[Federal Register Volume 68, Number 33 (Wednesday, February 19, 2003)]
[Rules and Regulations]
[Pages 8088-8135]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-3255]



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Part II





Department of the Interior





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Fish and Wildlife Service



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50 CFR Part 17



Endangered and Threatened Wildlife and Plants; Designation of Critical 
Habitat for the Rio Grande Silvery Minnow; Final Rule

  Federal Register / Vol. 68, No. 33 / Wednesday, February 19, 2003 / 
Rules and Regulations  

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AH91


Endangered and Threatened Wildlife and Plants; Designation of 
Critical Habitat for the Rio Grande Silvery Minnow

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule; notice of availability.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), designate 
critical habitat for the Rio Grande silvery minnow (Hybognathus amarus) 
(silvery minnow), an endangered species under the Endangered Species 
Act of 1973, as amended (Act). On June 6, 2002, we proposed that 212 
miles (mi) (339 kilometers (km)) be designated as critical habitat for 
the silvery minnow. The silvery minnow critical habitat designation in 
the Rio Grande extends from Cochiti Dam, Sandoval County, New Mexico 
(NM) downstream to the utility line crossing the Rio Grande, a 
permanent identified landmark in Socorro County, NM, a total of 
approximately 157 mi (252 km), referred to as the ``middle Rio 
Grande.'' The designation also includes the tributary Jemez River from 
Jemez Canyon Dam in NM to the upstream boundary of Santa Ana Pueblo, 
which is not included. The critical habitat designation defines the 
lateral extent (width) as those areas bounded by existing levees or, in 
areas without levees, 300 feet (ft) (91.4 meters (m)) of riparian zone 
adjacent to each side of the bankfull stage of the middle Rio Grande. 
The Pueblo lands of Santo Domingo, Santa Ana, Sandia, and Isleta within 
this area are not included in the final critical habitat designation. 
Except for these areas, the final remaining portion of the silvery 
minnow's occupied range in the middle Rio Grande in NM is being 
designated as critical habitat. This publication also provides notice 
of the availability of the final economic analysis and the final 
Environmental Impact Statement (EIS) for this final rule.
    This final rule and EIS are being issued pursuant to a court order. 
On November 21, 2000, the United States District Court for the District 
of New Mexico, in Middle Rio Grande Conservancy District v. Babbitt, 
206 F. Supp. 2d 1156 (D.N.M. 2000), set aside the July 6, 1999, 
critical habitat designation for the minnow and ordered us to issue 
both an EIS pursuant to the National Environmental Policy Act (NEPA) 
and a new proposed rule designating critical habitat for the silvery 
minnow.

DATES: This final rule is effective March 21, 2003.

ADDRESSES: Comments and materials received, as well as supporting 
documentation used in the preparation of this final rule, are available 
for public inspection, by appointment, during normal business hours at 
the New Mexico Ecological Services Field Office, 2105 Osuna Road NE, 
Albuquerque, NM 87113.
    You may obtain copies of the final rule, the economic analysis, or 
the final EIS from the field office address above or by calling 505-
346-2525. All documents are also available from our Web site at http://ifw2es.fws.gov/Library/.
    If you would like copies of the regulations on listed wildlife or 
have questions about prohibitions and permits, contact the U.S. Fish 
and Wildlife Service, Division of Endangered Species, P.O. Box 1306, 
Albuquerque, NM 87103.

FOR FURTHER INFORMATION CONTACT: Field Supervisor, New Mexico 
Ecological Services Field Office (see ADDRESSES section above); 
telephone: 505-346-2525. Division of Endangered Species (see ADDRESSES 
section above); telephone 505-248-6920; facsimile 505-248-6788.

