[Federal Register Volume 72, Number 146 (Tuesday, July 31, 2007)]
[Proposed Rules]
[Pages 41679-41701]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-3678]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AV25


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for the Devils River Minnow

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 
designate critical habitat for the Devils River minnow (Dionda diaboli) 
under the Endangered Species Act of 1973, as amended (Act). In total, 
approximately 73.5 stream kilometers (km) (45.7 stream miles (mi)) are 
within the boundaries of the proposed critical habitat designation. The 
proposed critical habitat is located along streams in Val Verde and 
Kinney Counties, Texas.

DATES: We will accept comments from all interested parties until 
October 1, 2007. We must receive requests for public hearings, in 
writing, at the address shown in the ADDRESSES section by September 14, 
2007.

ADDRESSES: If you wish to comment on the proposed rule, you may submit 
your comments and materials by any one of several methods:
    1. You may mail or hand-deliver written comments and information to 
Adam Zerrenner, Field Supervisor, U.S. Fish and Wildlife Service, 
Austin Ecological Services Field Office, 10711 Burnet Road, Suite 200, 
Austin, TX 78758.
    2. You may send comments by electronic mail (e-mail) to [email protected]. Please see the Public Comments Solicited section below for 
file format and other information about electronic filing.
    3. You may fax your comments to the attention of Adam Zerrenner at 
512-490-0974.
    4. You may go to the Federal eRulemaking Portal: http://www.regulations.gov. Follow the instructions for submitting comments.
    Comments and materials received, as well as supporting 
documentation used in the preparation of this proposed rule, will be 
available for public inspection, by appointment, during normal business 
hours at the Austin Ecological Services Field Office, 10711 Burnet 
Road, Suite 200, Austin, TX 78758; telephone 512-490-0057.

FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, Field Supervisor, 
Austin Ecological Services Field Office, 10711 Burnet Road, Suite 200, 
Austin, TX 78758; telephone 512-490-0057; 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, 7 days a 
week and 24 hours a day.

SUPPLEMENTARY INFORMATION:

Public Comments Solicited

    We intend that any final action resulting from this proposal will 
be as accurate and as effective as possible. Therefore, comments or 
suggestions from the public, other concerned governmental agencies, the 
scientific community, industry, or any other interested party 
concerning this proposed rule are hereby solicited. Comments 
particularly are sought concerning:
    (1) The reasons habitat should or should not be designated as 
critical habitat under section 4 of the Act (16 U.S.C. 1531 et seq.), 
including whether the benefit of designation would outweigh any threats 
to the species caused by designation such that the designation of 
critical habitat is prudent;
    (2) Specific information on the amount and distribution of Devils 
River minnow habitat, what areas should be included in the designation 
that were occupied at the time of listing that contain the features 
that are essential for the conservation of the species and why, and 
what areas that were not occupied at the listing are essential to the 
conservation of the species and why;
    (3) Information on the status of the Devils River minnow in 
Sycamore Creek and Las Moras Creek watersheds and information that 
indicates whether or not these areas should be considered essential to 
the conservation of the species;
    (4) Land use designations and current or planned activities in the 
subject areas and their possible impacts on proposed critical habitat;
    (5) Any foreseeable economic, national security, or other potential 
impacts resulting from the proposed designation and, in particular, any 
impacts on small entities and information about the benefits of 
including or excluding any areas that exhibit those impacts; and
    (6) Whether our approach to designating critical habitat could be 
improved or modified in any way to provide for greater public 
participation and understanding, or to assist us in accommodating 
public concerns and comments.
    You may submit comments and materials concerning this proposal by 
one of several methods (see ADDRESSES). Please include ``Attn: Devils 
River minnow'' in your e-mail subject header and your name and return 
address in the body of your message. If you do not receive a 
confirmation from the system that we have received your message, 
contact us directly by calling our Austin Ecological Services Field 
Office at 512-490-0057. Please note that comments must be received by 
the date specified in the DATES section in order to be considered and 
that the e-mail address [email protected] will be closed out at the 
termination of the public comment period.
    Before including your address, phone number, e-mail address, or 
other personal identifying information in your comment, you should be 
aware that your entire comment--including your personal identifying 
information--may be made publicly available at any time. While you can 
ask us in your comment to withhold your personal identifying 
information from public review, we cannot guarantee that we will be 
able to do so.

Background

    It is our intent to discuss only those topics directly relevant to 
the designation of critical habitat in this proposed rule. For more 
information on

[[Page 41680]]

the Devils River minnow, refer to the final listing rule published in 
the Federal Register on October 20, 1999 (64 FR 56596) or the 2005 
Devils River Minnow Recovery Plan available online at http://www.fws.gov/endangered/. More detailed information on Devils River 
minnow biology and ecology that is directly relevant to designation of 
critical habitat is discussed under the Primary Constituent Elements 
section below.

Description and Taxonomy

    The Devils River minnow (Dionda diaboli Hubbs and Brown) is a small 
fish first collected in 1951 (Hubbs and Brown 1956, p. 70). The Devils 
River minnow is recognized as a distinct species by the American 
Fisheries Society (Nelson et al. 2004, p. 70). Taxonomic validity is 
based on morphology (Hubbs and Brown 1956, p. 69), genetic markers 
(Mayden et al. 1992, p. 722), and chromosome differences (Gold et al. 
1992, p. 221).
    Adult Devils River minnows reach sizes of 25-53 millimeters (mm) 
(1.0-2.1 inches (in)) standard length. The fish has a wedge-shaped spot 
near the tail and a pronounced lateral stripe extending through the eye 
to the snout but without reaching the lower lip. The species has a 
narrow head and prominent dark markings on the scale pockets of the 
body above the lateral line, producing a crosshatched appearance when 
viewed from above (Hubbs and Brown 1956, pp. 69-70). The species occurs 
with other minnows, such as the closely related manantial roundnose 
minnow (Dionda argentosa).

Distribution and Habitat

    The Devils River minnow is limited to short stretches of spring-fed 
stream tributaries of the Rio Grande in southwestern Texas and 
northeastern Mexico (Garrett et al. 1992, p. 259). In the United 
States, the fish has never been found outside of five streams in Val 
Verde and Kinney Counties, Texas. The Devils River minnow currently 
occurs in stretches of the Devils River, San Felipe Creek, and Pinto 
Creek. It has been extirpated from Las Moras Creek and has not been 
collected from Sycamore Creek since 1989 (Garrett et al. 1992, pp. 261-
267; Garrett et al. 2004, p. 435). There is little information 
available on the status of the Devils River minnow in Mexico. 
Historically, it was known to occur in the R[iacute]o San Carlos and 
several streams in the R[iacute]o Salado Drainage, in the State of 
Coahuila. Regulations at 50 CFR 424.12(h) state that critical habitat 
shall not be designated within foreign countries or in other areas 
outside of United States jurisdiction. As such, geographical areas 
supporting the Devils River minnow in Mexico are not included in the 
proposed critical habitat designation.
    The Devils River minnow is found only in spring-fed streams (Brune 
1981, pp. 274-275, 450-454; Garrett et al. 1992, p. 259) with shallow 
to moderate depths and slow to moderate water velocity over gravel 
substrates. Within these streams, Devils River minnows are most often 
found within or nearby emergent aquatic plants (Garrett et al. 2004, p. 
437) or near similar structures created by stream bank vegetation that 
extends into the water (Lopez-Fernandez and Winemiller 2005, p. 249).

Previous Federal Actions

    The Devils River minnow was listed as threatened on October 20, 
1999 (64 FR 56596). Critical habitat was not designated for this 
species at the time of listing (64 FR 56606). On October 5, 2005, the 
Forest Guardians, Center for Biological Diversity, and Save Our Springs 
Alliance filed suit against the Service for failure to designate 
critical habitat for this species (Forest Guardians et al. v. Hall 
2005). On June 28, 2006, a settlement was reached that requires the 
Service to re-evaluate our original prudenct determination. The 
settlement stipulated that, if prudent, a proposed rule would be 
submitted to the Federal Register for publication on or before July 31, 
2007, and a final rule by July 31, 2008. This proposed rule complies 
with the settlement agreement and with section 4(b)(2) of the Act. For 
more information on previous Federal actions concerning the Devils 
River minnow, refer to the final listing rule published in the Federal 
Register on October 20, 1999 (64 FR 56598).

Critical Habitat

    Critical habitat is defined in section 3 of the Act as (i) the 
specific areas within the geographical area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas outside the 
geographical area occupied by a 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 any endangered species or threatened species to the point at 
which the measures provided pursuant to the Act are no longer 
necessary.
    Critical habitat receives protection under section 7(a)(2) of the 
Act through the prohibition against destruction or adverse modification 
of critical habitat with regard to actions carried out, funded, or 
authorized by a Federal agency. Section 7 of the Act requires 
consultation on Federal actions that may affect 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 government or public 
access to private lands. Section 7(a)(2) of the Act is a purely 
protective measure and does not require implementation of restoration, 
recovery, or enhancement measures.
    To be included in a critical habitat designation, the habitat 
within the geographical area occupied by the species must first have 
features that are essential to the conservation of the species. 
Critical habitat designations identify, to the extent known using the 
best scientific data available, habitat areas that provide essential 
life cycle needs of the species (i.e., areas on which are found the 
primary constituent elements, as defined at 50 CFR 424.12(b)).
    Occupied habitat that contains the features essential to the 
conservation of the species meets the definition of critical habitat 
only if the essential features thereon may require special management 
considerations or protection. Thus, we do not include areas where 
existing management is sufficient to conserve the species. (As 
discussed below, such areas may also be excluded from critical habitat 
pursuant to section 4(b)(2) of the Act.) Unoccupied areas can be 
designated as critical habitat. However, when the best available 
scientific data do not demonstrate that the conservation needs of the 
species require additional areas, we will not designate critical 
habitat in areas outside the geographical area occupied by the species.
    Section 4 of the Act requires that we designate critical habitat on 
the basis of the best scientific and commercial data available. 
Further, the Service's Policy on Information Standards Under the 
Endangered Species Act, published in the Federal Register on July 1, 
1994 (59 FR 34271), and Section 515 of the Treasury and General 
Government Appropriations Act for Fiscal Year 2001 (P.L. 106-554; H.R. 
5658), and the associated Information Quality Guidelines issued by the 
Service, provide criteria, establish procedures, and provide guidance 
to ensure that

[[Page 41681]]

decisions made by the Service represent the best scientific data 
available. They require Service 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 determining which 
areas are critical habitat, a primary source of information is 
generally the listing package for the species. Additional information 
sources 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, or other 
unpublished materials and expert opinion or personal knowledge. All 
information is used in accordance with the provisions of Section 515 of 
the Treasury and General Government Appropriations Act for Fiscal Year 
2001 (P.L. 106-554; H.R. 5658) and the associated Information Quality 
Guidelines issued by the Service.
    Habitat is often dynamic, and species may move from one area to 
another over time. Furthermore, we recognize that designation of 
critical habitat may not include all of the habitat areas that may 
eventually be determined to be necessary for the recovery of the 
species. For these reasons, critical habitat designations do not signal 
that habitat outside the designation is unimportant or may not be 
required for recovery.
    Areas that support populations, but are outside the critical 
habitat designation, will continue to be subject to conservation 
actions implemented under section 7(a)(1) of the Act and to the 
regulatory protections afforded by the section 7(a)(2) jeopardy 
standard, as determined on the basis of the best available information 
at the time of the action. Federally funded or permitted projects 
affecting listed species outside their designated critical habitat 
areas may still result in jeopardy findings in some cases. 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, or 
other species conservation planning efforts if new information 
available to these planning efforts calls for a different outcome.

Methods

    As required by section 4(b) of the Act, we use the best scientific 
data available in determining areas occupied at the time of listing 
that contain the features essential to the conservation of the Devils 
River minnow, and areas unoccupied at the time of listing that are 
essential to the conservation of the Devils River minnow, or both. In 
designating critical habitat for the Devils River minnow, we reviewed 
the relevant information available, including peer-reviewed journal 
articles, unpublished reports, the Devils River Minnow Recovery Plan, 
the final listing rule, and unpublished materials (such as expert 
opinions). In February 2006, we sent information requests to a large 
number of experts and stakeholders (such as private landowners, Texas 
state government agencies, other Federal agencies, local governments, 
and nongovernmental organizations).
    We have also reviewed available information that pertains to the 
habitat requirements of this species. We used a wide variety of sources 
of information, such as material included in reports submitted during 
section 7 consultations; research published in peer-reviewed articles 
and presented in academic theses; research proposals and correspondence 
from technical experts; data and reports from other State and Federal 
agencies; unpublished data such as field notes and personal 
observations from field biologists; and regional Geographic Information 
System (GIS) coverages, including geodatabases provided by partner 
organizations, such as the City of Del Rio and The Nature Conservancy.
    We are proposing to designate critical habitat for the Devils River 
minnow in areas that were occupied at the time of listing, and that 
contain the physical and biological features essential to the 
conservation of the species arranged in the quantity and spatial 
characteristics necessary for conservation (see ``Criteria Used to 
Identify Critical Habitat'' section below). We are also proposing to 
designate critical habitat in areas unoccupied at the time of listing 
and determined to be essential to the conservation of the Devils River 
minnow.

