private.....................  68 (28).
10. Avant Spring Unit....................  Private.....................  68 (28).
11. Buford Hollow Spring Unit............  Federal, Private............  68 (28).
12. Swinbank Spring Unit.................  City, Private...............  68 (28).
13. Shadow Canyon Unit...................  City, Private...............  68 (28).
14. San Gabriel Springs Unit.............  City........................  68 (28).
                                                                        ----------------------------------------
    Total................................  ............................  1,031 ac (423 ha).
----------------------------------------------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding. Area estimates reflect all land within critical habitat unit
  boundaries.


                       Table 10--Proposed Critical Habitat Units for the Salado Salamander
----------------------------------------------------------------------------------------------------------------
          Critical habitat unit               Land ownership by type         Size of unit in acres (hectares)
----------------------------------------------------------------------------------------------------------------
1. Hog Hollow Spring Unit................  Private.....................  68 (28)
2. Solana Spring 1 Unit.........  Private.....................  68 (28).
3. Cistern Spring Unit...................  Private.....................  68 (28).
4. IH-35 Unit............................  Private, State, City........  168 (68).
                                                                        ----------------------------------------
    Total................................  ............................  372 ac (152 ha).
----------------------------------------------------------------------------------------------------------------
Note: Area sizes may not sum due to rounding. Area estimates reflect all land within critical habitat unit
  boundaries.

    We present brief descriptions of all units, and reasons why they 
meet the definition of critical habitat for the four central Texas 
salamanders, below.

Austin Blind Salamander

Unit 1: Barton Springs Unit
    The Barton Springs Unit consists of 120 ac (49 ha) of City and 
private land in the City of Austin, central Travis County, Texas. Most 
of the unit is located in Zilker Park, which is owned by the City of 
Austin. Most of the unit consists of landscaped areas managed as a 
public park. The southwestern portion of the unit is dense commercial 
development, and part of the southern portion contains residential 
development. Barton Springs Road, a major roadway, crosses the 
northeastern portion of the unit. This unit contains Parthenia Spring, 
Sunken Gardens Spring, and Eliza Spring, which are occupied by Austin 
blind salamander. The springs are located in the Barton Creek 
watershed. Parthenia Spring is located in the backwater of Barton 
Springs Pool, which is formed by a dam on Barton Creek; Eliza Spring is 
on an unnamed tributary to the bypass channel of the pool; and Sunken 
Gardens Spring is located on a tributary that enters Barton Creek 
downstream of the dam for Barton Springs Pool. The unit contains all of 
the primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
contributing and recharge zone for the Barton Springs segment of the 
Edwards Aquifer and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the underground aquifer in this 
area and the springs and fissure outlets. The unit was further 
delineated by drawing a circle with a radius of 984 ft (300 m) around 
the springs, representing the extent of the subterranean critical 
habitat. We joined the edges of the resulting circles. Because we did 
not have specific points for species locations, we used the center of 
Eliza and Sunken Gardens springs and the southwestern point of a 
fissure in Parthenia Springs.

[[Page 50813]]

Jollyville Plateau Salamander

Unit 1: Krienke Spring Unit
    Unit 1 consists of 68 ac (28 ha) of private land in southern 
Williamson County, Texas. The unit is located just south of State 
Highway 29. The northern part of the unit is in dense residential 
development, while the southern part of the unit is less densely 
developed. County Road 175 (Sam Bass Road) crosses the northern half of 
the unit. This unit contains Krienke Spring, which is occupied by the 
Jollyville Plateau salamander. The spring is located on an unnamed 
tributary of Dry Fork, a tributary to Brushy Creek. The unit contains 
all the primary constituent elements essential for the conservation of 
the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 2: Brushy Creek Spring Unit
    Unit 2 consists of 68 ac (28 ha) of private land in southern 
Williamson County, Texas. The unit is centered just south of Palm 
Valley Boulevard and west of Grimes Boulevard. The northern part of the 
unit is covered with commercial and residential development, while the 
southern part is less densely developed. Some areas along the stream 
are undeveloped. This unit contains Brushy Creek Spring, which is 
occupied by the Jollyville Plateau salamander. The spring is near 
Brushy Creek. The unit contains all the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 3: Testudo Tube Cave Unit
    Unit 3 consists of 68 ac (28 ha) of City of Austin and private land 
in southern Williamson County and northern Travis County, Texas. The 
unit is located just east of Lime Creek Road. The unit is mostly 
undeveloped but several unpaved roads cross it. This unit contains 
Testudo Tube Cave, which is occupied by the Jollyville Plateau 
salamander. The cave and the surrounding area are owned by the City of 
Austin as water quality protection land. The cave contains the Tooth 
Cave ground beetle (Rhadine persephone), an endangered karst 
invertebrate. As part of the mitigation for the Lakeline Mall HCP, the 
cave must be protected and managed in perpetuity. These actions will 
provide some benefit to the Jollyville Plateau salamander. The unit 
contains all the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the cave. The unit was further 
delineated by drawing a circle with a radius of 984 ft (300 m) around 
the cave, representing the extent of the subterranean critical habitat.
Unit 4: Buttercup Creek Cave Unit
    Unit 4 consists of 227 ac (92 ha) of private land in southern 
Williamson County, Texas. The unit is located east and south of the 
intersection of Lakeline Boulevard and Buttercup Creek Boulevard. The 
unit is mostly covered with residential property. Lakeline Boulevard, a 
major thoroughfare, crosses the northeast area of the unit. An 
undeveloped area of parks and setbacks is in the south central part of 
the unit. This unit contains four caves: TWASA Cave, Illex Cave, 
Buttercup Creek Cave, and Flea Cave, which are occupied by the 
Jollyville Plateau salamander. The three latter caves are located in a 
preserve set up as mitigation property under the Buttercup HCP. The HCP 
covers adverse impacts to the Tooth Cave ground beetle. Although the 
salamander is not covered under the Buttercup HCP, the protection 
afforded these caves by the HCP provides some benefit for the species. 
The unit contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Buttercup HCP, and impacts to the Tooth Cave ground beetle 
are permitted (Service 1999, p. 1). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the caves. The unit was further 
delineated by drawing a circle with a radius of 984 ft (300 m) around 
the caves, representing the extent of the subterranean critical 
habitat. We joined the edges of the resulting circles.
Unit 5: Treehouse Cave Unit
    Unit 5 consists of 68 ac (28 ha) of private land in southern 
Williamson County, Texas. The unit is located east of the intersection 
of Buttercup Creek Boulevard and Sycamore Drive. Most of the unit is 
covered with moderately dense residential development. A small park is 
close to the center of the unit, and a greenbelt crosses the unit from 
east to west. This unit contains Treehouse Cave, which is occupied by 
the Jollyville Plateau salamander. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the cave. The unit was further 
delineated by drawing a circle with a radius of 984 ft (300 m) around 
the cave, representing the extent of the subterranean critical habitat.
Unit 6: Avery Spring Unit
    Unit 6 consists of 237 ac (96 ha) of private land in southern 
Williamson County, Texas. The unit is located north of Avery Ranch 
Boulevard and west of Parmer Lane. The unit has large areas covered by 
residential development. The developed areas are separated by fairways 
and greens of a golf course. This unit contains three springs: Avery 
Springhouse Spring, Hill Marsh Spring, and Avery Deer Spring, which are 
occupied by the Jollyville Plateau salamander. The springs are located 
on an unnamed tributary to South Brushy Creek. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater

[[Page 50814]]

pollution from current and future development in the watershed, 
potential for vandalism, and depletion of groundwater (see Special 
Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the three springs, representing the extent of the 
subterranean critical habitat. We joined the edges of the resulting 
circles.
Unit 7: PC Spring Unit
    Unit 7 consists of 68 ac (28 ha) of private and public land in 
southern Williamson County, Texas. State Highway 45, a major toll road, 
crosses the north central part of the unit from east to west, and Ranch 
to Market Road 620 goes under it midway between the center and the 
western edge. Except for roadways, the unit is undeveloped. This unit 
contains PC Spring, which is occupied by the Jollyville Plateau 
salamander. The spring is located on Davis Spring Branch. The unit 
contains the primary constituent elements essential for the 
conservation of species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 8: Baker and Audubon Spring Unit
    Unit 8 consists of 110 ac (45 ha) of private and Lower Colorado 
River Authority (LCRA) land in northern Travis County, Texas. The unit 
is located south of Lime Creek Road and southwest of the intersection 
of Canyon Creek Drive and Lime Springs Road. The unit is wooded, 
undeveloped, and owned by Travis Audubon Society and LCRA. The entire 
unit is managed as part of the Balcones Canyonlands HCP. This unit 
contains two springs, Baker Spring and Audubon Spring, which are 
occupied by the Jollyville Plateau salamander. The springs are in the 
drainage of an unnamed tributary to Cypress Creek. The unit contains 
the primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Balcones Canyonlands Preserve HCP, and impacts to 35 species 
are permitted (Service 1996b, p. 3). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.
Unit 9: Wheless Spring Unit
    Unit 9 consists of 135 ac (55 ha) of private LCRA and Travis County 
land in northern Travis County, Texas. The unit is located about 0.8 mi 
(1.3 km) west of Grand Oaks Loop. The unit is wooded and consists of 
totally undeveloped land owned by LCRA and The Nature Conservancy. The 
unit is managed as part of the Balcones Canyonlands Preserve HCP. An 
unpaved road crosses the unit from north to south. This unit contains 
two springs, Wheless Spring and Spring 25, which are occupied by the 
Jollyville Plateau salamander. The springs are in the Long Hollow Creek 
drainage. The unit contains the primary constituent elements essential 
for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, habitat disturbance by feral hogs, 
and depletion of groundwater (see Special Management Considerations or 
Protection section). The unit is within the Balcones Canyonlands 
Preserve HCP, and impacts to 35 species are permitted (Service 1996b, 
p. 3). However, impacts to the Jollyville Plateau salamander are not 
covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.
Unit 10: Blizzard R-Bar-B Spring Unit
    Unit 10 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is located west of Grand Oaks Loop. The 
extreme eastern portion of the unit is on the edge of residential 
development; a golf course (Twin Springs) crosses the central portion; 
and the remainder is wooded and undeveloped. This unit contains 
Blizzard R-Bar-B Spring, which is occupied by the Jollyville Plateau 
salamander. The spring is located on Cypress Creek. The unit contains 
the primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 11: House Spring Unit
    Unit 11 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is located just north of Benevento Way 
Road. Dies Ranch Road crosses the extreme eastern part of the unit. The 
entire unit is covered with dense residential development except for a 
narrow corridor along the stream, which crosses the unit from north to 
south. Several streets are located in the unit. This unit contains 
House Spring, which is occupied by the Jollyville Plateau salamander. 
The spring is located on an unnamed tributary to Lake Marble Falls. The 
unit contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 12: Kelly Hollow Spring Unit
    Unit 12 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is located southeast of the intersection 
of Anderson Mill Road and Farm to Market Road 2769. With