SUPPLEMENTARY INFORMATION:

Background

    The Rio Grande silvery minnow is one of seven species in the genus 
Hybognathus found in the United States (Pflieger 1980). The species was 
first described by Girard (1856) from specimens taken from the Rio 
Grande near Fort Brown, Cameron County, TX. It is a stout silvery 
minnow with moderately small eyes and a small, slightly oblique mouth. 
Adults may reach 3.5 inches (in) (90 millimeters (mm)) in total length 
(Sublette et al. 1990). Its dorsal fin is distinctly pointed with the 
front of it located slightly closer to the tip of the snout than to the 
base of the tail. The fish is silver with emerald reflections. Its 
belly is silvery white, its fins are plain, and barbels are absent 
(Sublette et al. 1990).
    This species was historically one of the most abundant and 
widespread fishes in the Rio Grande Basin, occurring from Espanola, NM, 
to the Gulf of Mexico (Bestgen and Platania 1991). It was also found in 
the Pecos River, a major tributary of the Rio Grande, from Santa Rosa, 
NM, downstream to its confluence with the Rio Grande (Pflieger 1980). 
The silvery minnow is extirpated from the Pecos River and also from the 
Rio Grande downstream of Elephant Butte Reservoir and upstream of 
Cochiti Reservoir (Bestgen and Platania 1991). The current distribution 
of the silvery minnow is limited to the Rio Grande between Cochiti Dam 
and Elephant Butte Reservoir. Throughout much of its historic range, 
the decline of the silvery minnow has been attributed to modification 
of the flow regime (hydrological pattern of flows that vary seasonally 
in magnitude and duration, depending on annual precipitation patterns 
such as runoff from snowmelt) and channel drying resulting from 
impoundments, water diversion for agriculture, stream channelization, 
and perhaps both interactions with non-native fish and decreasing water 
quality (Cook et al. 1992; Bestgen and Platania 1991; Service 1999; 
Buhl 2001).
    Much of the species' life history information detailed below comes 
from studies conducted within the middle Rio Grande, the current range 
of the silvery minnow. Nevertheless, we believe that our determinations 
for other areas outside of the middle Rio Grande, but within the 
historic range of the silvery minnow, are consistent with the data 
collected to date on the species' ecological requirements (e.g., 
Service 1999).
    The role of the plains minnow (Hybognathus placitus) in the decline 
and extirpation of the silvery minnow from the Pecos River is 
uncertain; however, the establishment of the plains minnow coincided 
with the disappearance of the silvery minnow from the Pecos River 
(Bestgen and Platania 1991; Cook et al. 1992). Cook et al. (1992) 
believed that the non-native plains minnow was introduced into the 
Pecos drainage prior to 1964, and was probably the result of the 
release of ``bait minnows'' collected from the Arkansas River drainage. 
It is unclear, however, if populations of the native silvery minnow 
were depleted prior to the introduction of the plains minnow, or if the 
reduction and extirpation of the silvery minnow was a consequence of 
the interactions between the two species (C. Hoagstrom, U.S. Fish and 
Wildlife Service, pers. comm. 2001). One theory is that the plains 
minnow may be more tolerant of modified habitats and, therefore, was 
able to replace the silvery minnow in the degraded reaches of the Pecos 
River. Nevertheless, the plains minnow has experienced population 
declines within its native range from highly variable water levels, 
unstable streambeds, and fluctuating water temperatures (Cross et al. 
1985, cited in

[[Page 8089]]