Primary Constituent Elements

    In accordance with section 3(5)(A)(i) of the Act and regulations at 
50 CFR 424.12, in determining which areas to propose as critical 
habitat, we consider those physical and biological features (primary 
constituent elements) that are essential to the conservation of the 
species, and within areas occupied by the species at the time of 
listing, that may require special management considerations and 
protection. These include, but are not limited to, space for individual 
and population growth and for normal behavior; food, water, air, light, 
minerals, or other nutritional or physiological requirements; cover or 
shelter; sites for breeding, reproduction, and rearing (or development) 
of offspring; and habitats that are protected from disturbance or are 
representative of the historic geographical and ecological 
distributions of a species.
    The specific physical and biological features essential to the 
conservation of the Devils River minnow, primary constituent elements 
(PCEs), are derived from the biological needs of the species as 
understood from studies of its biology and ecology, including but not 
limited to, Edwards et al. (2004), Garrett et al. (1992), Garrett et 
al. (2004), Gibson et al. (2004), Harrell (1978), Hubbs (2001), Hubbs 
and Garrett (1990), Lopez-Fernandez and Winemiller (2005), Valdes Cantu 
and Winemiller (1997), and Winemiller (2003).

Space for Individual and Population Growth, Normal Behavior, and Cover

    The Devils River minnow is a fish that occurs only in aquatic 
environments of small to mid-sized streams that are tributaries to the 
Rio Grande. The species spends its full life cycle within streams. The 
stream environment provides all of the space necessary to allow for 
individual and population growth, food, cover, and normal behaviors of 
the species. Quantitative studies of the specific micro-habitats used 
by any life stages of Devils River minnow in the wild have not been 
conducted. Studies of fish habitat within its range have found too few 
individuals of Devils River minnow to analyze specific habitat 
associations (Garrett et al. 1992, p. 266; Valdes Cantu and Winemiller 
1997, p. 268; Robertson and Winemiller 2003, p. 119). However, 
observational studies have been conducted throughout its limited range 
that qualitatively defined stream conditions where Devils River minnows 
have been collected.
    General habitat descriptions of areas where Devils River minnow 
have been found include the following: ``the area where spring runs 
enter the river'' (Hubbs and Garrett 1990, p. 448); ``channels of fast-
flowing water over gravel bottoms'' (Garrett et al. 1992, p. 259); 
``associated with water willow (Justicia americana) and other aquatic 
macrophytes over a gravel-cobble substrate'' (Garrett et al. 2004, p. 
437) (macrophytes are plants large enough to be seen without a 
microscope); and ``stream seeps'' at sites that ``had abundant riparian 
vegetation overhanging the banks'' (Lopez-Fernandez and Winemiller 
2005, p. 249). We based our determinations of the PCEs on the physical 
and biological features that have been measured in

[[Page 41682]]

streams where Devils River minnow occur.
    a. Water Depth and Velocity. Flowing water within streams is 
critical to provide living space for the Devils River minnow. All of 
the streams where the Devils River minnow is found are supported by 
springs that derive their discharge from underground aquifers, either 
the Edwards Aquifer or the Edwards-Trinity Aquifer (Brune 1981, pp. 
274-277, 449-456; Edwards et al. 2004, p. 256; Garrett et al. 1992, p. 
261; Garrett et al. 2004, p. 439; Hubbs and Garrett 1990, p. 448; 
Lopez-Fernandez and Winemiller 2005, p. 249). The Devils River minnow 
has been associated within the stream channel with areas with slow to 
moderate velocities between 10 and 40 centimeters (cm)/second (4 and 16 
inches (in)/second) (Winemiller 2003, p. 13). The Devils River minnow 
is usually found in areas with shallow to moderate water depths between 
about 10 cm (4 in) and 1.5 meters (4.9 feet (ft)) (Garrett et al. 2004, 
p. 436). Appropriate water depths and velocities are required physical 
features for Devils River minnows to complete all life history 
functions.
    b. Cover. The presence of vegetative structure appears to be 
particularly important for the Devils River minnow. Garrett et al. 
(2004, p. 437) states that the species is most often found associated 
with emergent or submerged vegetation. Lopez-Fernandez and Winemiller 
(2005, p. 249) also found the Devils River minnow associated with 
stream banks having riparian vegetation that overhangs into the water 
column, presumably providing similar structure for the fish to use as 
cover. The structure provided by vegetation likely serves as cover for 
predator avoidance by the Devils River minnow and as a source of food 
where algae and other microorganisms may be attached. In controlled 
experiments in an artificial stream setting, minnows in the Dionda 
genus (the experiment did not distinguished between the Devils River 
minnow and the closely related manantial roundnose minnow) were found 
consistently associated with plants, and, in the presence of a 
predator, sought shelter in plant substrate habitat (Thomas 2001, p. 
8). Also, laboratory observations by Gibson et al. (2004, p. 42) 
suggested that spawning only occurred when structure was provided in 
aquaria. Instream vegetative structure is an important biological 
feature for the Devils River minnow to avoid predation and complete 
other normal behaviors, such as feeding and spawning.
    c. Substrates. The Devils River minnow is most often associated 
with substrates (stream bottom) described as gravel and cobble (Garrett 
et al. 2004, p. 436). Lopez-Fernandez and Winemiller (2005, p. 248) 
found the Devils River minnow associated with areas where the amounts 
of fine sediment on stream bottoms were low (less than 65 percent 
stream bottom coverage) (Winemiller 2003, p. 13) and where there was 
low or moderate amounts of substrate embeddedness. The term 
embeddedness is defined by Sylte and Fischenich (2003, p. 1) as the 
degree to which fine sediments surround coarse substrates on the 
surface of a streambed. Low levels of substrate embeddedness and low 
amounts of fine sediment are physical stream features that provide 
interstitial spaces where microorganisms grow. These microorganisms are 
a component of the diet of the Devils River minnow (Lopez-Fernandez and 
Winemiller 2005, p. 250). We estimate substrate sizes for gravel-cobble 
between 2 and 10 cm (0.8 and 4 in) in diameter (Cummins 1962, p. 495) 
are important for supporting food sources for the Devils River minnow.
    d. Stream Channel. The Devils River minnow occurs in the waters of 
stream channels that flow out of the Edwards Plateau of Texas. The 
streams contain a variety of mesohabitats for fish that are temporally 
and spatially dynamic (Harrell 1978, p. 60-61; Robertson and Winemiller 
2003, p. 115). Mesohabitat types are stream conditions with different 
combinations of depth, velocity, and substrate, such as pools (stream 
reaches with low velocity and deep water), riffles (stream reaches with 
moderate velocity and shallow depths and some turbulence due to high 
gradient), runs (stream reaches with moderate depths and moderate 
velocities and a uniformly, flat stream bottom), and backwaters (areas 
in streams with little or no velocities along stream margins) 
(Parasiewicz 2001, p. 7). These physical conditions in stream channels 
are mainly formed by large flood events that shape the banks and alter 
stream beds. Healthy stream ecosystems require intact natural stream 
banks (composed of sediments, rocks, and native vegetation) and stream 
beds (dynamically fluctuating from silt, sand, gravel, cobble, and 
bedrock). These physical features allow natural ecological processes in 
stream ecosystems to maintain habitat for Devils River minnow behaviors 
of feeding, breeding, and seeking shelter.
    Devils River minnow may move up and downstream to use diverse 
mesohabitats during different seasons and life stages, which could 
partially explain the highly variable sampling results assessing 
abundance of the fish (Garrett et al. 2002, p. 478). However, it is 
unknown to what extent Devils River minnow may move within occupied 
stream segments because no research on movement has been conducted. 
Linear movement (upstream or downstream) within streams may be 
important to allow fishes to complete life history functions and adjust 
to resource abundance, but this linear movement may often be 
underestimated due to limited biological studies (Fausch et al. 2002, 
p. 490). The Devils River minnow occurs in relatively short stream 
segments and, therefore, needs to be able to move within the stream 
unimpeded to prevent population fragmentation.

Food

    The Devils River minnow, like other minnows in the Dionda genus, 
has a long coiled gut for digesting algae and plants. Lopez-Fernandez 
and Winemiller (2005, p. 250) noted that Devils River minnow graze on 
algae attached to stream substrates (such as gravel, rocks, submerged 
plants, woody debris) and associated microorganisms. Thomas (2001, p. 
13) observed minnows in the Dionda genus (the experiment did not 
distinguish between Devils River minnow and the closely related 
manatial roundnose minnow) feeding extensively on filamentous algae 
growing on rocks and plants in an artificial stream experiment. The 
specific components of the Devils River minnow diet have not been 
investigated, but a study is underway to identify stomach contents of 
the Devils River minnow in San Felipe Creek (Texas Parks and Wildlife 
Department (TPWD) 2006, p. 1). An abundant aquatic food base is an 
essential biological feature for conservation of Devils River minnow.

Water Quality

    The Devils River minnow occurs in spring-fed streams originating 
from groundwater. The aquifers that support these streams are of high 
quality, free of pollution and most human-caused impacts (Plateau Water 
Planning Group (PWPG) 2006, p. 5-9). This region of Texas has limited 
human development that would compromise water quality of the streams 
where Devils River minnows occur (San Felipe Creek may be an exception, 
see ``Special Management Considerations or Protection'' below). The 
watersheds are largely rural and have been altered to some extent by 
livestock grazing (cattle, sheep, and goats) for many decades (Brune 
1981, p. 449). As part of state-wide water planning efforts, the TPWD

[[Page 41683]]

proposed that all five streams within the range of the Devils River 
minnow (Devils River, San Felipe Creek, Sycamore Creek, Pinto Creek, 
and Las Moras Creek) be considered ``ecologically significant stream 
segments'' for their biological function, hydrological function, 
exceptional aquatic life, and high aesthetic value (El-Hage and Moulton 
2001, pp. 28-36, 45-49).
    No specific studies have been conducted to determine water quality 
preferences or tolerances for Devils River minnow. However, because the 
species now occurs in only three streams, observations of water quality 
conditions in these streams are used to evaluate the needed water 
quality parameters for critical habitat. In addition, laboratory 
studies by Gibson et al. (2004, pp. 44-46) and Gibson and Fries (2005, 
pp. 299-303) have also provided useful information for the water 
quality conditions in captivity for Devils River minnow.
    a. Water temperature. Water temperatures from groundwater discharge 
at these springs are considered constant (Hubbs 2001, p. 324). However, 
water temperatures downstream from springs vary daily and seasonally 
(Hubbs 2001, p. 324). Water temperatures have been measured in these 
stream segments to range from about 17 [deg]C (degrees Celsius) to 29 
[deg]C (63 [deg]F (degrees Fahrenheit) to 85 [deg]F). Temperatures in 
the Devils River ranged from 17 [deg]C to 27 [deg]C (63 [deg]F to 81 
[deg]F) (Lopez-Fernandez and Winemiller 2005, p. 248; Hubbs 2001, p. 
312). Measurements in San Felipe Creek have ranged from 19 [deg]C to 24 
[deg]C (66 [deg]F to 75 [deg]F) (Hubbs 2001, p. 311; Winemiller 2003, 
p. 13). Gibson and Fries (2005, p. 296) had successful spawning by 
Devils River minnows at temperatures from about 18 [deg]C to 24 [deg]C 
(64 [deg]F to 75 [deg]F). Higher water temperatures are rare in Devils 
River minnow habitat, but temperatures up to 29 [deg]C (84 [deg]F) were 
recorded in Pinto Creek (Garrett et al. 2004, p. 437). This stream 
segment has the lowest flow of those known to contain the Devils River 
minnow, resulting in higher temperatures. Maintaining water 
temperatures within an acceptable range in small streams is an 
essential physical feature for the Devils River minnow to allow for 
survival and reproduction.
    b. Water chemistry. Researchers have noted the need for high-
quality water in habitats supporting the Devils River minnow (Garrett 
2003, p. 155). Field studies at sites where Devils River minnow have 
been collected in conjunction with water quality measurements have 
documented that habitats contain the following water chemistry: 
dissolved oxygen levels are greater than 5.0 mg/l (milligrams per 
liter) (Hubbs 2001, p. 312; Winemiller 2003, p. 13; Gibson et al. 2004, 
p. 44); pH ranges between 7.0 and 8.2 (Garrett et al. 2004, p. 440; 
Hubbs 2001, p. 312; Winemiller 2003, p. 13); conductivity is less than 
0.7 mS/cm (microseimens per centimeter) and salinity is less than 1 ppt 
(part per thousand) (Hubbs 2001, p. 312; Winemiller 2003, p. 13; 
Garrett et al. 2004, p. 440; Gibson et al. 2004, p. 45); and ammonia 
levels are less than 0.4 mg/l (Hubbs 2001, p. 312; Garrett et al. 2004, 
p. 440). Streams with water chemistry within the observed ranges are 
essential physical features to provide habitat for normal behaviors of 
Devils River minnow.
    Garrett et al. (2004, pp. 439-440) highlighted the conservation 
implications of water quality when describing the distribution of 
Devils River minnow in Pinto Creek. The species is abundant in upstream 
portions of the creek and is abruptly absent at and downstream from the 
Highway 90 Bridge crossing. A different aquifer (Austin Chalk) feeds 
the lower portion of the creek (Ashworth and Stein 2005, p. 19), which 
results in changes in water quality (lower measurements of water 
temperature, pH, ammonia, and salinity). Garrett et al. (2004, p. 439) 
found that the change in water quality also coincided with the 
occurrence of different fish species that were more tolerant of lower 
values for these water quality parameters.
    c. Pollution. The Devils River minnow occurs only in habitats that 
are generally free of human-caused pollution. Garrett et al. (1992, pp. 
266-267) suspected that the addition of chlorine to Las Moras Creek for 
the maintenance of a recreational swimming pool may have played a role 
in the extirpation of Devils River minnow from that system. Unnatural 
addition of pollutants such as copper, arsenic, mercury, and cadmium; 
human and animal waste products; pesticides; suspended sediments; 
petroleum compounds and gasoline or diesel fuels will alter habitat 
functions and threaten the continued existence of Devils River minnow. 
Fish, particularly herbivores and bottom-feeders, such as the Devils 
River minnow, are susceptible to the detrimental effects of aquatic 
pollutants (Buzan 1997, p. 4). Areas with waters free of pollution are 
essential physical features to allow normal behaviors and growth of the 
Devils River minnow and to maintain healthy populations of its food 
sources.