[[Page 50815]]

the exception of a portion of Anderson Mill Road along the northern 
edge of the unit, this unit is primarily undeveloped woodland. This 
unit contains Kelly Hollow Spring, which is occupied by the Jollyville 
Plateau salamander. The spring is located on an unnamed tributary to 
Lake Marble Falls. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 13: MacDonald Well Unit
    Unit 13 consists of 68 ac (28 ha) of private and Travis County land 
in northern Travis County, Texas. The unit is centered near the 
intersection of Grand Oaks Loop and Farm to Market Road 2769. Farm to 
Market Road 2769 crosses the unit slightly north of its center. The 
northern portion of the unit contains residential development and part 
of Twin Creeks Golf Course. This unit contains MacDonald Well, which is 
occupied by the Jollyville Plateau salamander. The spring is located on 
an unnamed tributary to Lake Marble Falls. The unit contains the 
primary constituent elements essential for the conservation of the 
species. The spring and adjacent land are protected and monitored as 
part of the Balcones Canyonlands Preserve HCP.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Balcones Canyonlands Preserve HCP, and impacts to 35 species 
are permitted (Service 1996b, p. 3). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 14: Kretschmarr Unit
    Unit 14 consists of 112 ac (45 ha) of private and Travis County 
land in northern Travis County, Texas. The unit is located west of 
Ranch to Market Road 620. Wilson Parke Avenue crosses the unit along 
its southern border. Most of the unit is undeveloped, with one 
commercial development near the west central portion. Some of the unit 
is owned and managed by Travis County as part of the Balcones 
Canyonlands Preserve. This unit contains three springs: Kretschmarr 
Salamander Cave, Unnamed Tributary Downstream of Grandview, and SAS 
Canyon, which are occupied by the Jollyville Plateau salamander. The 
unit contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We connected the edges of the resulting circles.
Unit 15: Pope and Hiers (Canyon Creek) Spring Unit
    Unit 15 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is located between Bramblecrest Drive 
and Winchelsea Drive. The unit contains dense residential development 
on its northern, eastern, and western portions. The central portion of 
the unit is an undeveloped canyon and is preserved in perpetuity as 
part of a private preserve. This unit contains Canyon Creek Pope and 
Hiers Spring, which is occupied by the Jollyville Plateau salamander. 
The spring is located on Bull Creek Tributary 6. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 16: Fern Gully Spring Unit
    Unit 16 consists of 68 ac (28 ha) of private and City of Austin 
land in northern Travis County, Texas. The unit is centered just south 
of the intersection of Jenaro Court and Boulder Lane. The unit contains 
dense residential development on much of its northern half. Most of the 
southern half of the unit is undeveloped land managed by the City of 
Austin as part of the Balcones Canyonlands Preserve HCP, and a portion 
is part of the Canyon Creek preserve, a privately managed conservation 
area. This unit contains Fern Gully Spring, which is occupied by the 
Jollyville Plateau salamander. The spring is located on Bull Creek 
Tributary 5. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Balcones Canyonlands Preserve HCP, and impacts to 35 species 
are permitted (Service 1996b, p. 3). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 17: Bull Creek 1 Unit
    Unit 17 consists of 1,157 ac (468 ha) of private, City of Austin, 
and Travis County land in northern Travis County, Texas. The unit 
extends from the southeastern portion of Chestnut Ridge Road to 3M 
Center, just north of Ranch to Market Road 2222. The unit contains some 
residential development on the extreme edge of its northern portion and 
part of Vandegrift High School near its southeastern corner. Most of 
the remainder of the unit is undeveloped land managed by the City of 
Austin and Travis County as part of the Balcones Canyonlands Preserve 
HCP. This unit contains the following 34 springs: Tubb Spring, Broken 
Bridge Spring, Spring 17, Tributary No. 5, Tributary 6 at Sewage Line, 
Canyon Creek, Tributary No. 6, Gardens of Bull Creek, Canyon

[[Page 50816]]

Creek Hog Wallow Spring, Spring 5, Franklin, Pit Spring, Bull Creek 
Spring Pool, Spring 1, Spring 4, Spring 2, Lanier Spring, Cistern 
(Pipe) Spring, Spring 3, Lanier 90-foot Riffle, Bull Creek at Lanier 
Tract, Ribelin/Lanier, Spring 18, Horsethief, Ribelin, Spring 15, 
Spring 16, Spring 14, Lower Ribelin, Spring 13, Spring 12, Upper 
Ribelin, Spring 10, and Spring 9. These springs are occupied by the 
Jollyville Plateau salamander and are located on Bull Creek and its 
tributaries. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, habitat destruction by feral hogs, 
and depletion of groundwater (see Special Management Considerations or 
Protection section). The unit is within the Balcones Canyonlands 
Preserve HCP, and impacts to 35 species are permitted (Service 1996b, 
p. 3). However, impacts to the Jollyville Plateau salamander are not 
covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.
Unit 18: Bull Creek 2 Unit
    Unit 18 consists of 237 ac (96 ha) of private, City of Austin, and 
Travis County land in northern Travis County, Texas. The center of the 
unit is near the eastern end of Concordia University Drive. Concordia 
University is in the central and eastern parts of the unit. Much of the 
rest of the unit is undeveloped land managed by the City of Austin and 
Travis County as part of the Balcones Canyonlands Preserve HCP. This 
unit contains six springs: Schlumberger Spring No. 1, Schlumberger 
Spring No. 2, Schlumberger Spring No. 6, Schlumberger Spring No. 19, 
Concordia Spring X, and Concordia Spring Y, which are occupied by the 
Jollyville Plateau salamander. The springs are located on Bull Creek 
Tributary 7. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Balcones Canyonlands Preserve HCP, and impacts to 35 species 
are permitted (Service 1996b, p. 3). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.
Unit 19: Bull Creek 3 Unit
    Unit 19 consists of 254 ac (103 ha) of private and City of Austin 
land in northern Travis County, Texas. The unit is just southeast of 
the intersection of Ranch to Market Road 620 and Vista Parke Drive. The 
unit contains dense residential development on much of its northern 
half. Most of the rest of the unit (about 134 ac (54.2 ha)) is 
undeveloped land managed by as part of the Four Points HCP. Much of the 
remainder of the unit is managed by the City of Austin as part of the 
Balcones Canyonlands Preserve HCP. This unit contains five springs: 
Spring No. 21, Spring No. 22, Spring No. 24, Hamilton Reserve West, and 
Gaas Spring, which are occupied by the Jollyville Plateau salamander. 
The springs are located on Bull Creek. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets up to the high 
water line and 164 ft (50 m) of downstream habitat. The unit was 
further delineated by drawing a circle with a radius of 984 ft (300 m) 
around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles. Under 
section 4(b)(2) of the Act, certain lands in this unit are being 
considered for exclusion from the final rule for critical habitat (see 
Application of Section 4(b)(2) of the Act section below).
Unit 20: Moss Gulley Spring Unit
    Unit 20 consists of 68 ac (28 ha) of City of Austin and Travis 
County land in northern Travis County, Texas. The unit is just east of 
the eastern end of Unit 19. The unit is all undeveloped woodland, and 
all is managed by the City of Austin or Travis County as part of the 
Balcones Canyonlands Preserve HCP. This unit contains Moss Gulley 
Spring, which is occupied by the Jollyville Plateau salamander. The 
spring is located on Bull Creek. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section). The unit is 
within the Balcones Canyonlands Preserve HCP, and impacts to 35 species 
are permitted (Service 1996b, p. 3). However, impacts to the Jollyville 
Plateau salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 21: Ivanhoe Spring Unit
    Unit 21 consists of 68 ac (28 ha) of City of Austin land in 
northern Travis County, Texas. The unit is east of the northwest extent 
of High Hollow Drive. The unit is all undeveloped woodland, and is 
managed by the City of Austin as part of the Balcones Canyonlands 
Preserve HCP. This unit contains Ivanhoe Spring 2, which is occupied by 
the Jollyville Plateau salamander. The spring is located on West Bull 
Creek. The unit contains the primary constituent elements essential for 
the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, destruction of habitat by feral 
hogs, and depletion of groundwater (see Special Management 
Considerations or Protection section). The unit is within the Balcones 
Canyonlands Preserve HCP, and impacts to 35 species are permitted 
(Service 1996b, p. 3). However, impacts to the Jollyville Plateau 
salamander are not covered under this HCP.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.

[[Page 50817]]

Unit 22: Sylvia Spring Unit
    Unit 22 consists of 103 ac (42 ha) of private, City, and Williamson 
County land in northern Travis County and southwestern Williamson 
County, Texas. The unit is centered just east of the intersection 
Callanish Park Drive and Westerkirk Drive. The western, extreme 
northeastern, and extreme southern portions of the unit are residential 
development. An undeveloped stream corridor crosses the unit from north 
to south. This unit contains two springs: Small Sylvia Spring and 
Spicewood Valley Park Spring, which are occupied by the Jollyville 
Plateau salamander. The springs are located on an unnamed tributary to 
Tanglewood Creek. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.
Unit 23: Tanglewood Spring Unit
    Unit 23 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered north of the intersection of 
Spicewood Springs Road and Yaupon Drive. Spicewood Springs Road crosses 
the unit from southwest to east. Residential and commercial development 
is found in most of the unit except in a stream corridor in the central 
part of the unit. An undeveloped stream corridor crosses the unit from 
east to west. This unit contains Tanglewood Spring, which is occupied 
by the Jollyville Plateau salamander. The spring is located on 
Tanglewood Creek, a tributary to Bull Creek. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 24: Long Hog Hollow Unit
    Unit 24 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered east of the intersection of 
Cassia Drive and Fireoak Drive. Most of the unit is in residential 
development. There are wooded corridors in the central and eastern 
portion of the unit. This unit contains Long Hog Hollow Tributary, 
which is occupied by the Jollyville Plateau salamander. The spring is 
located on Long Hog Hollow Tributary. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 25: Tributary 3 Unit
    Unit 25 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered between Bluegrass Drive and 
Spicebush Drive. The eastern and western part of the unit is in 
residential development. There are wooded corridors in the central part 
of the unit, and scattered woodland in the eastern and western part. 
There is a golf course in the north-central part of the unit. This unit 
contains Tributary No. 3, which is occupied by the Jollyville Plateau 
salamander. The spring is located on Bull Creek Tributary 3. The unit 
contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 26: Sierra Spring Unit
    Unit 26 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is located west of the intersection of 
Tahoma Place and Ladera Vista Drive. The eastern and western part of 
the unit is in residential development. A wooded corridor crosses the 
central part of the unit from north to south. This unit contains Sierra 
Spring, which is occupied by the Jollyville Plateau salamander. The 
spring is located on Bull Creek Tributary 3. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 27: Troll Spring Unit
    Unit 27 consists of 98 ac (40 ha) of private land in northern 
Travis County, Texas. The unit is located west of the intersection of 
Jollyville Road and Taylor Draper Lane. The eastern and western part of 
the unit is in residential development. A wooded corridor crosses the 
central part of the unit from north to south. This unit contains two 
springs, Hearth Spring and Troll Spring, which are occupied by the 
Jollyville Plateau salamander. The springs are located on Bull Creek 
Tributary 3. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets up to the high 
water line and 164 ft (50 m) of downstream habitat. The unit was 
further delineated by drawing a circle with a radius of 984 ft (300 m) 
around the springs, representing the extent of the subterranean 
critical habitat. We

[[Page 50818]]

connected the edges of the resulting circles.
Unit 28: Stillhouse Unit
    Unit 28 consists of 203 ac (82 ha) of private land in northern 
Travis County, Texas. The unit is centered due north of the 
intersection of West Rim Drive and Burney Drive. The northern and 
southern part of the unit is in residential development. A wooded 
corridor crosses the central part of the unit from east to west. This 
unit contains seven springs: Barrow Hollow Spring, Spring 20, 
Stillhouse Hollow Tributary, Stillhouse Tributary, Little Stillhouse 
Hollow Spring, Stillhouse Hollow Spring, and Barrow Preserve Tributary. 
All are occupied by the Jollyville Plateau salamander. The springs are 
located on an unnamed tributary to Bull Creek. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflows 
up to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We connected the edges of the resulting circles.
Unit 29: Salamander Cave Unit
    Unit 29 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered near the southern end of 
Raintree Place, just north of Spicewood Springs Road. Most of the unit 
is covered with commercial and residential development, except for a 
small portion of wooded area near the center. A wooded corridor crosses 
the central part of the unit from east to west. This unit contains 
Salamander Cave, which is occupied by the Jollyville Plateau 
salamander. The spring is located on an unnamed tributary to Shoal 
Creek. The unit contains the primary constituent elements essential for 
the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 30: Indian Spring Unit
    Unit 30 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered just south of Greystone 
Drive about half way between its intersection with Edgerock Drive and 
Chimney Corners Drive. Most of the unit is covered with residential 
development except for a small wooded corridor that crosses the central 
part of the unit from east to west. This unit contains Indian Spring, 
which is occupied by the Jollyville Plateau salamander. The spring is 
located on an unnamed tributary to Shoal Creek. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 31: Spicewood Spring Unit
    Unit 31 consists of 68 ac (28 ha) of private land in northern 
Travis County, Texas. The unit is centered just northeast of the 
intersection of Ceberry Drive and Spicewood Springs Road, just 
downstream of the bridge on Ceberry Drive. Most of the unit is covered 
with commercial and residential development except for a small wooded 
corridor along the stream, which crosses the unit from north to east. 
This unit contains two springs, Spicewood Spring and Spicewood 
Tributary, which are occupied by the Jollyville Plateau salamander. The 
springs are located in an unnamed tributary to Shoal Creek. The unit 
contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 32: Balcones District Park Spring Unit
    Unit 32 consists of 68 ac (28 ha) of City of Austin and private 
land in northern Travis County, Texas. The unit is centered about 470 
yards (430 m) northeast of the intersection of Duval Road and Amherst 
Drive. Most of the unit is in a city park (Balcones Community Park) 
with a swimming pool. A substantial amount of the park is wooded and 
undeveloped. There is dense commercial development in the southern and 
southeastern portions of the unit. This unit contains Balcones District 
Park Spring, which is occupied by the Jollyville Plateau salamander. 
The spring is located in the streambed of an unnamed tributary to 
Walnut Creek. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat.
Unit 33: Tributary 4 Unit
    Unit 33 consists of 159 ac (64 ha) of private and City of Austin 
land in northern Travis County, Texas. The unit is located west of the 
intersection of Spicewood Springs Road and Old Lampasas Trail in the 
Bull Creek Ranch community. The extreme western, northern, and eastern 
portions of the unit are residential development. Undeveloped stream 
corridors cross the unit from west to east. This unit contains three 
spring sites: Tributary 4 upstream, Tributary 4 downstream, and 
Spicewood Park Dam, which are occupied by the Jollyville Plateau 
salamander. The springs are located on Tributary 4 and an unnamed 
tributary to Bull Creek. The unit contains the primary constituent 
elements essential for the conservation of the species.