Taylor and Miller 1990). Although the interactions (e.g., hybridization 
or competition) between the silvery minnow and the introduced plains 
minnow are believed by some to be one of the primary causes for the 
extirpation of the silvery minnow in the Pecos River, this hypothesis 
is unsubstantiated (Hatch et al. 1985; Bestgen et al. 1989; Cook et al. 
1992). Currently, New Mexico State University is conducting research on 
the plains minnow and silvery minnow to determine if the two species 
hybridize. These studies are ongoing and results should be available in 
2003 (C. Caldwell, U.S. Geological Survey, Biological Resources 
Division pers. comm. 2002).
    Within its native range, the plains minnow is sympatric (occurs at 
the same localities) with other species of Hybognathus, but is 
separated ecologically from them. For example, the plains minnow is 
found in the main river channel where the substrate is predominantly 
sand, whereas related species such as the western silvery minnow 
(Hybognathus argyritis) predominate in backwaters and protected areas 
with little to no current and sand or silt substrate (Pflieger 1997). 
Consequently, if the silvery minnow and plains minnow do not hybridize, 
they may be ecologically segregated and able to co-exist.
    The plains minnow and silvery minnow appear to have little in the 
way of behavioral or physiological isolating mechanisms and may 
hybridize (Cook et al. 1992); yet the combined effects of habitat 
degradation (i.e., modification of the flow regime, channel drying, 
water diversion, and stream channelization) may be another potential 
explanation for the silvery minnow's extirpation from the Pecos River 
(Bestgen and Platania 1991; C. Hoagstrom, pers. comm. 2001). We 
acknowledge that no conclusive data exist to determine the cause of 
extirpation of the silvery minnow from the Pecos River.
    The silvery minnow has also been extirpated from the Rio Grande 
downstream of Elephant Butte Reservoir, NM, to the Gulf of Mexico, 
Texas (TX), including the river reach within Big Bend National Park 
(Hubbs et al. 1977; Bestgen and Platania 1991). Reasons for the 
species' extirpation in the lower Rio Grande are also uncertain. The 
last documented collection of a silvery minnow in the Big Bend area was 
1961, but reexamination of that specimen revealed it was a plains 
minnow (Bestgen and Propst 1996). Therefore, the last silvery minnow 
from the lower Rio Grande was apparently collected in the late 1950s 
(Trevino-Robinson 1959; Hubbs et al. 1977; Edwards and Contreras-
Balderas 1991).
    Prior to measurable human influence on the middle Rio Grande, 
starting in the 1300's, (Biella and Chapman 1977), the Rio Grande was a 
perennially flowing, aggrading river with a shifting sand substrate. In 
general, the river was slightly sinuous and braided, and freely 
migrated across the floodplain. Strong evidence now suggests that the 
middle Rio Grande started drying up on a fairly regular basis only 
after the development of Colorado's San Luis Valley in the 1870's. 
Prior to this, there are only two examples of its flow ceasing, during 
prolonged, severe droughts in 1752 and 1861. Over the past century, and 
particularly in the last few decades, the middle Rio Grande has been 
frequently dewatered, particularly in the river reach from Isleta 
Diversion Dam to the San Acacia Diversion Dam (Isleta reach) and the 
reach from San Acacia Diversion Dam to Elephant Butte Reservoir (San 
Acacia reach) (Middle Rio Grande Conservancy District (MRGCD) 1999; 
Scurlock and Johnson 2001; Scurlock 1998).
    Decline of the species in the middle Rio Grande probably began in 
1916 when the gates of Elephant Butte Dam were closed. Construction of 
the dam signaled the beginning of an era of dam construction on the 
mainstem Rio Grande that resulted in five major mainstem dams within 