Sites for Breeding, Reproduction, and Rearing of Offspring

    The specific sites and habitat associated with Devils River minnow 
breeding and reproduction have not been documented in the wild. 
However, Gibson et al. (2004) studied preferred conditions for spawning 
by Devils River minnow in a laboratory setting. Gibson et al. (2004, 
pp. 45-46) documented that the species is a broadcast spawner (they 
release eggs and sperm into the open water), over unprepared substrates 
(they don't build nests), and males display some territorial behavior. 
Broadcast spawning is the most common reproductive method in minnows 
(Johnston 1999, p. 22; Johnston and Page 1992, p. 604). Fertilized eggs 
of Devils River minnow were slightly adhesive (or became more adhesive 
with time) and tended to stick to gravels just below the surface of the 
substrate (Gibson et al. 2004, p. 46). The eggs can hatch less than one 
week after deposition (Gibson 2007, p. 1). There was little seasonality 
in spawning periods observed (Gibson et al. 2004, p. 45-46), which is 
consistent with a species that lives in a relatively stable temperature 
environment, such as spring-fed streams with low seasonal temperature 
variations. Based on this information, it is likely the species can 
spawn during most of the year. This is supported by Garrett et al. 
(2004, p. 437), who observed distinct breeding coloration of Devils 
River minnow (blue sheen on the head and yellow tint on body) in Pinto 
Creek in December 2001, and Winemiller (2003, p. 16), who found 
juveniles from early spring to late fall in San Felipe Creek.
    a. Substrate. Gibson and Fries (2005, p. 299) found that Devils 
River minnow preferred gravel for spawning substrate, with size ranging 
mostly from 2 to 3 cm in diameter (0.8 to 1.2 in). Gravel and rock 
substrates are required physical features for spawning (depositing, 
incubating, and hatching) of Devils River minnow eggs.
    b. Cover. In laboratory experiments, Devils River minnow spawned in 
tanks with live potted plants (Vallisnaria spp. and Justicia spp.); 
however, eggs were never found on the plants or other parts of the tank 
(Gibson et al. 2004, pp. 42, 43, 46). The plants apparently served as 
cover for the fish and allowed favorable conditions for spawning to 
occur. This condition is supported by observations in the wild that 
associate Devils River minnow with aquatic habitats where vegetative 
structure is present. This vegetative structure is a biological feature 
that is important for reproduction of Devils River minnow.

[[Page 41684]]

Habitat Protected From Disturbance or Representative of the Historic 
Geographical and Ecological Distribution of a Species

    a. Nonnative species. The introduction and spread of nonnative 
species have been identified as major factors in the continuing decline 
of native fishes throughout North America (Moyle et al. 1986, pp. 415-
416) and particularly in the southwestern United States (Miller 1961, 
p. 397; Miller 1977, pp. 376-377). Williams et al. (1989, p. 1) 
concluded that nonnative species were a causal factor in 68 percent of 
the fish extinctions in North America in the last 100 years. For 70 
percent of those fish still extant, but considered to be endangered or 
threatened, introduced nonnative species are a primary cause of the 
decline (Lassuy 1995, p. 392). Nonnative species have been referenced 
as a cause of decline in native Texas fishes as well (Anderson et al. 
1995, p. 319; Hubbs 1990, p. 89; Hubbs et al. 1991, p. 2).
    Aquatic nonnative species are introduced and spread into new areas 
through a variety of mechanisms, intentional and accidental, authorized 
and unauthorized. Mechanisms for nonnative fish dispersal in Texas 
include sport fish stocking (intentional and inadvertent, non-target 
species), aquaculture escapes, aquarium releases, and bait bucket 
releases (release of fish used as bait by anglers) (Howells 2001, p. 
1).
    Within the range of the Devils River minnow, nonnative aquatic 
species of potential concern include: armored (or suckermouth) catfish 
(Hypostomus sp.) in San Felipe Creek (Lopez-Fernandez and Winemiller 
2005, pp. 246-251); smallmouth bass (Micropterus dolomieu) in the 
Devils River (Thomas 2001, p. 1); African cichlid (Oreochromis aureus) 
in San Felipe Creek (Lopez-Fernandez and Winemiller 2005, p. 249) and 
Devils River (Garrett et al. 1992, p. 266); Asian snail (Melanoides 
tuberculata) and associated parasites (McDermott 2000, pp. 13-14); and 
Asian bivalve mollusk (Corbicula sp.) (Winemiller 2003, p. 25) in San 
Felipe Creek. Effects from nonnative species can include predation, 
competition for resources, altering of habitat, changing of fish 
assemblages (combinations of species), or transmission of harmful 
diseases or parasites (Aquatic Nuisance Species Task Force 1994, pp. 
51-59; Baxter et al. 2004, p. 2656; Howells 2001, pp. 17-18; Light and 
Marchetti 2007, pp. 442-444; Moyle et al. 1986, pp. 416-418). Studies 
have found effects from the armored catfish in San Felipe Creek, most 
likely due to competition for food (Lopez-Fernandez and Winemiller 
2005, p. 250). The persistence of Devils River minnow in its natural 
range of habitats is dependent on areas that are devoid of harmful 
nonnative aquatic species or where nonnative aquatic species are at 
levels that allow healthy populations of the Devils River minnow. The 
absence of harmful nonnative species is an essential biological feature 
for conservation of the Devils River minnow.
    b. Hydrology. Natural stream flow regimes (both quantity and 
timing) are vital components to maintain ecological integrity in stream 
ecosystems (Poff et al. 1997, p. 769; Resh et al. 1988, pp. 443-444). 
Aquatic organisms, like the Devils River minnow, have specific 
adaptations to use the environmental conditions provided by natural 
flowing systems and the highly variable stream flow patterns (Lytle and 
Poff 2004, p. 94). As with other streams in the arid southwestern 
United States, streams where the Devils River minnow occurs can have 
large fluctuations in stream flow levels. In Texas, streams are 
characterized by high variation between large flood flows and extended 
period of low flows (Jones 1991, p. 513). Base flows in streams 
containing Devils River minnow are generally maintained by constant 
spring flows (Ashworth and Stein 2005, p. 4), but in periods of 
drought, especially in combination with groundwater withdrawals, 
portions of stream segments can be periodically dewatered. The 
occurrence of intermittent stream segments within the range of the 
Devils River minnow is most common in Pinto Creek (Ashworth and Stein 
2005, Figure 13; Uliana 2005, p. 4; Allan 2006, p. 1).
    Although portions of stream segments included in this proposed 
designation may experience short periods of low or no flows (causing 
dry sections of stream), they are still important because the Devils 
River minnow is adapted to stream systems with some fluctuating water 
levels. Fish cannot persist in dewatered areas (Hubbs 1990, p. 89). 
However, Devils River minnows will use dewatered areas that are 
subsequently wetted as connective corridors between occupied or 
seasonally occupied habitat. Fausch et al. (2002, p. 490) notes in a 
review of movement of fishes related to metapopulation dynamics that, 
``Even small fishes may move long distances to repopulate rewetted 
habitats.'' Preventing habitat fragmentation of fish populations is 
important in reducing extinction risks in rare species (Fagan 2002, p. 
3255). Areas within stream courses that may be periodically dewatered 
but that serve as connective corridors between occupied or seasonally 
occupied habitat and through which the species may move when the 
habitat is wetted are important physical features of Devils River 
minnow habitat.
    Flooding is also a large part of the natural hydrology of streams 
within the range of Devils River minnow. Large floods have been shown 
to alter fish community structure and fish habitat use in the Devils 
River (Harrell 1978, p. 67) and in San Felipe Creek (Garrett and 
Edwards 2003, p. 787; Winemiller 2003, p. 12). Pearsons et al. (1992, 
p. 427) states that ``Flooding is one of the most important abiotic 
factors that structure biotic assemblages in streams.'' Floods provide 
flushing flows that remove fine sediments from gravel and provide 
spawning substrates for species like the Devils River minnow (Instream 
Flow Council 2002, p. 103; Poff et al. 1997, p. 775). Flooding is the 
physical mechanism that shapes stream channels by a process known as 
scour and fill, where some areas are scoured of fine sediments while 
fine sediments are redeposited in other areas (Gordon et al. 1992, pp. 
304-305; Poff et al. 1997, pp. 771-772). This dynamic process is 
fundamental to maintaining habitat diversity in streams that ensure 
healthy ecosystem function (Lytle and Poff 2004, pp. 96-99; Poff et al. 
1997, pp. 774-777). Allowing natural stream flows, particularly during 
flood events, is an essential physical feature to maintain stream 
habitats for Devils River minnow.

Primary Constituent Elements for the Devils River Minnow

    Under the Act and its implementing regulations, we are required to 
identify the physical and biological features (PCEs) within the 
geographical area occupied by the species, which may require special 
management considerations or protections.
    Based on the above needs and our current knowledge of the life 
history, biology, and ecology of the species, we have determined that 
the Devils River minnow's PCEs are:
    1. Streams characterized by:
    a. Areas with slow to moderate water velocities between 10 and 40 
cm/second (4 and 16 in/second) in shallow to moderate water depths 
between approximately 10 cm (4 in) and 1.5 m (4.9 ft), near vegetative 
structure, such as emergent or submerged vegetation or stream bank 
riparian vegetation that overhangs into the water column;
    b. Gravel and cobble substrates ranging in size between 2 and 10 cm 
(0.8 and 4 in) with low or moderate amounts of fine sediment (less than 
65

[[Page 41685]]

percent stream bottom coverage) and low or moderate amounts of 
substrate embeddedness; and
    c. Pool, riffle, run, and backwater components free of artificial 
instream structures that would prevent movement of fish upstream or 
downstream.
    2. High-quality water provided by permanent, natural flows from 
groundwater spring and seeps characterized by:
    a. Temperature ranging between 17 [deg]C and 29 [deg]C (63 [deg]F 
and 84 [deg]F);
    b. Dissolved oxygen levels greater than 5.0 mg/l;
    c. Neutral pH ranging between 7.0 and 8.2;
    d. Conductivity less than 0.7 mS/cm and salinity less than 1 ppt;
    e. Ammonia levels less than 0.4 mg/l; and
    f. No or minimal pollutant levels for copper, arsenic, mercury, and 
cadmium; human and animal waste products; pesticides; fertilizers; 
suspended sediments; petroleum compounds and gasoline or diesel fuels.
    3. Abundant aquatic food base consisting of algae attached to 
stream substrates and other associated microorganisms.
    4. Aquatic stream habitat either devoid of nonnative aquatic 
species (including fish, plants, and invertebrates) or in which such 
nonnative aquatic species are at levels that allow for healthy 
populations of Devils River minnows.
    5. Areas within stream courses that may be periodically dewatered 
for short time periods, during seasonal droughts, but otherwise serve 
as connective corridors between occupied or seasonally occupied areas 
through which the species moves when the area is wetted.
    This proposed designation is designed for the conservation of PCEs 
necessary to support the life history functions that were the basis for 
the proposal and the areas containing those PCEs. Because not all life 
history functions require all the PCEs, not all proposed critical 
habitat will contain all the PCEs.