[[Page 50819]]

    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed, potential for vandalism, and depletion of groundwater (see 
Special Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the springs, representing the extent of the subterranean 
critical habitat. We joined the edges of the resulting circles.

Georgetown Salamander

Unit 1: Cobb Unit
    Unit 1 consists of 83 ac (34 ha) of private land located in 
northwestern Williamson County, Texas. The unit is undeveloped land. 
This unit contains two springs, Cobb Springs and Cobb Well, both known 
to be occupied by the Georgetown salamander. Cobb Springs is located on 
Cobb Springs Branch, and Cobb Well is located on a tributary to the 
stream. The unit contains the primary constituent elements essential 
for the conservation of the species. Cobb Springs is a surface 
location, and Cobb Well is a subterranean location for the species.
    The unit requires special management because of the potential for 
groundwater pollution from future development in the watershed and 
depletion of groundwater (see Special Management Considerations or 
Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat for Cobb 
Springs. The unit was further delineated by drawing a circle with a 
radius of 984 ft (300 m) around the spring and well, representing the 
extent of the subterranean critical habitat. We joined the edges of the 
resulting circles.
Unit 2: Cowen Creek Spring Unit
    Unit 2 consists of 68 ac (28 ha) of private land located in west-
central Williamson County, Texas. The northern portion of the unit is 
residential development; the remainder is undeveloped. This unit 
contains Cowan Creek Spring, which is occupied by the Georgetown 
salamander. The spring is located on Cowan Creek. The unit contains the 
primary constituent elements essential for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 3: Bat Well Unit
    Unit 3 consists of 68 ac (28 ha) of private land located in west-
central Williamson County, Texas. The western, northern, and southern 
portion of the unit contains residential development. This unit 
contains Bat Well, located in a cave and known to be occupied by the 
Georgetown salamander. The cave is located in the Cowan Creek 
watershed. The unit contains the primary constituent elements essential 
for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the cave. The unit was further 
delineated by drawing a circle with a radius of 984 ft (300 m) around 
the cave, representing the extent of the subterranean critical habitat.
Unit 4: Walnut Spring Unit
    Unit 4 consists of 68 ac (28 ha) of private and Williamson County 
land located in west-central Williamson County, Texas. The western, 
eastern, and northeastern portions of the unit contain low-density 
residential development; the southern and north-central portions are 
undeveloped. The extreme southeastern corner of the unit is part of 
Williamson County Conservation Foundation's Twin Springs Preserve. This 
unit contains Walnut Spring, which is occupied by the Georgetown 
salamander. The spring is located on Walnut Spring Hollow. The unit 
contains the primary constituent elements for the conservation of the 
species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 5: Twin Springs Unit
    Unit 5 consists of 68 ac (28 ha) of private and Williamson County 
land located in west-central Williamson County, Texas. The northern 
portion of the unit contains low-density residential development; the 
remainder of the unit is undeveloped. The majority of the unit is part 
of Williamson County Conservation Foundation's Twin Springs Preserve. 
The preserve is managed by Williamson Conservation Foundation as a 
mitigation property for the take of golden-cheeked warbler and Bone 
Cave under the Williamson County Regional Habitat Conservation Plan. 
The preserve habitat will be undeveloped in perpetuity. Salamander 
populations are monitored, and there is some control of public access. 
This unit contains Twin Springs, which is occupied by the Georgetown 
salamander. The spring is located on Taylor Ray Hollow, a tributary of 
Lake Georgetown. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 6: Hogg Hollow Spring Unit
    Unit 6 consists of 68 ac (28 ha) of private and Federal undeveloped 
land located in west-central Williamson County, Texas. Part of this 
unit is on the U.S. Army Corps of Engineers Lake Georgetown's property. 
There are currently no plans to develop the property. There is some 
control of public access. This unit contains Hogg Hollow Spring, which 
is occupied by the Georgetown salamander. The spring is located on Hogg 
Hollow, a tributary to Lake Georgetown. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and

[[Page 50820]]

depletion of groundwater (see Special Management Considerations or 
Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 7: Cedar Hollow Spring Unit
    Unit 7 consists of 68 ac (28 ha) of private land in west-central 
Williamson County, Texas. A secondary road crossed the extreme southern 
portion of the unit, and there are residences in the northwestern, 
southwestern, and west central portions of the unit. This unit contains 
Cedar Hollow Spring, which is occupied by the Georgetown salamander. 
The spring is located on Cedar Hollow, a tributary to Lake Georgetown. 
The unit contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 8: Lake Georgetown Unit
    Unit 8 consists of 132 ac (53 ha) of Federal and private land in 
west-central Williamson County, Texas. Part of the unit is U.S. Army 
Corps of Engineers Lake Georgetown property. There are currently no 
plans to develop the property. There is some control of public access. 
Unpaved roads are found in the western portion of the unit, and a trail 
begins in the central part of the unit and leaves the northeast corner. 
A secondary road crosses the extreme southern portion of the unit, and 
there are residences in the northwestern, southwestern, and west 
central portions of the unit. A large quarry is located a short 
distance southeast of the unit. This unit two springs, Knight (Crockett 
Gardens) Spring and Cedar Breaks Hiking Trail Spring, which are 
occupied by the Georgetown salamander. The springs are located on an 
unnamed tributary to Lake Georgetown. A portion of the northern part of 
the unit extends under Lake Georgetown. The unit contains the primary 
constituent elements essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed present operations and future expansion of the quarry, and 
depletion of groundwater (see Special Management Considerations or 
Protection section).
    The proposed designation includes the spring outlets and outflows 
up to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around each of the two springs, representing the extent of the 
subterranean critical habitat. We joined the edges of the resulting 
circles.
Unit 9: Water Tank Cave Unit
    Unit 9 consists of 68 ac (28 ha) of private land in west-central 
Williamson County, Texas. A golf course crosses the unit from northwest 
to southeast, and there are several roads in the eastern part of the 
unit. A secondary road crosses the extreme southern portion of the 
unit, and there are residences in the northwestern, southwestern, and 
west central portions of the unit. This unit contains Water Tank Cave, 
a subterranean location, which is occupied by the Georgetown 
salamander. The unit contains the primary constituent elements 
essential for the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the subterranean cave. The unit 
was further delineated by drawing a circle with a radius of 984 ft (300 
m) around the cave, representing the extent of the subterranean 
critical habitat.
Unit 10: Avant Spring Unit
    Unit 10 consists of 68 ac (28 ha) of private land in west-central 
Williamson County, Texas. The northern part of a large quarry is along 
the southwestern edge of the unit. The rest of the unit is undeveloped. 
This unit contains Avant's (Capitol Aggregates) Spring, which is 
occupied by the Georgetown salamander. The spring is close to the 
streambed of the Middle Fork of the San Gabriel River. The unit 
contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlet and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 11: Buford Hollow Spring Unit
    Unit 11 consists of 68 ac (28 ha) of Federal and private land in 
west-central Williamson County, Texas. The unit is located just below 
the spillway for Lake Georgetown. The U.S. Army Corps of Engineers owns 
most of this unit as part of Lake Georgetown. The D.B. Wood Road, a 
major thoroughfare, crosses the eastern part of the unit. The rest of 
the unit is undeveloped. This unit contains Buford Hollow Springs, 
which is occupied by the Georgetown salamander. The spring is located 
on Buford Hollow, a tributary to the North Fork San Gabriel River. The 
unit contains the primary constituent elements essential for the 
conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 12: Swinbank Spring Unit
    Unit 12 consists of 68 ac (28 ha) of City and private land in west-
central Williamson County, Texas. The unit is located near River Road 
south of Melanie Lane. The northern part of the unit is primarily in 
residential development, while the southern part of this unit is 
primarily undeveloped. This unit contains Swinbank Spring, which is 
occupied by the Georgetown salamander. The spring is located just off 
the main channel of North Fork San Gabriel River. The unit contains the 
primary constituent elements essential for the conservation of the 
species. The population of Georgetown salamanders in the spring is 
being monitored monthly as part of the Williamson

[[Page 50821]]

County Regional HCP's efforts to conserve the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section). Although the Georgetown 
salamander has been given special consideration under the Williamson 
County Regional HCP, take is not covered for this species (Williamson 
County Conservation Foundation 2008, pp. 4-19). Actions authorized 
under the HCP for the covered species may impact the Georgetown 
salamander through habitat degradation (Williamson County Conservation 
Foundation 2008, pp. 4-19). This includes increased impervious cover 
and the associated decline in water quality.
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 13: Shadow Canyon Unit
    Unit 13 consists of 68 ac (28 ha) of City and private land in west-
central Williamson County, Texas. The unit is located just south of 
State Highway 29. This unit contains Shadow Canyon Spring, which is 
occupied by the Georgetown salamander. The spring is located on an 
unnamed tributary of South Fork San Gabriel River. The unit contains 
the essential primary constituent elements for the conservation of the 
species. The unit is authorized for development under the Shadow Canyon 
HCP. Impacts to the endangered golden-cheeked warbler (Dendroica 
chrysoparia) and Bone Cave harvestman (Texella reyesi) are permitted; 
however, impacts to Georgetown salamander are not covered under the 
HCP.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 14: San Gabriel Springs Unit
    Unit 14 consists of 68 ac (28 ha) of City of Georgetown land in 
west-central Williamson County, Texas. The unit is located between 
North College Street and East Morrow Street, just north of the San 
Gabriel River in San Gabriel Park. The northern part of the unit 
contains some park buildings, parking lots, and other impervious 
surfaces, but only the subterranean aquifer that extends below these 
structures is included in the critical habitat unit. The southern part 
of the unit is primarily undeveloped. This unit contains San Gabriel 
Springs, which is occupied by the Georgetown salamander. Even though 
the species has not been collected on the surface there since 1991 
(Chippindale et al. 2000, p. 40; Pierce 2011b, pers. comm.), it may 
occur on the subsurface. Therefore, we consider this unit to be 
currently occupied. The spring is located just off the main channel of 
the San Gabriel River, downstream of the confluence of the North San 
Gabriel and South San Gabriel rivers. A city well is located 
approximately 82 ft (25 m) from one of the spring outlets, and causes 
the spring to go dry when it is active during the summer (TPWD 2011a, 
p. 9). The unit contains the primary constituent elements essential for 
the conservation of the species.
    The unit requires special management because of the potential for 
groundwater pollution from current and future development in the 
watershed and depletion of groundwater from pumping (see Special 
Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.