the silvery minnow's historic range (Shupe and Williams 1988). These 
dams (Cochiti, Elephant Butte, Caballo, International Amistad, and 
International Falcon) allowed manipulation and diversion of the river's 
flow. Often this manipulation severely altered the flow regime and 
likely precipitated the decline of the silvery minnow (Bestgen and 
Platania 1991). Water management and use has resulted in a large 
reduction of suitable habitat for the silvery minnow. Lack of water is 
likely the single most important limiting factor for the survival of 
the species (Service 1999). Agriculture accounts for 90 percent of the 
water consumption in the middle Rio Grande (Bullard and Wells 1992). 
The average annual diversion of water in the middle Rio Grande by the 
MRGCD was 535,280 acre-feet (af) for the period from 1975 to 1989 (U.S. 
Bureau of Reclamation (BOR) 1993). The silvery minnow historically 
survived low flow periods because such events were infrequent and of 
lesser magnitude, and there were no diversion dams to restrict free 
movement of silvery minnows in the river (59 FR 36988). Concurrent with 
construction of the mainstem dams was an increase in the abundance of 
non-native fish (largemouth bass (Micropterus salmoides), smallmouth 
bass (M. dolomieu)) as these species were stocked into the reservoirs 
created by the dams (e.g., Cochiti Reservoir) (Sublette et al. 1990). 
Once established, these species often completely replaced the native 
fish fauna (Propst et al. 1987; Propst 1999).
    Development of agriculture and the growth of cities within the 
historic range of the silvery minnow resulted in a decrease in the 
quality of river water caused by municipal and agricultural runoff 
(i.e., sewage and pesticides) that may have also adversely affected the 
range and distribution of the silvery minnow. Historically there were 
four other small native fish species (speckled chub (Macrohybopsis 
aestivalis); Rio Grande shiner (Notropis jemezanus); phantom shiner 
(Notropis orca); and Rio Grande bluntnose shiner (Notropis simus 
simus)) within the middle Rio Grande that had similar reproductive 
attributes, but these species are now either extinct or extirpated 
(Platania 1991).
    The various life history stages of the silvery minnow require 
shallow waters with a sandy and silty substrate that is generally 
associated with a meandering river that includes sidebars, oxbows, and 
backwaters (C. Hoagstrom, pers. comm, 2001; Bestgen and Platania 1991; 
Platania 1991). However, physical modifications to the Rio Grande over 
the last century--including the construction of dams, levees, and 
channelization of the mainstem--have altered much of the habitat that 
is necessary for the species to persist (Service 1999). Channelization 
has straightened and shortened mainstem river reaches; increased the 
velocity of the current; and altered riparian vegetation, instream 
cover, and substrate composition (BOR 2001a). Adult silvery minnows 
occur in shallow braided runs over sand substrate, but rarely in 
habitat with substrate of gravel or cobble (Platania 1991; Dudley and 
Platania 1997; Platania and Dudley 1997; Remshardt et al. 2001).
    The silvery minnow is a pelagic spawning species; i.e., its eggs 
flow in the water column. The silvery minnow is the only surviving 
small, native pelagic spawning minnow in the middle Rio Grande, and its 
range has been reduced to only 5 percent of its historic extent. 
Although the silvery minnow is a hearty fish, capable of withstanding 
many of the natural stresses of the desert aquatic environment, most 
individual silvery minnows live only one year (Bestgen and Platania 
1991). Thus, a successful annual spawn is key to the survival of the 
species (Platania and Hoagstrom 1996; Service 1999; Dudley and Platania 
2001, 2002b). The