Special Management Considerations or Protections

    When designating critical habitat, we assess whether the occupied 
areas contain the features essential to the conservation of the species 
that may require special management considerations or protections. We 
provide a summary discussion below of the special management needs for 
the stream segments we have identified as occupied at the time of 
listing (Devils River and San Felipe Creek) and the area considered to 
be essential for the conservation of the Devils River minnow (Pinto 
Creek). For additional information regarding the threats to the Devils 
River minnow and the needed management strategies to address those 
threats, see the Devils River Minnow Recovery Plan (Service 2005, pp. 
1.7-1--1.7-7; 1.8-1--1.8-4; 2.5-1--2.5-5).
    The following special management needs apply to all three stream 
segments, Devils River, San Felipe Creek, and Pinto Creek, and will be 
further discussed for each stream segment in the Proposed Critical 
Habitat Designation below.
    a. Groundwater management. The waters that produce all three stream 
segments issue from springs that are supported by underground aquifers, 
generally some portion of the Edwards Trinity Aquifer (Ashworth and 
Stein 2005, pp.16-33; Barker and Ardis 1996, pp. B5-B6; Brune 1981, pp. 
274-277, 449-456; Green et al. 2006, pp. 28-29; LBG-Guyton Associates 
2001, pp. 5-6; PWPG 2006, pp. 3-5, 3-6, 3-30). Regional groundwater 
flow in this area is generally from north to south (Ashworth and Stein 
2005, Figure 8). This aquifer is currently pumped to provide water for 
human uses including agricultural, municipal, and industrial (Ashworth 
and Stein 2005, p.1; Green et al. 2006, pp. 28-29; LBG-Guyton 
Associates 2001, pp. 22-27; PWPG 2006, pp. 3-14, 3-15). Some parts of 
this aquifer have already experienced large water level declines due to 
a combination of pumping withdrawals and regional drought (Barker and 
Ardis 1996, p. B50). There are a number of preliminary project plans to 
significantly increase the amount of groundwater pumped in this area to 
export it to other metropolitan centers (HDR Engineering Inc. 2001, p. 
1-1; Khorzad 2002, p. 19; PWPG 2006, pp. 4-54). If the aquifers are 
pumped beyond their ability to sustain levels that support spring 
flows, these streams will no longer provide habitat for the Devils 
River minnow (Ashworth and Stein 2005, p.34; Edwards et al. 2004, p. 
256; Garrett et al. 2004, pp. 439-440). Flow reductions can have 
indirect effects on fishes by impacting thermal regimes because higher 
water flow buffers against temperature oscillations (Hubbs 1990, p. 
89).
    Groundwater pumping that could affect stream flows within the 
Devils River minnow's range is subject to limited management control. 
State agencies do not control groundwater. Groundwater resources in 
Texas are under the ``Rule of Capture,'' and groundwater use is not 
regulated by any State agency (Holladay 2006, p. 2; Potter 2004, p. 9). 
The rule of capture essentially provides that groundwater is a 
privately owned resource and, absent malice or willful waste, 
landowners have the right to take all the water they can capture under 
their land without liability to neighboring landowners, even if in so 
doing they deprive their neighbors of the water's use (Holladay 2006, 
p. 2; Potter 2004, p. 1).
    Local groundwater conservation districts are the method for 
groundwater management in Texas (Caroom and Maxwell 2004, pp. 41-42; 
Holladay 2006, p. 3). Most districts are created by action of the Texas 
Legislature (Lesikar et al. 2002, p. 13). The regulations adopted by 
local groundwater conservation districts vary across the State and 
often reflect local decisions based on regional preferences, geologic 
limitations, and the needs of citizens (Holladay 2006, p. 3). The 
Kinney County Groundwater Conservation District is a local authority 
with some regulatory control over the pumping and use of groundwater 
resources in Kinney County (Brock and Sanger 2003, p. 42-44). 
Currently, there is no groundwater district in Val Verde County. It is 
not known whether groundwater districts, such as the one in Kinney 
County, will limit groundwater use and exportation to allow for 
conservation of surface water flows for environmental needs (Brock and 
Sanger 2003, p. 42-44; Caroom and Maxwell 2004, p. 47-48; Marbury and 
Kelly 2005, p. 9). The regional water plan for this area recognizes 
that groundwater needs to be managed for the benefit of spring flows 
(PWPG 2006, p. 3-30) and that groundwater use should be limited so that 
``base flows of rivers and streams are not significantly affected 
beyond a level that would be anticipated due to naturally occurring 
conditions'' (Ashworth and Stein 2005, p. 34; PWPG 2006, p. 3-8). 
Special management efforts are needed across the range of the Devils 
River minnow to ensure that aquifers are used in a manner that will 
sustain spring flows and provide water as an essential physical feature 
for the species.
    b. Nonnative species. Controlling existing nonnative species and 
preventing the release of new nonnative species are special management 
actions needed across the range of the Devils River minnow. The best 
tool for preventing new releases is education of the public on the 
problems associated with nonnative species (Aquatic Nuisance Species 
Task Force 1994, pp. 16-17). Current nonnative species issues have been 
cited for possible impacts to the Devils River (smallmouth bass) and 
San Felipe Creek (armored

[[Page 41686]]

catfish) (Lopez-Fernandez and Winemiller 2005, p. 247; Thomas 2001, p. 
1; Robertson and Winemiller 2001, p. 220). The armored catfish may 
already be impacting Devils River minnows in San Felipe Creek through 
competition for common food resources of attached algae and associated 
microorganisms (Lopez-Fernandez and Winemiller 2005, p. 250). Hoover et 
al. (2004, pp. 6-7) suggest that nonnative catfishes in the family 
Loricaridae, like armored catfish, will impact stream systems and 
native fishes by competing for food with other herbivores, changing 
plant communities, bank erosion due to burrowing in stream banks for 
spawning, and incidentally ingesting fish eggs. Problem nonnative 
species have not been documented in Pinto Creek. Please see the above 
discussion in ``Habitat Protected From Disturbance or Representative of 
the Historic Geographical and Ecological Distribution of a Species'' 
for additional discussion of nonnative species.
    c. Pollution. Special management actions are needed to prevent 
point and nonpoint sources of pollution entering in the stream systems 
where the Devils River minnow occurs. Devils River and Pinto Creek are 
generally free of threats from obvious sources of pollution. San Felipe 
Creek is in an urban environment where threats from human-caused 
pollution are substantial. Potential for spill or discharge of toxic 
materials is an inherent threat in urban environments. In addition, 
there are little to few current controls in the City of Del Rio to 
minimize the pollutants that will run off into the creek during 
rainfall events from streets, parking lots, roof tops, and maintained 
lawns from private yards and the golf course (Winemiller 2003, p. 27). 
All of these surfaces will contribute pollutants (for example, 
fertilizers, pesticides, herbicides, petroleum products) to the creek 
and potentially impact biological functions of the Devils River minnow. 
In addition, trash is often dumped into or near the creek and can be a 
source of pollutants. Special management by the City of Del Rio is 
needed (City of Del Rio 2006, p. 13) to institute best management 
practices for controlling pollution sources that enter the creek and 
maintain the water quality at a level necessary to support Devils River 
minnow.
    d. Stream channel alterations. The stream channels in the three 
streams where Devils River minnow occurs should be maintained in 
natural conditions, free of instream obstructions to fish movement and 
with intact stream banks of native vegetation. Devils River and Pinto 
Creek are generally free of stream channel alterations; however, San 
Felipe Creek has been altered by diversion dams, bridges, and armoring 
of stream banks (replacing native vegetation and soils with rock or 
concrete). Special management is needed in all three occupied streams 
to protect the integrity of the stream channels for the conservation of 
Devils River minnow habitat.

Criteria Used To Identify Critical Habitat

    We are proposing to designate critical habitat for the Devils River 
minnow in areas that were occupied at the time of listing and contain 
sufficient PCEs to support life history functions essential for the 
conservation of the species, which may require special management 
considerations or protection. Critical habitat is also being proposed 
for areas not considered occupied at the time of listing, but 
subsequently discovered to be occupied and essential for the 
conservation of the Devils River minnow.
    Critical habitat is designated based on sufficient PCEs being 
present to support the life processes of the species. Some areas 
contain all PCEs and support multiple life processes. Some areas 
contain only a portion of the PCEs necessary to support the particular 
use of that habitat.
    a. Range. We evaluated the geographical range of the Devils River 
minnow, as described in the Recovery Plan (Service 2005, p. 
1.4.1.1.4.5). There are five stream segments in the United States (all 
in Texas) that have ever been known to have been occupied by the Devils 
River minnow: (1) The Devils River (Val Verde County) from Beaver Lake 
downstream to near the confluence with the Rio Grande; (2) San Felipe 
Creek (Val Verde County) from the headsprings on the Lowe Ranch to 
downstream of the City of Del Rio; (3) Sycamore Creek (Val Verde/Kinney 
county boundary), only documented from the Highway 277 Bridge crossing; 
(4) Pinto Creek (Kinney County) from Pinto Springs downstream to 0.5 
stream km (0.3 stream mi) upstream of the Highway 90 Bridge crossing; 
and (5) Las Moras Creek (Kinney County), only documented from the Las 
Moras Spring in the City of Brackettville.
    Each of these five stream segments has (or formerly had) isolated 
populations of Devils River minnow separated by long distances, 
unsuitable habitat, and/or large dams that prevent fish movements. 
Although each of these streams is a tributary to the Rio Grande, we do 
not expect any contemporary exchange of individuals between these 
stream segments. The Devils River minnow is generally associated with 
upstream reaches of these streams, and connectivity would require 
movement through downstream reaches, through the Rio Grande, and back 
upstream through uninhabited reaches. The Devils River minnow has not 
been documented in the Rio Grande, or any other of its tributaries in 
the United States in modern times (Contreras-Balderas et al. 2002, pp. 
228-240; Edwards et al. 2002, p. 123; Garrett et al. 1992, pp. 261-265; 
Hoagstrom 2003, p. 95; Hubbs 1957, p. 93; Hubbs 1990, p. 90; Hubbs et 
al. 1991, p. 18; Trevi[ntilde]o-Robinson 1959, p. 255). These stream 
reaches are considered unsuitable habitat (Garrett et al. 1992, p. 261) 
because the aquatic habitat is very different (larger volume, higher 
suspended sediments, different suite of native fishes) than the streams 
where the Devils River minnow is found. The presence of Amistad 
Reservoir and Dam has further isolated the Devils River stream segment 
from the other stream segments. While some exchange of individuals 
could have occurred across a geologic time scale, any natural exchange 
of individual Devils River minnows between currently occupied stream 
segments in modern times is unlikely because of habitat changes in the 
Rio Grande, nonnative species, and potential instream barriers.
    Lack of access to private property can limit opportunities to 
sample for the presence of Devils River minnow (such as occurred on 
Pinto Creek, see Garrett et al. (2004), p. 436) and may limit our 
ability to accurately determine the full range of the species. However, 
we do not expect any additional streams outside of the geographical 
range of the species to be occupied. There could be additional stream 
segments within the known range that may be found to be occupied during 
future surveys, but the best available information at this time 
supports only these five stream segments known to be or to have been 
occupied by Devils River minnow in the United States.
    b. Occupancy. For the purpose of this critical habitat designation, 
we consider a stream segment to be occupied if Devils River minnow has 
been found to be present by species experts within the last 10 years, 
or where the stream segment is directly connected to a segment with 
documented occupancy within the last 10 years (see Proposed Critical 
Habitat Designation for additional occupancy information). The life 
expectancy of Devils River minnow is assumed to be about 3 years, 
although individuals have lived 5 years in captivity (Gibson 2006, p. 
1). Ten years is estimated to represent a time period that provides for 
at least three