Salado Salamander

Unit 1: Hog Hollow Spring Unit
    Unit 1 consists of 68 ac (28 ha) of private land located in 
southwestern Bell County, Texas. The unit is primarily undeveloped 
ranch land. This unit contains Hog Hollow Spring, which is occupied by 
the Salado salamander. The unit is located on a tributary to Rumsey 
Creek in the Salado Creek drainage and contains the primary constituent 
elements essential for the conservation of the species. The owners of 
the spring are interested in conserving the species, but there are 
currently no long-term commitments to conservation in place.
    The unit requires special management because of the potential for 
groundwater pollution from future development in the watershed, 
destruction of habitat by feral hogs, future depletion of groundwater, 
and disturbance of habitat by livestock (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 2: Solana Spring 1 Unit
    Unit 2 consists of 68 ac (28 ha) of private land located in 
southwestern Bell County, Texas. The unit is primarily undeveloped 
ranch land. This unit contains Solana Spring 1, which is 
occupied by the Salado salamander. The unit is located on a tributary 
to Rumsey Creek in the Salado Creek drainage and contains the primary 
constituent elements essential for the conservation of the species. The 
owners of the spring are interested in conserving the species, but 
there are currently no long-term commitments to conservation in place.
    The unit requires special management because of the potential for 
groundwater pollution from future development in the watershed, 
destruction of habitat by feral hogs, future depletion of groundwater, 
and disturbance of habitat by livestock (see Special Management 
Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 3: Cistern Spring Unit
    Unit 3 consists of 68 ac (28 ha) of private land located in 
southwestern Bell County, Texas, on the same private ranch as Units 1 
and 2 for the Salado salamander. The unit is primarily undeveloped 
ranch land. This unit contains Cistern Spring, which is occupied by the 
Salado salamander. The unit is located on a tributary to Rumsey Creek 
in the Salado Creek drainage and contains the primary constituent 
elements essential for the conservation of the species. The owners of 
the spring are interested in conserving the species, but there are 
currently no long-term commitments to conservation in place.
    The unit requires special management because of the potential for 
groundwater

[[Page 50822]]

pollution from future development in the watershed, destruction of 
habitat by feral hogs, future depletion of groundwater, and disturbance 
of habitat by livestock (see Special Management Considerations or 
Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around the spring, representing the extent of the subterranean 
critical habitat.
Unit 4: IH-35 Unit
    Unit 4 consists of 168 ac (68 ha) of private, State, and City of 
Salado land located in southwestern Bell County, Texas, in the southern 
part of the Village of Salado. The unit extends along Salado Creek on 
both sides of Interstate Highway 35 (IH 35). The IH 35 right of way 
crosses Salado Creek and is owned by the Texas Department of 
Transportation. The unit is a mixture of residential and commercial 
properties on its eastern portion, with some undeveloped ranch land in 
the western part west of IH 35. This unit contains four springs, all 
located on private property: Robertson Spring, Big Boiling Spring, Lil' 
Bubbly Spring, and Lazy Days Fish Farm, all known to be occupied by the 
Salado salamander.
    There has been some recent modification to the spring habitat 
within this unit. In the fall of 2011, the outflow channels and edges 
of Big Boiling and Lil' Bubbly Spring were reconstructed with large 
limestone blocks and mortar. In addition, in response to other activity 
in the area, the U.S. Army Corps of Engineers issued a cease and desist 
order to the Salado Chamber of Commerce in October 2011, for 
unauthorized discharge of dredged or fill material that occurred in 
this area (Brooks 2011, U.S. Corps of Engineers, pers. comm.). This 
order was issued in relation to the need for a section 404 permit under 
the Clean Water Act. A citation from a TPWD game warden was also issued 
in October 2011, due to the need for a sand and gravel permit from the 
TPWD for work being conducted within TPWD jurisdiction (Heger 2012a, 
pers. comm.). The citation was issued because the Salado Chamber of 
Commerce had been directed by the game warden to stop work within 
TPWD's jurisdiction, which the Salado Chamber of Commerce did 
temporarily, but work started again in spite of the game warden's 
directive (Heger 2012a, pers. comm.). A sand and gravel permit was 
obtained on March 21, 2012. The spring run modifications were already 
completed by this date, but further modifications in the springs were 
prohibited by the permit. Additional work on the bank upstream of the 
springs was permitted and completed (Heger 2012b, pers. comm.).
    The unit requires special management to protect it from illegal 
dumping within the stream channel, surface runoff from nearby roads and 
other development, the potential for groundwater pollution from future 
development in the watershed, future depletion of groundwater, and 
habitat disturbance from livestock and feral hogs (see Special 
Management Considerations or Protection section).
    The proposed designation includes the spring outlets and outflow up 
to the high water line and 164 ft (50 m) of downstream habitat. The 
unit was further delineated by drawing a circle with a radius of 984 ft 
(300 m) around each of the four springs, representing the extent of the 
subterranean critical habitat. We then joined the edges of the 
resulting circles.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that any action they fund, authorize, or carry out 
is not likely to jeopardize the continued existence of any endangered 
species or threatened species or result in the destruction or adverse 
modification of designated critical habitat of such species. In 
addition, section 7(a)(4) of the Act requires Federal agencies to 
confer with the Service on any agency action which is likely to 
jeopardize the continued existence of any species proposed to be listed 
under the Act or result in the destruction or adverse modification of 
proposed critical habitat.
    Decisions by the 5th and 9th Circuit Courts of Appeals have 
invalidated our regulatory definition of ``destruction or adverse 
modification'' (50 CFR 402.02) (see Gifford Pinchot Task Force v. U.S. 
Fish and Wildlife Service, 378 F. 3d 1059 (9th Cir. 2004) and Sierra 
Club v. U.S. Fish and Wildlife Service et al., 245 F.3d 434, 442 (5th 
Cir. 2001)), and we do not rely on this regulatory definition when 
analyzing whether an action is likely to destroy or adversely modify 
critical habitat. Under the statutory provisions of the Act, we 
determine destruction or adverse modification on the basis of whether, 
with implementation of the proposed Federal action, the affected 
critical habitat would continue to serve its intended conservation role 
for the species.
    If a Federal action may affect a listed species or its critical 
habitat, the responsible Federal agency (action agency) must enter into 
consultation with us. Examples of actions that are subject to the 
section 7 consultation process are actions on State, tribal, local, or 
private lands that require a Federal permit (such as a permit from the 
U.S. Army Corps of Engineers under section 404 of the Clean Water Act 
(33 U.S.C. 1251 et seq.) or a permit from the Service under section 10 
of the Act) or that involve some other Federal action (such as funding 
from the Federal Highway Administration, Federal Aviation 
Administration, or the Federal Emergency Management Agency). Federal 
actions not affecting listed species or critical habitat, and actions 
on State, tribal, local, or private lands that are not federally funded 
or authorized, do not require section 7 consultation.
    As a result of section 7 consultation, we document compliance with 
the requirements of section 7(a)(2) through our issuance of:
    (1) A concurrence letter for Federal actions that may affect, but 
are not likely to adversely affect, listed species or critical habitat; 
or
    (2) A biological opinion for Federal actions that may affect, or 
are likely to adversely affect, listed species or critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to jeopardize the continued existence of a listed species and 
destroy or adversely modify critical habitat, we provide reasonable and 
prudent alternatives to the project, if any are identifiable, that 
would avoid the likelihood of jeopardy and destruction or adverse 
modification of critical habitat. We define ``reasonable and prudent 
alternatives'' (at 50 CFR 402.02) as alternative actions identified 
during consultation that:
    (1) Can be implemented in a manner consistent with the intended 
purpose of the action,
    (2) Can be implemented consistent with the scope of the Federal 
agency's legal authority and jurisdiction,
    (3) Are economically and technologically feasible, and
    (4) Would, in the Director's opinion, avoid the likelihood of 
jeopardizing the continued existence of the listed species and avoid 
the likelihood of destroying or adversely modifying critical habitat.
    Reasonable and prudent alternatives can vary from slight project 
modifications to extensive redesign or relocation of the project. Costs 
associated with implementing a reasonable and prudent alternative are 
similarly variable.
    Regulations at 50 CFR 402.16 require Federal agencies to reinitiate

[[Page 50823]]

consultation on previously reviewed actions in instances where we have 
listed a new species or subsequently designated critical habitat that 
may be affected and the Federal agency has retained discretionary 
involvement or control over the action (or the agency's discretionary 
involvement or control is authorized by law). Consequently, Federal 
agencies sometimes may need to request reinitiation of consultation 
with us on actions for which formal consultation has been completed, if 
those actions with discretionary involvement or control may affect 
subsequently listed species or designated critical habitat.

Application of the ``Adverse Modification'' Standard

    The key factor related to the adverse modification determination is 
whether, with implementation of the proposed Federal action, the 
affected critical habitat would continue to serve its intended 
conservation role for the species. Activities that may destroy or 
adversely modify critical habitat are those that alter the physical or 
biological features to an extent that appreciably reduces the 
conservation value of critical habitat for the four salamander species. 
As discussed above, the role of critical habitat is to support life-
history needs of the species and provide for the conservation of the 
species.
    Section 4(b)(8) of the Act requires us to briefly evaluate and 
describe, in any proposed or final regulation that designates critical 
habitat, activities involving a Federal action that may destroy or 
adversely modify such habitat, or that may be affected by such 
designation.
    Activities that may affect critical habitat, when carried out, 
funded, or authorized by a Federal agency, should result in 
consultation for the four salamander species. These activities include, 
but are not limited to:
    (1) Actions that would physically disturb the spring habitat upon 
which these four Texas salamander species depend. Such activities could 
include, but are not limited to, channelization and other activities 
that result in the physical destruction of habitat or the modification 
of habitat so that it is not suitable for the species.
    (2) Actions that would increase the concentration of silt in the 
surface or subsurface habitat. Such activities could include, but are 
not limited to, increases in impervious cover in the surface watershed, 
improper erosion controls on the surface and subsurface watersheds, 
release of pollutants into the surface water or connected groundwater 
at a point source or by dispersed release (non-point source). These 
activities could alter water conditions to levels that are beyond the 
tolerances of the four Texas salamander species and result in direct or 
cumulative adverse effects to these individuals and their life cycles.
    (3) Actions that would deplete the aquifer to an extent that 
decreases or stops the flow of occupied springs or that reduce the 
quantity of subterranean habitat used by the species. Such activities 
could include, but are not limited to, excessive water withdrawals from 
aquifers and channelization or other modification of recharge features 
that would decrease recharge. These activities could dewater habitat or 
cause reduced water quality to levels that are beyond the tolerances of 
the four Texas salamanders and result in direct or cumulative adverse 
effects to these individuals and their life cycles.

Exemptions

Application of Section 4(a)(3) of the Act

    The Sikes Act Improvement Act of 1997 (Sikes Act) (16 U.S.C. 670a) 
required each military installation that includes land and water 
suitable for the conservation and management of natural resources to 
complete an integrated natural resources management plan (INRMP) by 
November 17, 2001. An INRMP integrates implementation of the military 
mission of the installation with stewardship of the natural resources 
found on the base. Each INRMP includes:
    (1) An assessment of the ecological needs on the installation, 
including the need to provide for the conservation of listed species;
    (2) A statement of goals and priorities;
    (3) A detailed description of management actions to be implemented 
to provide for these ecological needs; and
    (4) A monitoring and adaptive management plan.
    Among other things, each INRMP must, to the extent appropriate and 
applicable, provide for fish and wildlife management; fish and wildlife 
habitat enhancement or modification; wetland protection, enhancement, 
and restoration where necessary to support fish and wildlife; and 
enforcement of applicable natural resource laws.
    The National Defense Authorization Act for Fiscal Year 2004 (Pub. 
L. 108-136) amended the Act to limit areas eligible for designation as 
critical habitat. Specifically, section 4(a)(3)(B)(i) of the Act (16 
U.S.C. 1533(a)(3)(B)(i)) now provides: ``The Secretary shall not 
designate as critical habitat any lands or other geographic areas owned 
or controlled by the Department of Defense, or designated for its use, 
that are subject to an integrated natural resources management plan 
prepared under section 101 of the Sikes Act (16 U.S.C. 670a), if the 
Secretary determines in writing that such plan provides a benefit to 
the species for which critical habitat is proposed for designation.''
    There are no Department of Defense lands within the proposed 
critical habitat designation.