[[Page 8090]]

silvery minnow's range has been so greatly restricted that the species 
is extremely vulnerable to catastrophic events, such as a prolonged 
period of low or no flow (i.e., the loss of all surface water) (59 FR 
36988; Dudley and Platania 2001).
    In the middle Rio Grande, the spring runoff coincides with and may 
trigger the silvery minnow's spawn (Platania and Hoagstrom 1996; 
Service 1999; Dudley and Platania 2001). For example, 1,850 cubic feet 
per second (cfs) of water was released from Cochiti Reservoir on May 
13, 2002, to provide for silvery minnow spawning. Following the 
release, a significant spawning event occurred in the middle Rio 
Grande. During a spawn, semibuoyant (floating) eggs drift downstream in 
the water column (Smith 1999; Dudley and Platania 2001) (see ``Primary 
Constituent Elements'' section of this final rule for further 
information on spawning). However, diversion dams are believed to act 
as instream barriers and prevent silvery minnows from moving upstream 
after hatching (Service 2001b; Dudley and Platania 2001; 2002a). In 
fact, the continued downstream displacement and decline of the silvery 
minnow in the middle Rio Grande is well documented (Dudley and Platania 
2001).
    During the irrigation season (approximately March 1 to October 31 
of each year) in the middle Rio Grande, silvery minnow often become 
stranded in the diversion channels (or irrigation ditches), where they 
are unlikely to survive (Smith 1999; Lang and Altenbach 1994). For 
example, when the irrigation water in the diversion channels is used on 
agricultural fields, the possibility for survival of silvery minnows in 
the irrigation return flows (excess irrigation water that flows from 
agricultural fields and is eventually returned to the river) is low, 
because silvery minnows perish in canals because of unsuitable habitat, 
dewatering, or predation (Lang and Altenbach 1994). Unscreened 
diversion dams also entrain (trap) silvery minnow fry (fish that have 
recently emerged from eggs) and semibuoyant eggs (Smith 1998; 1999). 
However, some irrigation water is returned to the river via irrigation 
waterways in the reach of the middle Rio Grande from the Isleta reach, 
which helps sustain flow in certain segments of this reach. 
Nevertheless, we do not have evidence that these riverside drains offer 
suitable refugia for the silvery minnow.
    Perhaps even more problematic for the silvery minnow in the middle 
Rio Grande are drought years during the irrigation season when there 
may be little supplemental water (water that is used to augment river 
flows) available. Compounding this problem is stream bed aggradation 
(i.e., the river bottom is rising due to sedimentation) below San 
Acacia, NM, where the bed of the river is now perched above the bed of 
the low flow conveyance channel (LFCC). The LFCC is immediately 
adjacent to and parallels the Rio Grande for approximately 75 mi (121 
km) and was designed to expedite delivery of water to Elephant Butte 
Reservoir, pursuant to the Rio Grande Compact of 1939. The LFCC 
diverted water from the Rio Grande from 1959 to 1985. Because the river 
bed is now above the LFCC, waters in the mainstem of the river are 
drained from the river bed into the LFCC. The LFCC has the capacity to 
take approximately 2,000 cfs of the river's flow, via gravity. If 
natural river flow is 2,000 cfs or less, the LFCC can dewater the Rio 
Grande from its heading at the San Acacia Diversion Dam south to 
Elephant Butte Reservoir.
    However, the LFCC has not been fully operational since 1985 because 
of siltation of the lower end (i.e., stream bed aggradation) at 
Elephant Butte Reservoir. Even without water diversion into the LFCC, 
seepage from the river to the LFCC is occurring and causing some loss 
of surface flows in the river channel (BOR 2001a). In effect, water is 
drained from the Rio Grande into the LFCC thereby resulting in water 
losses in the reach from the San Acacia reach. During some years this 
can result in prolonged recurring periods of low or no flow.
    It is believed that, historically, the silvery minnow was able to 
withstand periods of drought primarily by retreating to pools and 
backwater refugia, and swimming upstream to repopulate upstream 
habitats (Deacon and Minckley 1974; J. Smith, U.S. Fish and Wildlife 
Service, pers. comm. 2001). Platania (1995) posits that after prolonged 
recurring periods of low or no flow the silvery minnow may have been 
able to repopulate downstream habitat the following year because eggs 
drifted from upstream populations (Platania 1995). Although able to 
survive droughts historically through such movements, the present-day 
middle Rio Grande dries and dams prevent upstream movement. As a result 
silvery minnows can become trapped in dewatered reaches and may die in 
isolated pools before the river becomes wetted again. The inability of 
the population to find adequate refugia during prolonged recurring 
periods of low or no flow and to repopulate extirpated reaches creates 
a very unstable population (Service 2001b).
    In some isolated pools, Smith and Hoagstrom (1997) and Smith (1999) 
documented complete mortality of silvery minnows in the middle Rio 
Grande in both 1996 and 1997 during prolonged periods of low or no 
flow. These studies documented both the relative size of the isolated 
pool (i.e., estimated surface area and maximum depth) in relation to 
pool longevity (i.e., number of days the isolated pool existed) and the 
fish community within isolated pools. Isolated pools found during these 
conditions typically only lasted for about 48 hours before drying up 
completely (Smith 1999). Those isolated pools that persisted longer 
than 48 hours lost greater than 81 percent of their estimated surface 
area and greater than 26 percent of their maximum depth within 48 
hours. Moreover, isolated pools receive no surface inflow, water 
temperatures increase, and dissolved oxygen decreases; depending on 
location, size, and duration of the prolonged recurring periods of low 
or no flow, these factors may result in the death of all fish (Tramer 
1977; Mundahl 1990; Platania 1993b; Ostrand and Marks 2000; Ostrand and 
Wilde 2001). Therefore, when periods of low or no flow are longlasting 
(over 48 hours), complete mortality of silvery minnows in isolated 
pools can occur.
    Formation of isolated pools also increases the risk of predation of 
silvery minnows in drying habitats. Predators, primarily fish and 
birds, have been observed in high numbers in the middle Rio Grande, 
consuming fish in drying, isolated pools where those fish become 
concentrated and are more vulnerable to predation (J. Smith, pers. 
comm. 2001).
    The potential for prolonged recurring periods of low or no flow in 
the middle Rio Grande becomes particularly significant for the silvery 
minnow below the San Acacia Diversion Dam, where most silvery minnows 
have been recently captured. In the river reach above (north of) the 
San Acacia Diversion Dam, return flows from current irrigation 
operations and other activities are routed back into the mainstem of 
the middle Rio Grande. At times, this can provide a fairly consistent 
flow in particular stretches of the Isleta reach. However, at the San 
Acacia Diversion Dam, once diversions are made (i.e., to irrigation 
canals, as well as seepage losses to the LFCC) the return flows 
continue in off-river channels (with a few exceptions at Brown's Arroyo 
and the 10-mile outfall of the LFCC) until they enter Elephant Butte 
Reservoir. Thus, unlike in the Isleta reach, the silvery minnow does 
not receive the benefit of irrigation return flows in the San Acacia 
reach.