[[Page 41687]]

generations and should allow for an adequate time to detect occupancy. 
Most stream segments have not been surveyed with a high degree of 
frequency, and this species can be difficult to detect, as even 
multiple samples within a short time in the same location by the same 
researcher can yield different results (Garrett et al. 2002, p. 478). 
We have assessed the occupancy of stream segments based on the best 
survey information available.
    c. Areas occupied at the time of listing. At the time the Devils 
River minnow was listed as a threatened species, it was only confirmed 
to occur at two sites on the Devils River (small tributaries) and in 
San Felipe Creek in Del Rio, Texas (64 FR 56597). This species is 
reasonably expected to move throughout connected stream reaches, based 
on past and recent collection records from these streams (Garrett et 
al. 2002, p. 478). Therefore, we determine there are two stream 
segments that were occupied at the time of listing: (1) Devils River 
from Pecan Springs to downstream of Dolan Falls (Garrett 2006a, p. 4; 
Garrett 2007, p. 1); and (2) San Felipe Creek from the Head Spring to 
downstream through the City of Del Rio (Garrett 2006b, p. 1; Garrett 
2007, p.1). The full extent of both stream segments is considered 
occupied, as surveys in the last 10 years have confirmed the species 
presence in the streams and the unit consists of contiguous habitat 
that allows fish movement throughout the stream.
    d. Primary constituent elements. We are proposing to designate the 
stream segments that were occupied at the time of listing and contain 
sufficient PCEs to support life history functions essential for the 
conservation of the species. Both of the stream segments occupied at 
the time of listing (Devils River and San Felipe Creek) contain 
sufficient PCEs to support life history functions essential for the 
conservation of the Devils River minnow.
    e. Areas not occupied at time of listing. Section 3(5)(A)(ii) of 
the Act allows for critical habitat to be designated in areas outside 
the geographical area occupied by the species at the time it is listed 
if those areas are essential for the conservation of the species. Three 
stream segments historically occupied by Devils River minnow but not 
considered occupied at the time of listing include Sycamore Creek, 
Pinto Creek, and Las Moras Creek.
    Sycamore Creek and Las Moras Creek are not currently occupied by 
the Devils River minnow. The last known occurrence of the species in 
these stream segments was 1989 for Sycamore Creek (Garrett et al. 1992, 
p. 265) and 1955 for Las Moras Creek (Garrett et al. 1992, p. 266; 
Hubbs and Brown 1956, pp. 70-71). Although recent publications continue 
to list Sycamore Creek as a stream where Devils River minnow may still 
occur (Garrett et al. 2004, p. 435; Lopez-Fernandez and Winemiller, p. 
247), we have a high degree of uncertainty as to the status of the fish 
in Sycamore Creek. Collections in 1999 and 2002 from the area of last 
known occurrence (in 1989) did not yield Devils River minnow (G. 
Garrett, TPWD, unpublished data 2002). In addition, Garrett et al. 
(1992) surveyed portions of Mud Creek (a tributary to Sycamore Creek) 
in 1989 but found no Devils River minnow. Additional surveys are needed 
to determine the current status of the fish in the Sycamore Creek 
watershed. Devils River minnow has not been collected from Las Moras 
Creek since the 1950s and is believed to be extirpated from the Las 
Moras Creek drainage. This conclusion is based on the absence of the 
species in sampling efforts from the late 1970s to 2002 (Smith and 
Miller 1986; Hubbs et al. 1991; Garrett et al. 1992; G. Garrett, 
unpublished data 2002).
    Restoring Devils River minnow to Sycamore Creek and Las Moras Creek 
may be important to achieve recovery goals for the species and optimize 
the chances of long-term species conservation (Service 2005, pp. 2.1-
1--2.2-3). Recovery criteria for Devils River minnow include having 
stable or increasing populations in both Sycamore Creek and Las Moras 
Creek, if reestablishment in Las Moras Creek is scientifically 
feasible. However, the feasibility of restoring populations in these 
areas is uncertain and the recovery plan advises additional assessment 
and landowner willingness will be necessary in both areas before 
restoration could occur. Therefore, based on the lack of information 
regarding the species status in Sycamore Creek, uncertainty of the 
potential for restoration in either stream segment, and the absence of 
data to demonstrate that the streams possess the PCEs, for the purposes 
of critical habitat designation, we have not included Sycamore Creek 
and Las Moras Creek in the proposed critical habitat designation.
    Due to the importance of these stream segments to the recovery of 
Devils River minnow, we solicit additional information and comments 
from interested parties on the distribution of Devils River minnow, 
specifically in the Sycamore Creek and Las Moras Creek watersheds. 
Information received, as well as supporting documentation will be used 
in the consideration of Sycamore Creek and Las Moras Creek's inclusion 
in the final critical habitat designation. We may consider including 
Sycamore Creek and Las Moras Creek in our critical habitat designation 
if we receive additional information during the public comment period 
that leads to a determination that these stream segments are essential 
to the conservation of Devils River minnow.
    At the time of listing in 1999, previous fish surveys in Pinto 
Creek were limited to the locations of public access at highway bridge 
crossings and did not find the species present (Garrett et al. 1992, p. 
260). In 2001, fish surveys in upstream areas of Pinto Creek discovered 
the previously unknown population of Devils River minnow (Garrett et 
al. 2004, p. 436-439). The species has been confirmed to occur from 
just upstream of the Highway 90 Bridge crossing upstream to the origin 
of Pinto Creek at Pinto Springs (Garrett et al. 2004, p. 438-439). 
Since this stream segment is isolated from other occupied areas, this 
stream segment was likely occupied at the time of listing, but 
appropriate surveys had not been conducted to verify it. We find that 
the Pinto Creek stream segment is essential to the conservation of the 
Devils River minnow because preliminary analysis have shown significant 
genetic variation between Devils River minnow populations in Pinto 
Creek and the Devils River (Service 2006, p. 15). Also Pinto Creek 
provides the best source of Devils River minnows (due to proximity and 
habitat similarity) to implement possible future recovery actions if 
reestablishing the species into nearby Las Moras Creek proves feasible 
(Garrett et al. 2004, p. 440).
    f. Lateral Extent. The areas designated as critical habitat are 
designed to provide sufficient areas for breeding, non-breeding adults 
and rearing of juvenile Devils River minnow. In general, the PCEs of 
critical habitat for Devils River minnow include the spring heads and 
the wetted channel during average flow conditions of the stream 
segments. The Devils River minnow evolved in streams maintained by 
consistent flows from groundwater springs that varied little 
seasonally. Episodic floods, sometimes very large floods, are important 
for maintenance of the natural stream channel and fish communities 
(Harrell 1978, p. 67; Valdes Cantu and Winemiller 1997, pp. 276-277); 
however, the streams do not have a regular seasonal pattern of 
flooding. As a result, the life history of the Devils River minnow is 
not dependent on high flow events and the inundation of overbank areas. 
Therefore, the floodplain is not known to contain

[[Page 41688]]

the features essential for the species' conservation and is not 
included in the proposed critical habitat designation.
    We propose that this critical habitat designation include a lateral 
extent that is limited to the normal wetted channel of the streams 
proposed for inclusion. For the purposes of this proposal, the wetted 
channel is considered the width of the stream channel at bankfull 
stage. Bankfull stage is the height when stream flows just fill the 
stream to its banks before water spills out onto the adjacent 
floodplain (Gordon et al. 1992, pp. 305-307). The stream discharge that 
reaches bankfull stage occurs 1 or 2 days each year and has a 
recurrence interval that averages 1.5 years (Leopold 1994, pp. 129-
141). This lateral extent will encompass the immediate streamside 
vegetation that can extend into the water column and provide vegetative 
structure, one of the PCEs.
    Summary. We are proposing to designate critical habitat in areas 
that we have determined were occupied at the time of listing, and that 
contain sufficient PCEs to support life history functions essential for 
the conservation of the species. Stream segments are proposed for 
designation based on sufficient PCEs being present to support the life 
processes of the species. Some stream segments contain all PCEs and 
support multiple life processes. Some stream segments contain only a 
portion of the PCEs necessary to support the particular use of that 
habitat. For stream segments that were not occupied at the time of 
listing, we evaluated whether those areas were essential to the 
conservation of the Devils River minnow.
    We find that two stream segments were occupied at the time of 
listing and contain sufficient PCEs to support life history functions 
essential for the conservation of the species: (1) Devils River from 
Pecan Springs to downstream of Dolan Falls, including short stretches 
of two tributaries, Phillips Creek and Dolan Creek, and (2) San Felipe 
Creek from the headsprings downstream through the City of Del Rio, 
include the outflow channels of East and West Sandia springs. We find 
that a third stream segment, Pinto Creek from Pinto Springs downstream 
to the Highway 90 Bridge crossing, was not known to be occupied at the 
time of listing, but was subsequently discovered to be occupied and is 
now considered to be essential for the conservation of the Devils River 
minnow for the reasons discussed above.
    Within this proposed rule, the critical habitat boundary is limited 
to bankfull width of the stream segments proposed for inclusion, at the 
height in which stream flows just fill the stream to its banks before 
water spills out onto the adjacent floodplain. The scale of the 
critical habitat maps prepared under the parameters for publication 
within the Code of Federal Regulations may not reflect the exclusion of 
developed areas such as buildings, paved areas, and other structures 
that lack PCEs for the Devils River minnow. Any such structures and the 
land under them inside critical habitat boundaries shown on the maps of 
this proposed rule are not proposed for designation as critical 
habitat. Therefore, Federal actions limited to these areas would not 
trigger section 7 consultation, unless they affect the species or PCEs 
in adjacent critical habitat.

Proposed Critical Habitat Designation

    We are proposing three units as critical habitat for the Devils 
River minnow. The three units are: (1) Devils River Unit; (2) San 
Felipe Creek Unit; and (3) Pinto Creek Unit. All three areas are 
currently occupied by the Devils River minnow and constitute our best 
assessment of areas that meet the definition of critical habitat for 
the species.
    The proposed critical habitat areas include the stream channels up 
to bankfull width within the identified stream reaches. The stream beds 
of perennial streams and navigable waters (stream beds of at least 30 
ft wide) in Texas are generally owned by the State, in trust for the 
public, while the lands alongside the streams can be privately owned 
(Riddell 1997, p. 7). We presume that the stream beds for all three 
stream segments being proposed for critical habitat are considered 
public.
    All distances reported in this proposal are estimated stream 
lengths calculated using geographic information system computer 
software (ArcGIS) approximating the stream channel (reported in stream 
km and stream mi). Stream channel lines were based on the National 
Hydrography Dataset and 7.5' topographic quadrangle maps obtained from 
the U.S. Geological Survey. We made some minor adjustments using the 
2004 National Agriculture Imagery Program digital orthophotos obtained 
from the Texas Natural Resources Information System. The approximate 
length of each stream segment for each proposed critical habitat unit 
is shown in Table 1.

  Table 1.--Proposed Critical Habitat Units for the Devils River Minnow
------------------------------------------------------------------------
                                                           Total stream
                 Critical habitat unit *                    km  (stream
                                                                mi)
------------------------------------------------------------------------
1. Devils River Unit (includes Philips and Dolan creeks)     47.0 (29.2)
2. San Felipe Creek Unit (includes outflow of East and         9.0 (5.6)
 West springs)..........................................
3. Pinto Creek Unit.....................................     17.5 (10.9)
                                                         ---------------
  Total.................................................     73.5 (45.7)
------------------------------------------------------------------------
* The stream beds of all three units being proposed for critical habitat
  are considered public, and owned by the state of Texas.

    The proposed critical habitat designation for Devils River minnow 
includes a total of 73.5 stream km (45.7 stream mi). Below, we provide 
brief descriptions of the three units, and reasons why each meets the 
definition of critical habitat for the Devils River minnow.