Exclusions

Application of Section 4(b)(2) of the Act

    Section 4(b)(2) of the Act states that the Secretary shall 
designate and make revisions to critical habitat on the basis of the 
best available scientific data after taking into consideration the 
economic impact, national security impact, and any other relevant 
impact of specifying any particular area as critical habitat. The 
Secretary may exclude an area from critical habitat if he determines 
that the benefits of such exclusion outweigh the benefits of specifying 
such area as part of the critical habitat, unless he determines, based 
on the best scientific data available, that the failure to designate 
such area as critical habitat will result in the extinction of the 
species. In making that determination, the statute on its face, as well 
as the legislative history are clear that the Secretary has broad 
discretion regarding which factor(s) to use and how much weight to give 
to any factor.
    In considering whether to exclude a particular area from the 
designation, we identify the benefits of including the area in the 
designation, identify the benefits of excluding the area from the 
designation, and evaluate whether the benefits of exclusion outweigh 
the benefits of inclusion. If the analysis indicates that the benefits 
of exclusion outweigh the benefits of inclusion, the Secretary may 
exercise his discretion to exclude the area only if such exclusion 
would not result in the extinction of the species.
    When identifying the benefits of inclusion for an area, we consider 
the additional regulatory benefits that area would receive from the 
protection from adverse modification or destruction as a result of 
actions with a Federal nexus; the educational benefits of mapping 
essential habitat for recovery of the listed species; and any benefits 
that may result from a designation due to State or Federal laws that 
may apply to critical habitat.
    When identifying the benefits of exclusion, we consider, among 
other

[[Page 50824]]

things, whether exclusion of a specific area is likely to result in 
conservation; the continuation, strengthening, or encouragement of 
partnerships; or implementation of a management plan that provides 
equal to or more conservation than a critical habitat designation would 
provide.
    In the case of the four central Texas salamanders, the benefits of 
critical habitat include public awareness of Austin blind salamander, 
Georgetown salamander, Jollyville Plateau salamander, and Salado 
salamander presence and the importance of habitat protection, and in 
cases where a Federal nexus exists, increased habitat protection for 
Austin blind salamander, Georgetown salamander, Jollyville Plateau 
salamander, and Salado salamander due to the protection from adverse 
modification or destruction of critical habitat.
    When we evaluate the existence of a conservation plan when 
considering the benefits of exclusion, we consider a variety of 
factors, including but not limited to, whether the plan is finalized; 
how it provides for the conservation of the essential physical or 
biological features; whether there is a reasonable expectation that the 
conservation management strategies and actions contained in a 
management plan will be implemented into the future; whether the 
conservation strategies in the plan are likely to be effective; and 
whether the plan contains a monitoring program or adaptive management 
to ensure that the conservation measures are effective and can be 
adapted in the future in response to new information.
    After identifying the benefits of inclusion and the benefits of 
exclusion, we carefully weigh the two sides to evaluate whether the 
benefits of exclusion outweigh those of inclusion. If our analysis 
indicates that the benefits of exclusion outweigh the benefits of 
inclusion, we then determine whether exclusion would result in 
extinction. If exclusion of an area from critical habitat will result 
in extinction, we will not exclude it from the designation.
    Based on the information that will be provided by entities seeking 
exclusion, as well as any additional public comments we receive during 
the open public comment period (see DATES), we will evaluate whether 
certain lands in the proposed critical habitat for Jollyville Plateau 
salamander in the Bull Creek 3 Unit (Unit 19 for the Jollyville Plateau 
salamander) are appropriate for exclusion from the final designation 
under section 4(b)(2) of the Act. If the analysis indicates that the 
benefits of excluding lands from the final designation outweigh the 
benefits of designating those lands as critical habitat, then the 
Secretary may exercise his discretion to exclude the lands from the 
final designation.
    After considering the following areas under section 4(b)(2) of the 
Act, we are proposing to exclude them from the critical habitat 
designation for Jollyville Plateau salamander.

     Table 11--Areas Considered for Exclusion by Critical Habitat Unit for the Jollyville Plateau Salamander
----------------------------------------------------------------------------------------------------------------
                                                                Areas meeting the
                                                             definition of critical      Areas  considered for
               Unit                     Specific area           habitat, in acres       possible  exclusion,  in
                                                                   (hectares)              acres  (hectares)
----------------------------------------------------------------------------------------------------------------
Unit 19: Bull Creek 3 Unit........  Four Points HCP......  254 ac (103 ha)             152 ac (62 ha).
----------------------------------------------------------------------------------------------------------------

    We are considering these areas for exclusion, because we believe 
that:
    (1) Their value for conservation will be preserved for the 
foreseeable future by existing protective actions, or
    (2) They are appropriate for exclusion under the ``other relevant 
factor'' provisions of section 4(b)(2) of the Act.
    However, we specifically solicit comments on the inclusion or 
exclusion of such areas. In the paragraphs below, we provide a detailed 
analysis of our exclusion of these lands under section 4(b)(2) of the 
Act.
Exclusions Based on Economic Impacts
    Under section 4(b)(2) of the Act, we consider the economic impacts 
of specifying any particular area as critical habitat. In order to 
consider economic impacts, we are preparing an analysis of the economic 
impacts of the proposed critical habitat designation and related 
factors.
    Sectors that may be affected by the proposed designation include 
private developers of residential and commercial property; city, 
county, and State governments that construct and maintain roads and 
other infrastructure; and entities that pump water from the aquifers.
    We will announce the availability of the draft economic analysis as 
soon as it is completed, at which time we will seek public review and 
comment. At that time, copies of the draft economic analysis will be 
available for downloading from the Internet at http://www.regulations.gov, or by contacting the Austin Ecological Services 
Field Office directly (see FOR FURTHER INFORMATION CONTACT). During the 
development of a final designation, we will consider economic impacts, 
public comments, and other new information, and areas may be excluded 
from the final critical habitat designation under section 4(b)(2) of 
the Act and our implementing regulations at 50 CFR 424.19.
Exclusions Based on National Security Impacts
    Under section 4(b)(2) of the Act, we consider whether there are 
lands owned or managed by the Department of Defense (DOD) where a 
national security impact might exist. In preparing this proposal, we 
have determined that the lands within the proposed designation of 
critical habitat for Austin blind salamander, Georgetown salamander, 
Jollyville Plateau salamander, and Salado salamander are not owned or 
managed by the Department of Defense, and, therefore, we anticipate no 
impact on national security. Consequently, the Secretary does not 
propose to exercise his discretion to exclude any areas from the final 
designation based on impacts on national security.
Exclusions Based on Other Relevant Impacts
    Under section 4(b)(2) of the Act, we consider any other relevant 
impacts, in addition to economic impacts and impacts on national 
security. We consider a number of factors including whether the 
landowners have developed any HCPs or other management plans for the 
area, or whether there are conservation partnerships that would be 
encouraged by designation of, or exclusion from, critical habitat. In 
addition, we look at any tribal issues, and consider the government-to-
government relationship of the United States with tribal entities. We 
also

[[Page 50825]]

consider any social impacts that might occur because of the 
designation.
Land and Resource Management Plans, Conservation Plans, or Agreements 
Based on Conservation Partnerships
    We consider a current land management or conservation plan (HCPs as 
well as other types) to provide adequate management or protection if it 
meets the following criteria:
    (1) The plan is complete and provides the same or better level of 
protection from adverse modification or destruction than that provided 
through a consultation under section 7 of the Act;
    (2) There is a reasonable expectation that the conservation 
management strategies and actions will be implemented for the 
foreseeable future, based on past practices, written guidance, or 
regulations; and
    (3) The plan provides conservation strategies and measures 
consistent with currently accepted principles of conservation biology.
    We believe that the Four Points HCP fulfills the above criteria, 
and are considering the exclusion of non-Federal lands covered by this 
plan that provide for the conservation of Jollyville Plateau 
salamander. We are requesting comments on the benefit to Jollyville 
Plateau salamander from this HCP.

Four Points Habitat Conservation Plan

    The Permittee (TPG Four Points Land, L.P.) is authorized to 
``take'' (kill, harm, or harass) the golden-cheeked warbler, black-
capped vireo, Tooth Cave ground beetle, Bone Cave harvestman, Bee Creek 
Cave harvestman, Tooth Cave pseudoscorpion (Tartarocreagris texana), 
Tooth Cave spider (Tayshaneta myopica), Kretschmarr Cave mold beetle 
(Texamaurops reddelli), and the Coffin Cave mold beetle (Batrisodes 
texanus) at a known location (the 333-ac (135-ha) Four Points Property, 
located approximately 11 mi (18 km) northwest of Austin near the 
intersection of RM 2222 and RM 620, Travis County, Texas), of habitat 
for these species, incidental to activities necessary for the 
construction of mixed use real estate development projects and 
attendant utilities as described in the original Permittee's (P-WB 
Joint Venture) application and habitat conservation plan. The HCP also 
covers the Jollyville Plateau salamander as if it were a listed 
species, meaning that impacts to this salamander species from 
construction activites described in the permit are permitted.
    The HCP requires avoidance of direct impacts to warblers by not 
conducting clearing or construction in occupied golden-cheeked warbler 
habitat and by initiating clearing and construction only during times 
of year when birds are not present. Approximately 52 ac (21 ha) that 
contains six caves (Owl Eyes, Japygid, Eluvial, Fernpit, M.W.A., and 
Jollyville) known to be inhabited by Tooth Cave ground beetle and the 
Bone Cave harvestman have been permanently preserved.
    Protection of this area is also expected to contribute to the 
maintenance of water quality, and, therefore, the quality of salamander 
habitat at resurgence springs (Spring No. 12, Spring No. 22, and Spring 
No. 24) down-gradient of the preserve area. In addition, runoff from 
multi-family residential areas and the hotel will be routed to avoid 
drainages which contain springs known to support Jollyville Plateau 
salamanders.
    In addition to the karst preserve, another approximately 135 ac (54 
ha) of the property was permanently set aside and maintained as a 
golden-cheeked warbler preserve.
    All preserve areas will be permanently fenced and posted to 
preclude public access, and red imported fire ants (Solenopsis invicta) 
will be controlled in the karst preserves. Fire ants are a pervasive, 
nonnative ant species originally introduced to the United States from 
South America over 50 years ago and are an aggressive predator and 
competitor that has spread across the southern United States. They 
often replace native species, and evidence shows that overall arthropod 
diversity, as well as species richness and abundance, decreases in 
infested areas. Fire ants are spread by activities that accompany 
urbanization and that result in soil disturbance and disruption to 
native ant communities. As such, fire ants will be controlled by 
limiting these types of activities. No pesticides or herbicides will be 
used within preserve areas, and any pesticides or herbicides used 
within developed areas will be used according to the EPA label 
instructions.

Peer Review

    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), we will seek the expert 
opinions of at least three appropriate and independent specialists 
regarding this proposed rule. The purpose of peer review is to ensure 
that our listing determination and critical habitat designation are 
based on scientifically sound data, assumptions, and analyses. We have 
invited these peer reviewers to comment during this public comment 
period on our specific assumptions and conclusions in this proposed 
listing and designation of critical habitat.
    We will consider all comments and information we receive during 
this comment period on this proposed rule during our preparation of a 
final determination. Accordingly, the final decision may differ from 
this proposal.

Public Hearings

    Section 4(b)(5) of the Act provides for one or more public hearings 
on this proposal, if requested. Requests must be received within 45 
days after the date of publication of this proposed rule in the Federal 
Register. Such requests must be sent to the address shown in the FOR 
FURTHER INFORMATION CONTACT section. We will schedule public hearings 
on this proposal, if any are requested, and announce the dates, times, 
and places of those hearings, as well as how to obtain reasonable 
accommodations, in the Federal Register and local newspapers at least 
15 days before the hearing.