Unit 1: Devils River Unit

    Proposed Unit 1 consists of approximately 43.6 stream km (27.1 
stream mi) of the Devils River; 1.1 stream km (0.7 stream mi) of 
Phillips Creek; and 2.3 stream km (1.4 stream mi) of Dolan Creek. 
Phillips Creek and Dolan Creek are small tributaries to the Devils 
River that contain PCEs and are occupied by the Devils River minnow. 
The proposed upstream boundary on the Devils River is at Pecan Springs. 
The proposed downstream boundary on the Devils River is 3.6 stream km 
(2.2 stream mi) below Dolan Falls. Phillips Creek is included from the 
confluence with the Devils River to a point 1.1 stream km (0.7 stream 
mi) upstream. Dolan Creek is included from the confluence with the 
Devils River 2.3 stream km (1.4 stream mi) upstream to Dolan Springs. 
Including all three streams, the total distance in the proposed 
critical habitat in the Devils River Unit is approximately 47.0 stream 
km (29.2 stream mi). For specific coordinates of the boundaries for 
proposed critical habitat designation, please reference the unit 
descriptions in the Proposed Regulation Promulgation section below.
    The Devils River minnow was originally described from this unit in 
the 1950s (Hubbs and Brown 1956, p. 70) and it has been continually 
occupied ever since (Harrell 1978, pp. 64, 67; Garrett et al. 1992, p. 
261, Service 2005, Appendix A). The Devils River minnow occupied this 
unit at the time of listing, though at only a few locations. Subsequent 
surveys by TPWD

[[Page 41689]]

have established current occupancy of this entire unit (Service 2005, 
Appendix A). The proposed upstream boundary of critical habitat 
represents the beginning of the permanent flow of the river (De La Cruz 
2004, p. 1). The proposed downstream boundary, 3.6 stream km (2.2 
stream mi) downstream of Dolan Falls, represents the downstream extent 
of collections of the Devils River minnow by TPWD (Garrett 2007, p. 1).
    The Devils River Unit contains one or more of the PCEs essential 
for conservation of the Devils River minnow. Special management in the 
Devils River Unit may be needed to control groundwater pumping to 
ensure spring flows are maintained and to prevent the introduction of 
nonnative species. See additional discussion above in the Special 
Management Considerations or Protections section.
    Areas proposed as critical habitat for Devils River minnow do not 
include lands adjacent to the stream channels. However, land ownership 
adjacent to the streams in the Devils River Unit is primarily private. 
Private ownership of the area includes The Nature Conservancy's 1,943-
ha (4,800-ac) Dolan Falls Preserve, which also includes river frontage 
on the Devils River and Dolan Creek. The Nature Conservancy has owned 
this area since 1991 (The Nature Conservancy 2004, 9). The Nature 
Conservancy also holds conservation easements on about 66,800 ha (about 
165,000 ac) of private land along the Devils River or in the Devils 
River watershed (McWilliams 2006, p. 1). The only public land adjacent 
to the streams of this unit is the State-owned Devils River State 
Natural Area (DRSNA) managed by the TPWD. Proposed critical habitat 
within the DRSNA includes about 1.6 stream km (1.0 stream mi) along the 
east bank of the Devils River and about 1.9 stream km (1.17 stream mi) 
along both banks of a portion of Dolan Creek. Yet, these adjacent 
public lands are not included in the proposed critical habitat 
designation.

Unit 2: San Felipe Creek Unit

    Proposed Unit 2 consists of approximately 7.9 stream km (4.9 stream 
mi) on San Felipe Creek; 0.8 stream km (0.5 stream mi) of the outflow 
of San Felipe Springs West; and 0.3 stream km (0.2 stream mi) of the 
outflow of San Felipe Springs East. The proposed upstream boundary on 
San Felipe Creek is the Head Springs located about 1.1 stream km (0.7 
stream mi) upstream of the Jap Lowe Bridge crossing. The proposed 
downstream boundary on San Felipe Creek is in the City of Del Rio 0.8 
stream km (0.5 stream mi) downstream of the Academy Street Bridge 
crossing. The proposed unit includes the outflow channels of two 
springs San Felipe Springs West and San Felipe Springs East. These 
channels are included in the proposed critical habitat from their 
spring origin downstream to the confluence with San Felipe Creek. 
Including all three streams, the total distance in the proposed 
critical habitat in the San Felipe Creek Unit is approximately 9.0 
stream km (5.6 stream mi). For specific coordinates of the boundaries 
for proposed critical habitat designation, please reference the unit 
descriptions in the Proposed Regulation Promulgation section below.
    San Felipe Creek was occupied by the Devils River minnow at the 
time of listing and is still occupied (Hubbs and Brown 1956, p. 70; 
Garrett et al. 1992, pp. 261, 265; Service 2005, Appendix A; Lopez-
Fernandez and Winemiller 2005, p. 249). Although limited survey data is 
available, we consider the entire unit occupied as the habitat is 
contiguous, allowing fish to move throughout the unit (Garrett 2006b, 
p. 1). The proposed boundaries of critical habitat include all areas 
where TPWD has collected Devils River minnow within the San Felipe 
Creek Unit (Garrett 2007, p. 1).
    The San Felipe Creek Unit contains one or more of the PCEs 
essential for conservation of the Devils River minnow. There are 
several unnatural barriers to fish movement that may currently segment 
the reaches within the City of Del Rio. Portions of the stream banks in 
the City have been significantly altered by arming with concrete and 
the invasion of an exotic cane (Arundo donax). However, much of the 
riparian area remains a functional part of the stream ecosystem, 
contributing to the physical and biological features of Devils River 
minnow habitat. Water quality in San Felipe Creek has been a concern 
due to the urban environment through which much of the creek flows. 
Potential for spill or discharge of toxic materials is an inherent 
threat in urban environments (City of Del Rio 2006, p. 13). The threats 
to the San Felipe Creek Unit that require special management include 
the potential for large-scale groundwater withdrawal and exportation 
that would impact spring flows, pollution from urban runoff, nonnative 
vegetation on stream banks, other nonnative species (such as the 
armored catfish), and potential new nonnative species introductions 
into the stream.
    Land ownership adjacent to the streams banks being proposed as 
critical habitat within the San Felipe Creek Unit includes private 
ranch lands from the Head Springs downstream to the City of Del Rio. 
Within the city limits, the City owns various tracts of land along the 
stream. Some of these areas are developed as public use parks and 
others have been recently obtained through a buyout program from the 
Federal Emergency Management Agency following damages from the 1998 
flood (City of Del Rio 2006, pp. 5-6). Most of the City-owned property 
along the river appears to be on the east bank of the creek, while the 
west bank is primarily private-owned residences. The San Felipe Springs 
East and West and their immediate outflow channels are on a golf 
course, privately owned by the San Felipe Country Club. In all, we 
estimate that the City of Del Rio owns about 1.1 stream km (0.7 stream 
mi) along both banks of the creek and spring outflow channels, mainly 
located downstream of the Highway 90 Bridge. Through the remainder of 
the City, we estimated the City owns about 2.2 stream km (1.4 stream 
mi) along the east bank of San Felipe Creek in parcels fragmented by 
private holdings. These private and city-owned lands are not included 
in the proposed critical habitat designation.

Unit 3: Pinto Creek Unit

    Proposed Unit 3 consists of approximately 17.5 stream km (10.9 
stream mi) on Pinto Creek. The proposed upstream boundary is Pinto 
Springs. The proposed downstream boundary is 100 m (330 ft) upstream of 
the Highway 90 Bridge crossing of Pinto Creek. For specific coordinates 
of the boundaries for proposed critical habitat designation, please 
reference the unit descriptions in the Proposed Regulation Promulgation 
section below.
    Pinto Creek was not considered occupied by Devils River minnow at 
the time of listing; however, Devils River minnows were documented in 
2001 in upstream reaches of the creek where fish surveys had not been 
previously conducted (Garrett et al. 2004, p. 437). The Pinto Creek 
Unit is essential for the conservation of the Devils River minnow 
because fish from this stream show significant genetic variation from 
other populations (Service 2006, p. 15). Because of it's proximity to 
Las Moras Creek and the genetic variation from the more western 
population, fish from Pinto Creek would be the likely source population 
for possible future reintroduction into formerly occupied areas 
(Garrett et al. 2004, p. 440). The proposed boundaries of critical 
habitat represent all the areas within Pinto Creek where Devils River 
minnow has been collected (Garrett et al. 2004, p. 437-438).

[[Page 41690]]

    Further, the Pinto Creek Unit contains one or more of the PCEs 
essential for conservation of the Devils River minnow. The main threat 
to the Pinto Creek Unit that requires special management is the 
potential for large-scale groundwater withdrawal and exportation that 
would significantly impact spring flows. While nonnative species are 
not currently known to be a problem in Pinto Creek, preventing 
nonnative species from being introduced into the stream is an 
additional threat needing special management. Land ownership adjacent 
to the Pinto Creek unit is all private ranches; however, these private 
lands are not included in the proposed critical habitat designation.

Effects of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including the 
Service, to ensure that actions they fund, authorize, or carry out are 
not likely to destroy or adversely modify critical habitat. Decisions 
by the 5th and 9th Circuit Court of Appeals have invalidated our 
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, 442F (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 current 
national policy and the statutory provisions of the Act, we determine 
destruction or adverse modification is determined on the basis of 
whether, with implementation of the proposed Federal action, the 
affected critical habitat would remain functional (or retain the 
current ability for the PCEs to be functionally established) to serve 
its intended conservation role for the species.
    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. This is a procedural 
requirement only, as any conservation recommendations in a conference 
report or opinion are strictly advisory. However, once a species 
proposed for listing becomes listed, or proposed critical habitat is 
designated as final, the full prohibitions of section 7(a)(2) apply to 
any discretionary Federal action.
    The primary utility of the conference procedures is to allow a 
Federal agency to maximize its opportunity to adequately consider 
species proposed for listing and proposed critical habitat and to avoid 
potential delays in implementing their proposed action because of the 
section 7(a)(2) compliance process, should we list those species or 
designate critical habitat. We may conduct conferences either 
informally or formally. We typically use informal conferences as a 
means of providing advisory conservation recommendations to assist the 
agency in eliminating conflicts that the proposed action may cause. We 
typically use formal conferences when we or the Federal agency believes 
the proposed action is likely to jeopardize the continued existence of 
the species proposed for listing or adversely modify proposed critical 
habitat.
    We generally provide the results of an informal conference in a 
conference report, while we provide the results of a formal conference 
in a conference opinion. We typically prepare conference opinions on 
proposed species or critical habitat in accordance with procedures 
contained at 50 CFR 402.14, as if the proposed species were already 
listed or the proposed critical habitat was already designated. We may 
adopt the conference opinion as the biological opinion when the species 
is listed or the critical habitat is designated, if no substantial new 
information or changes in the action alter the content of the opinion 
(see 50 CFR 402.10(d)).
    If a species is listed or critical habitat is designated, 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 to destroy or adversely modify 
its critical habitat. 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. As a result of this 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, and 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 or 
destroy or adversely modify critical habitat, we also provide 
reasonable and prudent alternatives to the project, if any are 
identifiable. ``Reasonable and prudent alternatives'' are defined at 50 
CFR 402.02 as alternative actions identified during consultation that 
can be implemented in a manner consistent with the intended purpose of 
the action, that can be implemented consistent with the scope of the 
Federal agency's legal authority and jurisdiction, that are 
economically and technologically feasible, and that would, in the 
Director's opinion, avoid jeopardizing the continued existence of the 
listed species or 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 
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, some 
Federal agencies may request reinitiation of consultation with us on 
actions for which formal consultation has been completed, if those 
actions may affect subsequently listed species or designated critical 
habitat.
    Federal activities that may affect the Devils River minnow or its 
designated critical habitat will require section 7 consultation under 
the Act. Activities on State, Tribal, local, or private lands requiring 
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 under section 10(a)(1)(B) of the Act from the 
Service) or involving some other Federal action (such as funding from 
the Federal Highway Administration, Federal Aviation Administration, or 
the Federal Emergency Management Agency) are also subject to the 
section 7 consultation process. Federal actions not affecting listed 
species or critical habitat, and actions on State, Tribal, local or 
private lands that are not federally funded, authorized, or permitted, 
do not require section 7 consultations.
    There are no Federal lands in the areas being proposed for critical 
habitat for Devils River minnow. Laughlin Air Force Base is located 
east of the City of Del Rio and obtains its municipal water from the 
City (which ultimately is withdrawn from the two San Felipe Springs). 
The Amistad National

[[Page 41691]]

Recreation Area, located around Amistad Reservoir, is owned by the 
National Park Service and includes the downstream portions of the 
Devils River, but is not included in the proposed critical habitat 
designation.
    Since the Devils River minnow was listed in 1999, two section 7 
consultations have occurred, both of which were associated with San 
Felipe Creek. One informal consultation was completed in 2001 with the 
Environmental Protection Agency for funding through the Texas Water 
Development Board to the City of Del Rio to upgrade the City's water 
treatment and distribution facilities. The other (formal) consultation 
was completed in 2006 with the Federal Highway Administration, through 
the Texas Department of Transportation, to replace the Beddell Avenue 
Bridge over San Felipe Creek. Based on this consultation history, we 
anticipate few future Federal actions within the area proposed for 
critical habitat for Devils River minnow.