Required Determinations

Regulatory Planning and Review--Executive Order 12866

    Executive Order 12866 provides that the Office of Information and 
Regulatory Affairs (OIRA) will review all significant rules. The Office 
of Information and Regulatory Affairs has determined that this rule is 
not significant.
    Executive Order 13563 reaffirms the principles of E.O. 12866 while 
calling for inprovements in the nation's regulatory system to promote 
predictability, to reduce uncertainty, and to use the best, most 
innovative, and least burdensome tools for achieving regulatory ends. 
The executive order directs agencies to consider regulatory approaches 
that reduce burdens and maintain flexibility and freedom of choice for 
the public where these approaches are relevant, feasible, and 
consistent with regulatory objectives. E.O. 13563 emphasizes further 
that regulations must be based on the best available science and that 
the rulemaking process must allow for public participation and an open 
exchange of ideas. We have developed this rule in a manner consistent 
with these requirements.

Regulatory Flexibility Act (5 U.S.C. 601 et seq.)

    Under the Regulatory Flexibility Act (RFA; 5 U.S.C. 601 et seq.) as 
amended by the Small Business Regulatory Enforcement Fairness Act of 
1996 (SBREFA; 5 U.S.C. 801 et seq.), whenever an agency is required to 
publish a notice of rulemaking for any proposed or final rule, it must 
prepare

[[Page 50826]]

and make available for public comment a regulatory flexibility analysis 
that describes the effects of the rule on small entities (small 
businesses, small organizations, and small government jurisdictions). 
However, no regulatory flexibility analysis is required if the head of 
the agency certifies the rule will not have a significant economic 
impact on a substantial number of small entities. The SBREFA amended 
the RFA to require Federal agencies to provide a certification 
statement of the factual basis for certifying that the rule will not 
have a significant economic impact on a substantial number of small 
entities.
    According to the Small Business Administration, small entities 
include small organizations such as independent nonprofit 
organizations; small governmental jurisdictions, including school 
boards and city and town governments that serve fewer than 50,000 
residents; and small businesses (13 CFR 121.201). Small businesses 
include such businesses as manufacturing and mining concerns with fewer 
than 500 employees, wholesale trade entities with fewer than 100 
employees, retail and service businesses with less than $5 million in 
annual sales, general and heavy construction businesses with less than 
$27.5 million in annual business, special trade contractors doing less 
than $11.5 million in annual business, and forestry and logging 
operations with fewer than 500 employees and annual business less than 
$7 million. To determine whether small entities may be affected, we 
will consider the types of activities that might trigger regulatory 
impacts under this designation as well as types of project 
modifications that may result. In general, the term ``significant 
economic impact'' is meant to apply to a typical small business firm's 
business operations.
    Importantly, the incremental impacts of a rule must be both 
significant and substantial to prevent certification of the rule under 
the RFA and to require the preparation of an initial regulatory 
flexibility analysis. If a substantial number of small entities are 
affected by the proposed critical habitat designation, but the per-
entity economic impact is not significant, the Service may certify. 
Likewise, if the per-entity economic impact is likely to be 
significant, but the number of affected entities is not substantial, 
the Service may also certify.
    Under the RFA, as amended, and following recent court decisions, 
Federal agencies are only required to evaluate the potential 
incremental impacts of rulemaking on those entities directly regulated 
by the rulemaking itself, and not the potential impacts to indirectly 
affected entities. The regulatory mechanism through which critical 
habitat protections are realized is section 7 of the Act, which 
requires Federal agencies, in consultation with the Service, to ensure 
that any action authorized, funded, or carried by the Agency is not 
likely to adversely modify critical habitat. Therefore, only Federal 
action agencies are directly subject to the specific regulatory 
requirement (avoiding destruction and adverse modification) imposed by 
critical habitat designation. Under these circumstances, it is our 
position that only Federal action agencies will be directly regulated 
by this designation. Therefore, because Federal agencies are not small 
entities, the Service may certify that the proposed critical habitat 
rule will not have a significant economic impact on a substantial 
number of small entities.
    We acknowledge, however, that in some cases, third-party proponents 
of the action subject to permitting or funding may participate in a 
section 7 consultation, and thus may be indirectly affected. We believe 
it is good policy to assess these impacts if we have sufficient data 
before us to complete the necessary analysis, whether or not this 
analysis is strictly required by the RFA. While this regulation does 
not directly regulate these entities, in our draft economic analysis we 
will conduct a brief evaluation of the potential number of third 
parties participating in consultations on an annual basis in order to 
ensure a more complete examination of the incremental effects of this 
proposed rule in the context of the RFA.
    In conclusion, we believe that, based on our interpretation of 
directly regulated entities under the RFA and relevant case law, this 
designation of critical habitat will only directly regulate Federal 
agencies which are not by definition small business entities. And as 
such, certify that, if promulgated, this designation of critical 
habitat would not have a significant economic impact on a substantial 
number of small business entities. Therefore, an initial regulatory 
flexibility analysis is not required. However, though not necessarily 
required by the RFA, in our draft economic analysis for this proposal 
we will consider and evaluate the potential effects to third parties 
that may be involved with consultations with Federal action agencies 
related to this action.

Energy Supply, Distribution, or Use--Executive Order 13211

    Executive Order 13211 (Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use) requires 
agencies to prepare Statements of Energy Effects when undertaking 
certain actions.
    We do not expect the designation of this proposed critical habitat 
to significantly affect energy supplies, distribution, or use, because 
the majority of the lands we are proposing as critical habitat are 
privately owned, and do not have energy production or distribution. 
Therefore, this action is not a significant energy action, and no 
Statement of Energy Effects is required. However, we will further 
evaluate this issue as we conduct our economic analysis, and review and 
revise this assessment as warranted.

Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.), we make the following findings:
    (1) This rule would not produce a Federal mandate. In general, a 
Federal mandate is a provision in legislation, statute, or regulation 
that would impose an enforceable duty upon State, local, or tribal 
governments, or the private sector, and includes both ``Federal 
intergovernmental mandates'' and ``Federal private sector mandates.'' 
These terms are defined in 2 U.S.C. 658(5)-(7). ``Federal 
intergovernmental mandate'' includes a regulation that ``would impose 
an enforceable duty upon State, local, or tribal governments'' with two 
exceptions. It excludes ``a condition of Federal assistance.'' It also 
excludes ``a duty arising from participation in a voluntary Federal 
program,'' unless the regulation ``relates to a then-existing Federal 
program under which $500,000,000 or more is provided annually to State, 
local, and tribal governments under entitlement authority,'' if the 
provision would ``increase the stringency of conditions of assistance'' 
or ``place caps upon, or otherwise decrease, the Federal Government's 
responsibility to provide funding,'' and the State, local, or tribal 
governments ``lack authority'' to adjust accordingly. At the time of 
enactment, these entitlement programs were: Medicaid; Aid to Families 
with Dependent Children work programs; Child Nutrition; Food Stamps; 
Social Services Block Grants; Vocational Rehabilitation State Grants; 
Foster Care, Adoption Assistance, and Independent Living; Family 
Support Welfare Services; and Child Support

[[Page 50827]]

Enforcement. ``Federal private sector mandate'' includes a regulation 
that ``would impose an enforceable duty upon the private sector, except 
(i) a condition of Federal assistance or (ii) a duty arising from 
participation in a voluntary Federal program.''
    The designation of critical habitat does not impose a legally 
binding duty on non-Federal Government entities or private parties. 
Under the Act, the only regulatory effect is that Federal agencies must 
ensure that their actions do not destroy or adversely modify critical 
habitat under section 7. While non-Federal entities that receive 
Federal funding, assistance, or permits, or that otherwise require 
approval or authorization from a Federal agency for an action, may be 
indirectly impacted by the designation of critical habitat, the legally 
binding duty to avoid destruction or adverse modification of critical 
habitat rests squarely on the Federal agency. Furthermore, to the 
extent that non-Federal entities are indirectly impacted because they 
receive Federal assistance or participate in a voluntary Federal aid 
program, the Unfunded Mandates Reform Act would not apply, nor would 
critical habitat shift the costs of the large entitlement programs 
listed above onto State governments.
    (2) We do not believe that this rule would significantly or 
uniquely affect small governments because the proposed areas that cover 
small government jurisdictions are small, and there is little potential 
that the proposal would impose significant additional costs above those 
associated with the proposed listing of the species. Therefore, a Small 
Government Agency Plan is not required. However, we will further 
evaluate this issue as we conduct our economic analysis, and review and 
revise this assessment if appropriate.

Takings--Executive Order 12630

    In accordance with Executive Order 12630 (Government Actions and 
Interference with Constitutionally Protected Private Property Rights), 
we will analyze the potential takings implications of designating 
critical habitat for the Austin blind salamander, Georgetown 
salamander, Jollyville Plateau salamander, and Salado salamander in a 
takings implications assessment. Following publication of this proposed 
rule, a draft economic analysis will be completed for the proposed 
designation. The draft economic analysis will provide the foundation 
for us to use in preparing a takings implications assessment.

Federalism--Executive Order 13132

    In accordance with Executive Order 13132 (Federalism), this 
proposed rule does not have significant Federalism effects. A 
Federalism assessment is not required. In keeping with Department of 
the Interior and Department of Commerce policy, we requested 
information from, and coordinated development of, this proposed 
critical habitat designation with appropriate State resource agencies 
in Texas. The designation of critical habitat in areas currently 
occupied by the Austin blind salamander, Georgetown salamander, 
Jollyville Plateau salamander, and Salado salamander may impose nominal 
additional regulatory restrictions to those currently in place and, 
therefore, may have little incremental impact on State and local 
governments and their activities. The designation may have some benefit 
to these governments because the areas that contain the physical or 
biological features essential to the conservation of the species are 
more clearly defined, and the elements of the features of the habitat 
necessary to the conservation of the species are specifically 
identified. This information does not alter where and what federally 
sponsored activities may occur. However, it may assist local 
governments in long-range planning (rather than having them wait for 
case-by-case section 7 consultations to occur).
    Where State and local governments require approval or authorization 
from a Federal agency for actions that may affect critical habitat, 
consultation under section 7(a)(2) would be required. While non-Federal 
entities that receive Federal funding, assistance, or permits, or that 
otherwise require approval or authorization from a Federal agency for 
an action may be indirectly impacted by the designation of critical 
habitat, the legally binding duty to avoid destruction or adverse 
modification of critical habitat rests squarely on the Federal agency.

Civil Justice Reform--Executive Order 12988

    In accordance with Executive Order 12988 (Civil Justice Reform), 
the Office of the Solicitor has determined that the rule does not 
unduly burden the judicial system and that it meets the requirements of 
sections 3(a) and 3(b)(2) of the Order. We have proposed designating 
critical habitat in accordance with the provisions of the Act. This 
proposed rule uses standard property descriptions and identifies the 
elements of physical or biological features essential to the 
conservation of the Austin blind salamander, Georgetown salamander, 
Jollyville Plateau salamander, and Salado salamander within the 
designated areas to assist the public in understanding the habitat 
needs of the species.

Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)

    This rule does not contain any new collections of information that 
require approval by the Office of Management and Budget under the 
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). This rule 
will not impose recordkeeping or reporting requirements on State or 
local governments, individuals, businesses, or organizations. An agency 
may not conduct or sponsor, and a person is not required to respond to, 
a collection of information unless it displays a currently valid OMB 
control number.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    It is our position that, outside the jurisdiction of the U.S. Court 
of Appeals for the Tenth Circuit, we do not need to prepare 
environmental analyses pursuant to the National Environmental Policy 
Act (NEPA; 42 U.S.C. 4321 et seq.) in connection with designating 
critical habitat under the Act. We published a notice outlining our 
reasons for this determination in the Federal Register on October 25, 
1983 (48 FR 49244). This position was upheld by the U.S. Court of 
Appeals for the Ninth Circuit (Douglas County v. Babbitt, 48 F.3d 1495 
(9th Cir. 1995), cert. denied 516 U.S. 1042 (1996)). The proposed 
designation of critical habitat for the four Texas salamanders is 
entirely within the 5th Circuit jurisdiction; therefore, we do not 
intend to prepare an environmental analysis in connection with this 
proposed critical habitat designation.

Clarity of the Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must:
    (1) Be logically organized;
    (2) Use the active voice to address readers directly;
    (3) Use clear language rather than jargon;
    (4) Be divided into short sections and sentences; and
    (5) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES

[[Page 50828]]

section. To better help us revise the rule, your comments should be as 
specific as possible. For example, you should tell us the numbers of 
the sections or paragraphs that are unclearly written, which sections 
or sentences are too long, the sections where you feel lists or tables 
would be useful, etc.

Government-to-Government Relationship With Tribes

    In accordance with the President's memorandum of April 29, 1994 
(Government-to-Government Relations with Native American Tribal 
Governments; 59 FR 22951), Executive Order 13175 (Consultation and 
Coordination With Indian Tribal Governments), and the Department of the 
Interior's manual at 512 DM 2, we readily acknowledge our 
responsibility to communicate meaningfully with recognized Federal 
Tribes on a government-to-government basis. In accordance with 
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights, 
Federal-Tribal Trust Responsibilities, and the Endangered Species Act), 
we readily acknowledge our responsibilities to work directly with 
tribes in developing programs for healthy ecosystems, to acknowledge 
that tribal lands are not subject to the same controls as Federal 
public lands, to remain sensitive to Indian culture, and to make 
information available to tribes.
    We determined that there are no Tribal lands that are occupied by 
the four central Texas salamanders. Therefore, we are not proposing to 
designate critical habitat for the salamander species on Tribal lands.

References Cited

    A complete list of references cited in this rulemaking is available 
on the Internet at http://www.regulations.gov and upon request from the 
Austin Ecological Services Field Office (see FOR FURTHER INFORMATION 
CONTACT).

Authors

    The primary authors of this package are the staff members of the 
Austin Ecological Services Field Office, Arlington Ecological Services 
Field Office, and the Texas Fish and Wildlife Conservation Office.

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Proposed Regulation Promulgation

    Accordingly, we propose to amend part 17, subchapter B of chapter 
I, title 50 of the Code of Federal Regulations, as set forth below:

PART 17--[AMENDED]

    1. The authority citation for part 17 continues to read as follows:

    Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

    2. Amend Sec.  17.11(h) by adding entries for ``Salamander, Austin 
blind'', ``Salamander, Georgetown'', ``Salamander, Jollyville 
Plateau'', and ``Salamander, Salado'' in alphabetical order under 
AMPHIBIANS to the List of Endangered and Threatened Wildlife to read as 
follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                     When       Critical       Special
                                                           Historic  range       endangered or        Status        listed       habitat        rules
           Common name                Scientific name                              threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
            Amphibians
 
                                                                      * * * * * * *
Salamander, Austin blind.........  Eurycea               U.S.A. (TX)........  Entire.............            E   ...........     17.95(d)            NA
                                    waterlooensis.
 
                                                                      * * * * * * *
Salamander, Georgetown...........  Eurycea naufragia...  U.S.A. (TX)........  Entire.............            E   ...........     17.95(d)            NA
Salamander, Jollyville Plateau...  Eurycea tonkawae....  U.S.A. (TX)........  Entire.............            E   ...........     17.95(d)            NA
 
                                                                      * * * * * * *
Salamander, Salado...............  Eurycea               U.S.A. (TX)........  Entire.............            E   ...........     17.95(d)            NA
                                    chisholmensis.
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. Amend Sec.  17.95(d) by adding entries for ``Austin Blind 
Salamander (Eurycea waterlooensis),'' ``Georgetown Salamander (Eurycea 
naufragia)'', ``Jollyville Plateau Salamander (Eurycea tonkawae)'', and 
``Salado Salamander (Eurycea chisholmensis)'', in the same alphabetical 
order in which the species appear in the table at Sec.  17.11(h), to 
read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (d) Amphibians.
* * * * *
Austin Blind Salamander (Eurycea waterlooensis)
    (1) The critical habitat unit is depicted for Travis County, Texas, 
on the map below.
    (2) Within this area, the primary constituent elements of the 
physical or biological features essential to the conservation of Austin 
blind salamander consist of four components:
    (i) Water from the Barton Springs Segment of the Edwards Aquifer. 
The groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander are below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Austin blind salamander prey base). Hydrologic

[[Page 50829]]

regimes similar to the historical pattern of the specific sites are 
present, with at least temporal surface flow for spring sites and 
continuous flow for subterranean sites. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 67.8 
and 72.3 [deg]F (19.9 and 22.4 [deg]C), dissolved oxygen concentrations 
between 5 and 7 milligrams per liter, and specific water conductance 
between 605 and 740 microsiemens per centimeter.
    (ii) Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat must be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
should have minimal sedimentation.
    (iii) Aquatic invertebrates for food. The spring and cave 
environments must be capable of supporting a diverse aquatic 
invertebrate community that includes crustaceans and insects.
    (iv) Subterranean aquifer. During periods of drought or dewatering 
on the surface in and around spring sites, access to the subsurface 
water table must be provided for shelter and protection.
    (3) Surface critical habitat includes the spring outlets and 
outflow up to the high water line and 164 ft (50 m) of downstream 
habitat, but does not include manmade structures (such as buildings, 
aqueducts, runways, roads, and other paved areas) and the land on which 
they are located existing within the legal boundaries on the effective 
date of this rule; however, the subterranean aquifer may extend below 
such structures. The subterranean critical habitat includes underground 
features in a circle with a radius of 984 ft (300 m) around the 
springs.
    (4) Critical habitat map units. Data layers defining map units were 
created using a geographic information system (GIS), which included 
species locations, roads, property boundaries, 2011 aerial photography, 
and USGS 7.5' quadrangles. Points were placed on the GIS. We delineated 
critical habitat unit boundaries by starting with the cave or spring 
point locations that are occupied by the salamanders. From these cave 
or springs points, we delineated a 984-ft (300-m) buffer to create the 
polygons that capture the extent to which we believe the salamander 
populations exist through underground conduits. The polygons were then 
simplified to reduce the number of vertices, but still retain the 
overall shape and extent. Subsequently, polygons that were within 98 ft 
(30 m) of each other were merged together. Each new merged polygon was 
then revised to remove extraneous divits or protrusions that resulted 
from the merge process. The maps in this entry, as modified by any 
accompanying regulatory text, establish the boundaries of the critical 
habitat designation. The coordinates or plot points or both on which 
each map is based are available to the public at the field office 
Internet site (http://www.fws.gov/southwest/es/AustinTexas/), http://www.regulations.gov at Docket No. FWS-R2-ES-2012-0035 and at the 
Service's Austin Ecological Services Field Office. You may obtain field 
office location information by contacting one of the Service regional 
offices, the addresses of which are listed at 50 CFR 2.2.
    (5) Unit 1: Barton Springs Unit, Travis County, Texas. Map of Unit 
1 follows:
BILLING CODE 4310-55-P

[[Page 50830]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.000

* * * * *
Georgetown Salamander (Eurycea naufragia)
    (1) Critical habitat units are depicted for Williamson County, 
Texas, on the maps below.
    (2) Within these areas, the primary constituent elements of the 
physical or biological features essential to the conservation of 
Georgetown salamander consist of four components:
    (i) Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Georgetown salamander prey base). Hydrologic regimes 
similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow for subterranean sites. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 68.4 
and 69.8[emsp14][deg]F (20.2 and 21.0 [deg]C), dissolved oxygen 
concentrations between 6 and 8 milligrams per liter, and specific water

[[Page 50831]]

conductivity between 604 and 721 microsiemens per centimeter.
    (ii) Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat must be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
must have minimal sedimentation.
    (iii) Aquatic invertebrates for food. The spring and cave 
environments must be capable of supporting a diverse aquatic 
invertebrate community that includes crustaceans and insects.
    (iv) Subterranean aquifer. During periods of drought or dewatering 
on the surface in and around spring sites, access to the subsurface 
water table must be provided for shelter and protection.
    (3) Surface critical habitat includes the spring outlets and 
outflow up to the high water line and 164 ft (50 m) of downstream 
habitat, but does not include manmade structures (such as buildings, 
aqueducts, runways, roads, and other paved areas) and the land on which 
they are located existing within the legal boundaries on the effective 
date of this rule; however, the subterranean aquifer may extend below 
such structures. The subterranean critical habitat includes underground 
features in a circle with a radius of 984-ft (300-m) around the 
springs.
    (4) Critical habitat map units. Data layers defining map units were 
created using a geographic information system (GIS), which included 
species locations, roads, property boundaries, 2011 aerial photography, 
and USGS 7.5' quadrangles. Points were placed on the GIS. We delineated 
critical habitat unit boundaries by starting with the cave or spring 
point locations that are occupied by the salamanders. From these cave 
or springs points, we delineated a 984 ft (300 m) buffer to create the 
polygons that capture the extent to which we believe the salamander 
populations exist through underground conduits. The polygons were then 
simplified to reduce the number of vertices, but still retain the 
overall shape and extent. Subsequently, polygons that were within 98 ft 
(30 m) of each other were merged together. Each new merged polygon was 
then revised to remove extraneous divits or protrusions that resulted 
from the merge process. The maps in this entry, as modified by any 
accompanying regulatory text, establish the boundaries of the critical 
habitat designation. The coordinates or plot points or both on which 
each map is based are available to the public at the field office 
Internet site (at Docket No. FWS-R2-ES-2012-0035 and at the Service's 
Austin Ecological Services Field Office. You may obtain field office 
location information by contacting one of the Service regional offices, 
the addresses of which are listed at 50 CFR 2.2.
    (5) Index map follows:
    [GRAPHIC] [TIFF OMITTED] TP22AU12.001
    
    (6) Unit 1: Cobb Unit, Williamson County, Texas. Map of Unit 1 
follows:

[[Page 50832]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.002

    (7) Unit 2: Cowen Creek Spring Unit, Williamson County, Texas. Map 
of Units 2 and 3 follows:

[[Page 50833]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.003

    (8) Unit 3: Bat Well Unit, Williamson County, Texas. Map of Units 2 
and 3 is provided at paragraph (7) of this entry.
    (9) Unit 4: Walnut Spring Unit,Williamson County, Texas. Map of 
Units 4 and 5 follows:

[[Page 50834]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.004

    (10) Unit 5: Twin Springs Unit, Williamson County, Texas. Map of 
Units 4 and 5 is provided at paragraph (9) of this entry.
    (11) Unit 6: Hogg Hollow Spring Unit, Williamson County, Texas. Map 
of Units 6, 7, 8, and 9 follows:

[[Page 50835]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.005

    (12) Unit 7: Cedar Hollow Spring Unit, Williamson County, Texas. 
Map of Units 6, 7, 8, and 9 is provided at paragraph (11) of this 
entry.
    (13) Unit 8: Lake Georgetown Unit, Williamson County, Texas. Map of 
Units 6, 7, 8, and 9 is provided at paragraph (11) of this entry.
    (14) Unit 9: Water Tank Cave Unit, Williamson County, Texas. Map of 
Units 6, 7, 8, and 9 is provided at paragraph (11) of this entry.
    (15) Unit 10: Avant Spring Unit, Williamson County, Texas. Map of 
Units 10, 11, 12, and 13 follows:

[[Page 50836]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.006

    (16) Unit 11: Buford Hollow Spring Unit, Williamson County, Texas. 
Map of Units 10, 11, 12, 13 is provided at paragraph (15) of this 
entry.
    (17) Unit 12: Swinbank Spring Unit, Williamson County, Texas. Map 
of Units 10, 11, 12, and 13 is provided at paragraph (15) of this 
entry.
    (18) Unit 13: Shadow Canyon Unit, Williamson County, Texas. Map of 
Units 10, 11, 12, and 13 is provided at paragraph (15) of this entry.
    (19) Unit 14: San Gabriel Springs Unit, Williamson County, Texas. 
Map of Unit 14 follows:

[[Page 50837]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.007

Jollyville Plateau Salamander (Eurycea tonkawae)
    (1) Critical habitat units are depicted for Travis and Williamson 
Counties, Texas, on the maps below.
    (2) Within these areas, the primary constituent elements of the 
physical or biological features essential to the conservation of 
Jollyville Plateau salamander consist of four components:
    (i) Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Jollyville Plateau salamander's prey base). Hydrologic 
regimes similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow in subterranean habitats. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 65.3 
and 67.3[emsp14][deg]F (18.5 and 19.6 [deg]C), dissolved oxygen 
concentrations between 5.6 and 7.1 milligrams per liter, and specific 
water conductance between 550 and 625 microsiemens per centimeter.
    (ii) Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or