Application of the ``Adverse Modification'' Standard for Actions 
Involving Effects to the Critical Habitat of the Devils River Minnow

    For the reasons described in the Director's December 9, 2004 
memorandum, 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, or would retain its current 
ability for the PCEs to be functionally established. Activities that 
may destroy or adversely modify critical habitat are those that alter 
the PCEs to an extent that appreciably reduces the conservation value 
of critical habitat for the Devils River minnow is appreciably reduced.
    Section 4(b)(8) of the Act requires us to briefly evaluate and 
describe, in any proposed or final regulation that designates critical 
habitat, those activities involving a Federal action that may destroy 
or adversely modify such habitat, or that may be affected by such 
designation.
    Activities that, when carried out, funded, or authorized by a 
Federal agency, may affect critical habitat and therefore would result 
in consultation for the Devils River minnow include, but are not 
limited to: 6
    (1) Actions that would alter the natural flow regime, particularly 
the reduction of spring flows. These activities could include, but are 
not limited to, excessive groundwater pumping (significantly greater 
than current levels), water diversions from streams, and stream 
impoundments. These activities could reduce the amount of available 
habitat and space for normal behaviors of Devils River minnow, alter 
water quality as an indirect effect of reduced flows, alter the 
mesohabitat (pools, riffles, and runs) conditions necessary for Devils 
River minnow life history functions, and alter fish community dynamics 
to unnaturally favor species other than the Devils River minnow.
    (2) Actions that would reduce native aquatic vegetation or native 
vegetation along stream banks. These activities could include, but are 
not limited to, channelization of the stream, armoring stream banks 
(replacing native vegetation and soils with rock or concrete), dredging 
the stream bottom, introducing nonnative plants that would replace 
native vegetation, or introducing herbivorous nonnative species. Loss 
of aquatic vegetation would eliminate an important structural component 
of Devils River minnow habitat and could reduce the amount of available 
habitat for reproduction, growth, and feeding.
    (3) Actions that would significantly alter water quality or 
introduce pollutants into streams. Such activities could include, but 
are not limited to, release of chemicals, biological pollutants, or 
heated effluents (liquid waste products) into the surface water or 
connected groundwater at a point source or by dispersed release (non-
point source). Sources of pollutants also include, but are not limited 
to, storm water runoff from urban development without adequate storm 
water controls; spill of hazardous chemicals into the creek or 
groundwater; or groundwater contamination by improperly drilled or 
maintained oil or gas wells. These activities could alter water 
conditions that are beyond the tolerances of the Devils River minnow or 
their food source and could result in direct or cumulative adverse 
effects to these individuals and their life cycles.
    (4) Actions that would significantly increase sediment deposition 
within the stream channel. Such activities could include, but are not 
limited to, excessive sedimentation from livestock grazing, road 
construction, channel alteration, brush clearing, off-road vehicle use, 
and other watershed and floodplain disturbances. These activities could 
eliminate or reduce the habitat necessary for the reproduction of 
Devils River minnow and could reduce the availability of food sources 
by affecting light penetration into the water column, filling in of 
stream beds with silt, or increasing the embeddedness of stream bottoms 
that reduces algae availability.
    (5) Actions that would significantly alter channel shape or 
geometry. Such activities could include, but are not limited to, 
channelization, impoundment, armoring stream banks, road and bridge 
construction, mining, dredging, and destruction of riparian vegetation. 
These activities may alter the natural pattern of available 
mesohabitats (pools, riffles, and runs). These actions can reduce the 
amount of habitat available for Devils River minnow to complete its 
normal life cycle and can give other species, especially nonnative 
species, competitive advantages. These actions can also lead to 
increased sedimentation and degradation in water quality to levels that 
are beyond the tolerances of the fish or their food sources.

Exclusions

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

    Section 4(b)(2) of the Act states that critical habitat shall be 
designated, and revised, 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 Congressional record is clear that the Secretary is 
afforded broad discretion regarding which factor(s) to use and how much 
weight to give to any factor.
    Under section 4(b)(2) of the Act, in considering whether to exclude 
a particular area from the designation, we must identify the benefits 
of including the area in the designation, identify the benefits of 
excluding the area from the designation, and then determine whether the 
benefits of exclusion outweigh the benefits of inclusion. If an 
exclusion is contemplated, then we must determine whether excluding the 
area would result in the extinction of the species. In the following 
sections, we address a number of general issues that are relevant to 
the exclusions we considered. In addition, the Service is conducting an 
economic analysis of the impacts of the proposed critical habitat 
designation and related factors, which will be available for public 
review and comment when it is complete. Based on public comment on that 
document, the

[[Page 41692]]

proposed designation itself, and the information in the final economic 
analysis, additional areas beyond those identified in this assessment 
may be excluded from critical habitat by the Secretary under the 
provisions of section 4(b)(2) of the Act. This is provided for in the 
Act and in our implementing regulations at 50 CFR 424.19.
    Under section 4(b)(2) of the Act, we must consider all relevant 
impacts, including economic ones. The Service considers a number of 
factors in its section 4(b)(2) analysis. For example, the Service 
considers whether there are lands owned or managed by the Department of 
Defense (DOD) where there might be a national security impact. We also 
consider whether the landowners have developed any conservation plans 
for the area, or whether there are conservation partnerships that would 
be encouraged by an area being designated as, or excluded from critical 
habitat. We look at any Tribal issues, and consider the government-to-
government relationship of the United States with Tribal entities. We 
also consider any social or economic impacts that might occur because 
of the designation. In this instance, we have determined that the lands 
within the proposed designation of critical habitat for Devils River 
minnow are not owned or managed by the Department of Defense, and the 
proposed designation does not include any Tribal lands or trust 
resources.
    At this time, we are not proposing any areas for exclusion from the 
final critical habitat designation under section 4(b)(2) of the Act; 
however, there are several ongoing conservation efforts related to 
habitat maintenance for the Devils River minnow (for example, see 
Garrett 2003, pp. 155-158; Karges 2003, pp. 147-148). Discussed below 
are conservation efforts and management plans that we may consider in 
our analysis of the benefits of inclusion and benefits of exclusion for 
certain proposed units from the final designation of critical habitat.

Ongoing Conservation Efforts for Consideration Under Section 4(b)(2) of 
the Act

    (1) Conservation Area Plan and Conservation Easements by The Nature 
Conservancy in the Devils River watershed. The Nature Conservancy has a 
very active conservation program in the Devils River watershed (Karges 
2003, pp. 147-148). The Nature Conservancy has developed a Conservation 
Area Plan for the Devils River with goals of the plan including 
balancing the relative abundance of native and nonnative fish species 
and maintaining or enhancing the condition and beauty of riparian 
gallery woodlands (The Nature Conservancy 2004, p. 6). Rivers, streams, 
and springs are recognized as viable conservation elements whose 
function can likely be sustained within natural variations, as long as 
large-scale groundwater mining does not occur (The Nature Conservancy 
2004, pp. 18-19). The Nature Conservancy owns about 1,943 ha (4,800 ac) 
and holds conservation easements on about 66,800 ha (about 165,000 ac) 
of private land in the Devils River watershed (McWilliams 2006, p. 1).
    (2) Management plans by the City of Del Rio and the San Felipe 
Creek Country Club. In 2003, the City of Del Rio and the San Felipe 
Creek Country Club each signed management plans for the protection of 
San Felipe Creek (Service 2005, Appendix C). The mission of the City's 
plan is to ``preserve and conserve the natural and cultural resources 
of the San Felipe Creek for the use and enjoyment of the present and 
future generations of Del Rio citizens and visitors.'' Proposed actions 
include: converting lands obtained along the creek following the 1998 
flood into passive parks; minimizing use of pesticides and fertilizers 
on City-owned lands along the creek; discouraging commercial 
development along the creek; preserving the natural water flow to the 
greatest extent possible; preserving stream banks in a natural state 
with buffer zones of native vegetation; public education; litter 
removal; and removal of nonnative plants, such as the river cane. The 
City has recently drafted a San Felipe Creek Master Plan (City of Del 
Rio, 2006, p.1) and intends to complete development of the plan in 
2007.
    The Management Plan for San Felipe Country Club in Del Rio included 
objectives ``to use environmentally sensitive techniques for managing 
and maintaining a high quality golf course for the benefit of users 
while also promoting natural diversity, and to protect and enhance the 
quality of San Felipe Creek and San Felipe Springs for the benefit of 
the Devils River minnow and the entire creek and riparian ecosystem.'' 
Management actions included establishing no-mow buffer zones, using 
environmentally sensitive pest management solutions through an 
Integrated Pest Management Program, using fertilizers judiciously; 
removing noxious vegetation, maintaining out of play areas as native 
habitat, using irrigation water wisely, and retaining runoff from 
parking lots.
    (3) Kinney County Groundwater Conservation District. The Kinney 
County Groundwater Conservation District exists for the management of 
groundwater resources in Kinney County. This District passed its 
initial rules in 2002 (and modified them in 2003) and is continuing to 
support groundwater research to determine aquifer boundaries and 
groundwater availability in Kinney County.
    (4) Watershed management planning. TPWD has initiated development 
of a stakeholder-lead watershed management plan for the range of the 
Devils River minnow in Val Verde and Kinney Counties. The intent of the 
plan is to protect, enhance, or restore essential habitat throughout 
the range of the federally threatened Devils River minnow and other 
species of concern in this area, and will define actions that will 
result in maintaining or increasing populations of these fishes. The 
plan has not yet been completed.

Economics

    An analysis of the economic impacts of proposing critical habitat 
for the Devils River minnow is being prepared. 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.fws.gov/southwest/es/Library/, or by 
contacting the Austin Ecological Services Field Office directly (see 
ADDRESSES).

Peer Review

    In accordance with our joint policy 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 such review is to ensure 
that our critical habitat designation is based on scientifically sound 
data, assumptions, and analyses. We will send copies of this proposed 
rule to these peer reviewers immediately following publication in the 
Federal Register. We will invite these peer reviewers to comment during 
the public comment period on the specific assumptions and conclusions 
regarding the proposed designation of critical habitat.
    We will consider all comments and information received during the 
comment period on this proposed rule during preparation of a final 
rulemaking determination. Accordingly, the final decision may differ 
from this proposal.

[[Page 41693]]

Public Hearings

    The Act provides for one or more public hearings on this proposal, 
if requested. Under section 4(b)(5)(e) of the Act, requests for public 
hearings must be made in writing at least 45 days following the 
publication of the proposed rule. We will schedule public hearings on 
this proposal, if any are requested, and announce the dates, times, and 
places of those hearings in the Federal Register and local newspapers 
at least 15 days prior to the first hearing.
    Persons needing reasonable accommodations to attend and participate 
in the public hearings should contact Adam Zerrenner, Field Supervisor, 
Austin Ecological Services Field Office at (512) 490-0057 as soon as 
possible. To allow sufficient time to process requests, please call no 
later than one week before the hearing date. Information regarding the 
proposal is available in alternative formats upon request.

Clarity of the Rule

    Executive Order 12866 (Regulatory Planning and Review) requires 
each agency to write regulations and notices that are easy to 
understand. We invite your comments on how to make this proposed rule 
easier to understand, including answers to questions such as the 
following: (1) Are the requirements in the proposed rule clearly 
stated? (2) Does the proposed rule contain technical jargon that 
interferes with the clarity? (3) Does the format of the proposed rule 
(grouping and order of the sections, use of headings, paragraphing, and 
so forth) aid or reduce its clarity? (4) Is the description of the 
notice in the SUPPLEMENTARY INFORMATION section of the preamble helpful 
in understanding the proposed rule? (5) What else could we do to make 
this proposed rule easier to understand?
    Send a copy of any comments on how we could make this proposed rule 
easier to understand to: Office of Regulatory Affairs, Department of 
the Interior, Room 7229, 1849 C Street, NW., Washington, DC 20240. You 
may e-mail your comments to this address: [email protected].

Required Determinations

Regulatory Planning and Review

    In accordance with Executive Order 12866, this document is a 
significant rule in that it may raise novel legal and policy issues, 
but it is not anticipated to have an annual effect on the economy of 
$100 million or more or affect the economy in a material way. Due to 
the tight timeline for publication in the Federal Register, the Office 
of Management and Budget (OMB) has not formally reviewed this rule. We 
are preparing a draft economic analysis of this proposed action, which 
will be available for public comment, to determine the economic 
consequences of designating the specific area as critical habitat. This 
economic analysis also will be used to determine compliance with 
Executive Order 12866, Regulatory Flexibility Act, Small Business 
Regulatory Enforcement Fairness Act, Executive Order 12630, Executive 
Order 13211, and Executive Order 12875.
    Further, Executive Order 12866 directs Federal Agencies 
promulgating regulations to evaluate regulatory alternatives (Office of 
Management and Budget, Circular A-4, September 17, 2003). Pursuant to 
Circular A-4, once it has been determined that the Federal regulatory 
action is appropriate, then the agency will need to consider 
alternative regulatory approaches. Since the determination of critical 
habitat is a statutory requirement under the Act, we must then evaluate 
alternative regulatory approaches, where feasible, when promulgating a 
designation of critical habitat.
    In developing our designations of critical habitat, we consider 
economic impacts, impacts to national security, and other relevant 
impacts under section 4(b)(2) of the Act. Based on the discretion 
allowable under this provision, we may exclude any particular area from 
the designation of critical habitat provided that the benefits of such 
exclusion outweigh the benefits of specifying the area as critical 
habitat and that such exclusion would not result in the extinction of 
the species. As such, we believe that the evaluation of the inclusion 
or exclusion of particular areas, or combination thereof, in a 
designation constitutes our regulatory alternative analysis.
    The availability of the draft economic analysis will be announced 
in the Federal Register and in local newspapers so that it is available 
for public review and comments. The draft economic analysis can be 
obtained from our Web site at http://www.fws.gov/southwest/es/Library/, 
or by contacting the Austin Ecological Services Field Office directly 
(see ADDRESSES).