[[Page 50838]]

gravel) in the substrate of the salamander's surface aquatic habitat 
must be large enough to provide salamanders with cover, shelter, and 
foraging habitat. The substrate and interstitial spaces must have 
minimal sedimentation.
    (iii) Aquatic invertebrates for food. The spring and cave 
environments must be capable of supporting a diverse aquatic 
invertebrate community that includes crustaceans and insects.
    (iv) Subterranean aquifer. During periods of drought or dewatering 
on the surface in and around spring sites, access to the subsurface 
water table must be provided for shelter and protection.
    (3) Surface critical habitat includes the spring outlets and 
outflow up to the high water line and 164 ft (50 m) of downstream 
habitat, but does not include manmade structures (such as buildings, 
aqueducts, runways, roads, and other paved areas) and the land on which 
they are located existing within the legal boundaries on the effective 
date of this rule; however, the subterranean aquifer may extend below 
such structures. The subterranean critical habitat includes underground 
features in a circle with a radius of 984 ft (300 m) around the 
springs.
    (4) Critical habitat map units. Data layers defining map units were 
created using a geographic information system (GIS), which included 
species locations, roads, property boundaries, 2011 aerial photography, 
and USGS 7.5' quadrangles. Points were placed on the GIS. We delineated 
critical habitat unit boundaries by starting with the cave or spring 
point locations that are occupied by the salamanders. From these cave 
or springs points, we delineated a 984-ft (300-m) buffer to create the 
polygons that capture the extent to which we believe the salamander 
populations exist through underground conduits. The polygons were then 
simplified to reduce the number of vertices, but still retain the 
overall shape and extent. Subsequently, polygons that were within 98 ft 
(30 m) of each other where merged together. Each new merged polygon was 
then revised to remove extraneous divits or protrusions that resulted 
from the merge process. The maps in this entry, as modified by any 
accompanying regulatory text, establish the boundaries of the critical 
habitat designation. The coordinates or plot points or both on which 
each map is based are available to the public at the field office 
Internet site (http://www.fws.gov/southwest/es/AustinTexas/), http://www.regulations.gov at Docket No. FWS-R2-ES-2012-0035 and at the 
Service's Austin Ecological Services Field Office. You may obtain field 
office location information by contacting one of the Service regional 
offices, the addresses of which are listed at 50 CFR 2.2.
    (5) Index map follows:
    [GRAPHIC] [TIFF OMITTED] TP22AU12.008
    
    (6) Unit 1: Krienke Spring Unit, Williamson County, Texas. Map of 
Unit 1 follows:

[[Page 50839]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.009

    (7) Unit 2: Brushy Creek Spring Unit, Williamson County, Texas. Map 
of Unit 2 follows:

[[Page 50840]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.010

    (8) Unit 3: Testudo Tube Cave Unit, Williamson and Travis Counties, 
Texas. Map of Units 3, 4, and 5 follows:

[[Page 50841]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.011

    (9) Unit 4: Buttercup Creek Cave Unit, Travis and Williamson 
County, Texas. Map of Units 3, 4, and 5 is provided at paragraph (8) of 
this entry.
    (10) Unit 5: Treehouse Cave Unit, Williamson County, Texas. Map of 
Units 3, 4, and 5 is provided at paragraph (8) of this entry.
    (11) Unit 6: Avery Spring Unit, Williamson County, Texas. Map of 
Unit 6 follows:

[[Page 50842]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.012

    (12) Unit 7: PC Spring Unit, Williamson County, Texas. Map of Unit 
7 follows:

[[Page 50843]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.013

    (13) Unit 8: Baker and Audubon Spring Unit, Travis County, Texas, 
Map of Unit 8 follows:

[[Page 50844]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.014

    (14) Unit 9: Wheless Spring Unit, Travis County, Texas. Map of 
Units 9 and 10 follows:

[[Page 50845]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.015

    (15) Unit 10: Blizzard R-Bar-B Spring Unit, Travis County, Texas. 
Map of Units 9 and 10 in provided at paragraph (14) of this entry.
    (16) Unit 11: House Spring Unit, Travis County, Texas. Map of Units 
11, 12, and 13 follows:

[[Page 50846]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.016

    (17) Unit 12: Kelly Hollow Spring Unit, Travis County, Texas. Map 
of Units 11, 12, and 13 is provided at paragraph (16) of this entry.
    (18) Unit 13: MacDonald Well Unit, Travis County, Texas. Map of 
Units 11, 12, and 13 is provided at paragraph (16) of this entry.
    (19) Unit 14: Kretschmarr Unit, Travis County, Texas. Map of Units 
14, 15, 16, 17, 18, 19, 20, and 21 follows:

[[Page 50847]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.017

    (20) Unit 15: Pope and Hiers Spring Unit, Travis County, Texas. Map 
of Units 14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph 
(19) of this entry.
    (21) Unit 16: Fern Gully Spring Unit, Travis County, Texas. Map of 
Units 14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) 
of this entry.
    (22) Unit 17: Bull Creek 1 Unit, Travis County, Texas. Map of Units 
14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) of 
this entry.
    (23) Unit 18: Bull Creek 2 Unit, Travis County, Texas. Map of Units 
14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) of 
this entry.
    (24) Unit 19: Bull Creek 3 Unit, Travis County, Texas. Map of Units 
14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) of 
this entry.
    (25) Unit 20: Moss Gulley Spring Unit, Travis County, Texas. Map of 
Units 14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) 
of this entry.
    (26) Unit 21: Ivanhoe Spring Unit, Travis County, Texas. Map of 
Units 14, 15, 16, 17, 18, 19, 20, and 21 is provided at paragraph (19) 
of this entry.
    (27) Unit 22: Sylvia Spring Unit, Travis County, Texas. Map of 
Units 22, 23, 24, and 33 follows:

[[Page 50848]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.018

    (28) Unit 23: Tanglewood Spring Unit, Travis County, Texas. Map of 
Units 22, 23, 24, and 33 is provided at paragraph (27) of this entry.
    (29) Unit 24: Long Hog Hollow Unit, Travis County, Texas. Map of 
Units 22, 23, 24, and 33 is provided at paragraph (27) of this entry.
    (30) Unit 25: Tributary 3 Unit, Travis County, Texas. Map of Units 
25, 26, and 27 follows:

[[Page 50849]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.019

    (31) Unit 26: Sierra Spring Unit, Travis County, Texas. Map of 
Units 25, 26, and 27 is provided at paragraph (30) of this entry.
    (32) Unit 27: Troll Spring Unit, Travis County, Texas. Map of Units 
25, 26, and 27 is provided at paragraph (30) of this entry.
    (33) Unit 28: Stillhouse Unit, Travis County, Texas. Map of Units 
28, 29, 30, and 31 follows:

[[Page 50850]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.020

    (34) Unit 29: Salamander Cave Unit, Travis County, Texas. Map of 
Units 28, 29, 30, 31 is provided at paragraph (33) of this entry.
    (35) Unit 30: Indian Spring Unit, Travis County, Texas. Map of 
Units 28, 29, 30, and 31 is provided at paragraph (33) of this entry.
    (36) Unit 31: Spicewood Spring Unit, Travis County, Texas. Map of 
Units 28, 29, 30, and 31 is provided at paragraph (33) of this entry.
    (37) Unit 32: Balcones District Park Spring Unit, Travis County, 
Texas. Map of Unit 32 follows:

[[Page 50851]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.021

    (38) Unit 33: Tributary 4 Unit, Travis County, Texas. Map of Units 
22, 23, 24, and 33 is provided at paragraph (27) of this entry.
* * * * *
Salado Salamander (Eurycea chisholmensis)
    (1) Critical habitat units are depicted for Bell County, Texas, on 
the maps below.
    (2) Within these areas, the primary constituent elements of the 
physical or biological features essential to the conservation of Salado 
salamander consist of four components:
    (i) Water from the Northern Segment of the Edwards Aquifer. The 
groundwater must be similar to natural aquifer conditions both 
underground and as it discharges from natural spring outlets. 
Concentrations of water quality constituents that could have a negative 
impact on the salamander should be below levels that could exert direct 
lethal or sublethal effects (such as effects to reproduction, growth, 
development, or metabolic processes), or indirect effects (such as 
effects to the Salado salamander's prey base). Hydrologic regimes 
similar to the historical pattern of the specific sites must be 
present, with at least temporal surface flow for spring sites and 
continuous flow for subterranean sites. The water chemistry must be 
similar to natural aquifer conditions, with temperatures between 65.3 
and 69.8[emsp14][deg]F (18.5 and 21.0 [deg]C), dissolved oxygen

[[Page 50852]]

concentrations between 5.6 and 8 milligrams per liter, and conductivity 
between 550 and 721 microsiemens per centimeter.
    (ii) Rocky substrate with interstitial spaces. Rocks (boulders, 
cobble, or gravel) in the substrate of the salamander's surface aquatic 
habitat must be large enough to provide salamanders with cover, 
shelter, and foraging habitat. The substrate and interstitial spaces 
must have minimal sedimentation.
    (iii) Aquatic invertebrates for food. The spring and cave 
environments must be capable of supporting a diverse aquatic 
invertebrate community that includes crustaceans and insects.
    (iv) Subterranean aquifer. During periods of drought or dewatering 
on the surface in and around spring sites, access to the subsurface 
water table must be provided for shelter and protection.
    (3) Surface critical habitat includes the spring outlets and 
outflow up to the high water line and 164 ft (50 m) of downstream 
habitat, but does not include manmade structures (such as buildings, 
aqueducts, runways, roads, and other paved areas) and the land on which 
they are located existing within the legal boundaries on the effective 
date of this rule; however, the subterranean aquifer may extend below 
such structures. The subterranean critical habitat includes underground 
features in a circle with a radius of 984 ft (300 m) around the 
springs.
    (4) Critical habitat map units. Data layers defining map units were 
created using a geographic information system (GIS), which included 
species locations, roads, property boundaries, 2011 aerial photography, 
and USGS 7.5' quadrangles. Points were placed on the GIS. We delineated 
critical habitat unit boundaries by starting with the cave or spring 
point locations that are occupied by the salamanders. From these cave 
or springs points, we delineated a 984-ft (300-m) buffer to create the 
polygons that capture the extent to which we believe the salamander 
populations exist through underground conduits. The polygons were then 
simplified to reduce the number of vertices, but still retain the 
overall shape and extent. Subsequently, polygons that were within 98 ft 
(30 m) of each other where merged together. Each new merged polygon was 
then revised to remove extraneous divits or protrusions that resulted 
from the merge process. The maps in this entry, as modified by any 
accompanying regulatory text, establish the boundaries of the critical 
habitat designation. The coordinates or plot points or both on which 
each map is based are available to the public at the field office 
Internet site (http://www.fws.gov/southwest/es/AustinTexas/), http://www.regulations.gov at Docket No. FWS-R2-ES-2012-0035 and at the 
Service's Austin Ecological Services Field Office. You may obtain field 
office location information by contacting one of the Service regional 
offices, the addresses of which are listed at 50 CFR 2.2.
    (5) Index map follows:
    [GRAPHIC] [TIFF OMITTED] TP22AU12.022
    
    (6) Unit 1: Hog Hollow Spring Unit, Bell County, Texas. Map of 
Units 1, 2, and 3 follows:

[[Page 50853]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.023

    (7) Unit 2: Solana Spring 1 Unit, Bell County, Texas. Map 
of Units 1, 2, and 3 is provided at paragraph (6) of this entry.
    (8) Unit 3: Cistern Spring Unit, Bell County, Texas. Map of Units 
1, 2, and 3 is provided at paragraph (6) of this entry.
    (9) Unit 4: IH-35 Unit, Bell County, Texas. Map of Unit 4 follows:

[[Page 50854]]

[GRAPHIC] [TIFF OMITTED] TP22AU12.024

* * * * *

    Dated: July 31, 2012.
Rachel Jacobson,
Principal Deputy Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 2012-19659 Filed 8-21-12; 8:45 am]
BILLING CODE 4310-55-C