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

    Under the Regulatory Flexibility Act (5 U.S.C. 601 et seq., as 
amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of rulemaking for any proposed or final rule, it must prepare 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 Regulatory 
Flexibility Act (RFA) to require Federal agencies to provide a 
statement of the factual basis for certifying that the rule will not 
have a significant economic impact on a substantial number of small 
entities.
    At this time, the Service lacks the available economic information 
necessary to provide an adequate factual basis for the required RFA 
finding. Therefore, the RFA finding is deferred until we complete the 
draft economic analysis under section 4(b)(2) of the Act and Executive 
Order 12866. This draft economic analysis will provide the required 
factual basis for the RFA finding. Upon completion of the draft 
economic analysis, the Service will publish a notice of availability of 
the draft economic analysis of the proposed designation and reopen the 
public comment period for the proposed designation. The Service will 
include with the notice of availability, as appropriate, an initial 
regulatory flexibility analysis or a certification that the rule will 
not have a significant economic impact on a substantial number of small 
entities accompanied by the factual basis for that determination. The 
Service has concluded that deferring the RFA finding until completion 
of the draft economic analysis is necessary to meet the purposes and 
requirements of the RFA. Deferring the RFA finding in this manner will 
ensure that the Service makes a sufficiently informed determination 
based on adequate economic information and provides the necessary 
opportunity for public comment.

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

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 
1501), the Service makes the following findings:
    (a) 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

[[Page 41694]]

``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; AFDC 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 
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 on to State governments.
    (b) We do not believe that this rule would significantly or 
uniquely affect small governments because it would not produce a 
Federal mandate of $100 million or greater in any year; that is, it is 
not a ``significant regulatory action'' under the Unfunded Mandates 
Reform Act. We do not anticipate that the designation of critical 
habitat will impose obligations on State or local governments. As such, 
a Small Government Agency Plan is not required. However, we will 
further evaluate this issue as we conduct our economic analysis and 
revise this assessment if appropriate.

Executive Order 13211

    On May 18, 2001, the President issued an Executive Order (E.O. 
13211; Actions Concerning Regulations That Significantly Affect Energy 
Supply, Distribution, or Use) on regulations that significantly affect 
energy supply, distribution, and use. Executive Order 13211 requires 
agencies to prepare Statements of Energy Effects when undertaking 
certain actions. While this proposed rule to designate critical habitat 
for the Devils River minnow is a significant regulatory action under 
Executive Order 12866, it is not expected to significantly affect 
energy supplies, distribution, or use. Therefore, this action is not a 
significant energy action, and no Statement of Energy Effects is 
required.

Takings

    In accordance with Executive Order 12630 (``Government Actions and 
Interference with Constitutionally Protected Private Property 
Rights''), we have analyzed the potential takings implications of 
designating critical habitat for the Devils River minnow in a takings 
implications assessment. The takings implications assessment concludes 
that this designation of critical habitat for the Devils River minnow 
would not pose significant takings implications.

Federalism

    In accordance with Executive Order 13132 (Federalism), the rule 
would 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 Devils River minnow 
imposes no additional restrictions to those currently in place and, 
therefore, has little incremental impact on State and local governments 
and their activities. The designation may have some benefit to these 
governments in that the areas that contain the features essential to 
the conservation of the species are more clearly defined, and the PCEs 
of the habitat necessary to the conservation of the species are 
specifically identified. While making this definition and 
identification does not alter where and what federally sponsored 
activities may occur, it may assist these local governments in long-
range planning (rather than have these governments wait for case-by-
case section 7 consultations to occur).

Civil Justice Reform

    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 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 
PCEs within the designated areas to assist the public in understanding 
the habitat needs of the Devils River minnow.

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 OMB under the Paperwork Reduction Act. 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

    It is our position that, outside the Tenth Circuit, we do not need 
to prepare environmental analyses as defined by the NEPA 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 assertion was upheld in the courts 
of the Ninth Circuit (Douglas County v. Babbitt, 48 F.3d 1495 (9th Cir. 
Ore. 1995), cert. denied 116 S. Ct. 698 (1996)).]

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, and the Department 
of Interior's manual at 512 DM 2, we

[[Page 41695]]

readily acknowledge our responsibility to communicate meaningfully with 
recognized Federal Tribes on a government-to-government basis. We have 
determined that there are no tribal lands occupied at the time of 
listing that contain the features essential for the conservation of 
Devils River minnow, and no Tribal lands that are unoccupied areas that 
are essential for the conservation of the Devils River minnow. 
Therefore, we are not proposing to designate critical habitat for the 
Devils River minnow on Tribal lands.

References Cited

    A complete list of all references cited in this rulemaking is 
available upon request from the Field Supervisor, Austin Ecological 
Services Field Office (see ADDRESSES).

Author(s)

    The primary author of this package is the Austin Ecological 
Services Field 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. In Sec.  17.11(h), revise the entry for ``Minnow, Devils River'' 
under ``FISHES'' to read as follows:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                        Species                                                    Vertebrate
--------------------------------------------------------                        population where                                  Critical     Special
                                                            Historic range       endangered or         Status      When listed    habitat       range
           Common name                Scientific name                              threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
              Fishes
 
                                                                      * * * * * * *
Minnow, Devils River.............  Dionda diaboli......  U.S.A., TX, Mexico.  Entire.............  T                       669     17.95(e)           NA
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------

    3. In Sec.  17.95(e), add an entry for ``Devils River Minnow 
(Dionda diaboli)'' in the same alphabetical order that the species 
appears in the table at Sec.  17.11(h) to read as follows:


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (e) Fishes.
* * * * *
Devils River Minnow (Dionda diaboli)
    (1) Critical habitat units are depicted for Val Verde County and 
Kinney County, Texas, on the maps below.
    (2) The primary constituent elements of critical habitat for the 
Devils River minnow are the following habitat components:
    (i) Streams characterized by:
    (A) Areas with slow to moderate water velocities between 10 and 40 
cm/second (4 and 16 in/second) in shallow to moderate water depths 
between approximately 10 cm (4 in) and 1.5 m (4.9 ft), near vegetative 
structure, such as emergent or submerged vegetation or stream bank 
riparian vegetation that overhangs into the water column;
    (B) Gravel and cobble substrates ranging in size between 2 and 10 
cm (0.8 and 4 in) with low or moderate amounts of fine sediment (less 
than 65 percent stream bottom coverage) and low or moderate amounts of 
substrate embeddedness; and
    (C) Pool, riffle, run, and backwater components free of artificial 
instream structures that would prevent movement of fish upstream or 
downstream.
    (ii) High-quality water provided by permanent, natural flows from 
groundwater spring and seeps characterized by:
    (A) Temperature ranging between 17 [deg]C and 29 [deg]C (63 [deg]F 
and 84 [deg]F);
    (B) Dissolved oxygen levels greater than 5.0 mg/l;
    (C) Neutral pH ranging between 7.0 and 8.2;
    (D) Conductivity less than 0.7 mS/cm and salinity less than 1 ppt;
    (E) Ammonia levels less than 0.4 mg/l; and
    (F) No or minimal pollutant levels for copper, arsenic, mercury, 
and cadmium; human and animal waste products; pesticides; fertilizers; 
suspended sediments; petroleum compounds and gasoline or diesel fuels.
    (iii) An abundant aquatic food base consisting of algae attached to 
stream substrates and other associated microorganisms.
    (iv) An aquatic stream habitat either devoid of nonnative aquatic 
species (including fish, plants, and invertebrates) or in which such 
nonnative aquatic species are at levels that allow for healthy 
populations of Devils River minnows.
    (v) Areas within stream courses that may be periodically dewatered 
for short time periods, during seasonal droughts, but otherwise as 
connective corridors between occupied or seasonally occupied areas 
through which the species moves when the area is wetted.
    (3) Critical habitat does not include manmade structures (such as 
buildings, aqueducts, airports, roads, and other paved areas) and the 
land on which they are located existing on the effective date of this 
rule and not containing one or more of the primary constituent 
elements.
    (4) Critical habitat map units. Data layers defining map units were 
created in ArcGIS using the National Hydrography Dataset and 7.5' 
topographic quadrangle maps obtained from U.S. Geological Survey to 
approximate stream channels and calculate distances (stream km and 
stream mi). We made some minor adjustments to stream channels using the 
2004 National Agriculture Imagery Program digital orthophotos obtained 
from the Texas Natural Resources Information System. For each critical 
habitat unit, the upstream and downstream boundaries are described as 
paired geographic coordinates X, Y (meters E, meters N, UTM Zone 14, 
referenced to North American Horizontal Datum 1983). Additionally, 
critical habitat areas include the stream

[[Page 41696]]

channels within the identified stream reaches and areas within these 
reaches up to the bankfull width.
    (5) Note: Overview of critical habitat units for the Devils River 
minnow (Map 1) follows:
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[GRAPHIC] [TIFF OMITTED] TP31JY07.000


[[Page 41697]]


    (6) Unit 1: Devils River Unit, Val Verde County, Texas.
    (i) Unit 1 consists of approximately 43.6 stream km (27.1 stream 
mi) of the Devils River; 1.1 stream km (0.7 stream mi) of Phillips 
Creek; and 2.3 stream km (1.4 stream mi) of Dolan Creek. The upstream 
boundary on the Devils River is at Pecan Springs (UTM 289432E, 
3327875W). The downstream boundary on the Devils River is 3.6 stream km 
(2.2 stream mi) below Dolan Falls (UTM 306454E, 3304426N). Phillips 
Creek is included from the confluence with the Devils River to a point 
1.1 stream km (0.7 stream mi) upstream (UTM 295544E, 3316112N). Dolan 
Creek is included from the confluence with the Devils River to a point 
2.3 stream km (1.4 stream mi) upstream to Dolan Springs (UTM 308084E, 
3309223N). Including all three streams, the total distance in Unit 1 is 
approximately 47.0 stream km (29.2 stream mi).
    (ii) Note: Map of Unit 1, Devils River Unit, (Map 2) follows:

[[Page 41698]]

[GRAPHIC] [TIFF OMITTED] TP31JY07.001


[[Page 41699]]


    (7) Unit 2: San Felipe Creek Unit, Val Verde County, Texas.
    (i) Unit 2 consists of approximately 7.9 stream km (4.9 stream mi) 
on San Felipe Creek; 0.8 stream km (0.5 stream mi) of the outflow of 
San Felipe Springs West; and 0.3 stream km (0.2 stream mi) of the 
outflow of San Felipe Springs East. The upstream boundary on San Felipe 
Creek is the Head Springs (UTM 318813E, 3253702N) located about 1.1 
stream km (0.7 stream mi) upstream of the Jap Lowe Bridge crossing. The 
downstream boundary on San Felipe Creek is in the City of Del Rio 0.8 
stream km (0.5 stream mi) downstream of the Academy Street Bridge 
crossing (UTM 316317E, 3248147N). This unit includes the outflow 
channels from the origin of the two springs, San Felipe Springs West 
(UTM 317039E, 3250850N) and San Felipe Springs East (UTM 317212E, 
250825N), downstream to the confluence with San Felipe Creek. Including 
all three streams, the total distance in Unit 2 is approximately 9.0 
stream km (5.6 stream mi).
    (ii) Note: Map of Unit 2, San Felipe Creek Unit, (Map 3) follows:

[[Page 41700]]

[GRAPHIC] [TIFF OMITTED] TP31JY07.002


[[Page 41701]]


    (8) Unit 3: Pinto Creek Unit, Kinney County, Texas.
    (i) Unit 3 consists of approximately 17.5 stream km (10.9 stream 
mi) on Pinto Creek. The upstream boundary is Pinto Springs (UTM 
359372E, 3254422N). The downstream boundary is 100 m (330 ft) upstream 
of the Highway 90 Bridge crossing of Pinto Creek (UTM 351163E, 
3246179N).
    (ii) Note: Map of Unit 3, Pinto Creek Unit, (Map 4) follows:
    [GRAPHIC] [TIFF OMITTED] TP31JY07.003
    
* * * * *

    Dated: July 19, 2007.
Todd Willens,
Acting Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 07-3678 Filed 7-30-07; 8:45 am]
BILLING CODE 4310-55-C