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Previous Federal Action

    We proposed to list the silvery minnow as an endangered species 
with critical habitat on March 1, 1993 (58 FR 11821). The comment 
period, originally scheduled to close on April 30, 1993, was extended 
to August 25, 1993 (58 FR 19220; April 13, 1993). That extension 
allowed us to conduct public hearings and to receive additional public 
comments. Public hearings were held in Albuquerque and Socorro, NM, on 
the evenings of June 2 and 3, 1993, respectively. After a review of all 
comments received in response to the proposed rule, we published the 
final rule to list the silvery minnow as endangered on July 20, 1994 
(59 FR 36988).
    Section 4(a)(3) of the Act requires that the Secretary, to the 
maximum extent prudent and determinable, designate critical habitat at 
the time a species is listed as endangered or threatened. Our 
regulations (50 CFR 424.12(a)(2)) state that critical habitat is not 
determinable if information sufficient to perform required analyses of 
the impacts of the designation is lacking or if the biological needs of 
the species are not sufficiently well known to permit identification of 
an area as critical habitat. At the time the silvery minnow was listed, 
we found that critical habitat was not determinable because there was 
insufficient information to allow us to perform the required analyses 
of the impacts of the designation.
    We contracted for an economic analysis of the proposed critical 
habitat designation in September 1994, and a draft analysis was 
prepared and provided to us on February 29, 1996. The draft document 
was then provided to all interested parties on April 26, 1996. That 
mailing included 164 individuals and agencies, all affected Pueblos in 
the valley, all county commissions within the occupied range of the 
species, and an additional 54 individuals who had attended the public 
hearings on the proposed listing and who had requested that they be 
included on our mailing list, particularly for the economic analysis. 
At that time, we notified the public that, because of a moratorium on 
final listing actions and determinations of critical habitat imposed by 
Public Law 104-6, no work would be conducted on the analysis or on the 
final decision concerning critical habitat. However, we solicited 
comments from the public and agencies on the document for use at the 
time such work resumed.
    On April 26, 1996, the moratorium was lifted. Following the waiver 
of the moratorium, we reactivated the listing program that had been 
shut down for over a year and faced a backlog of 243 proposed species 
listings. In order to address that workload, we published, on May 16, 
1996, our Listing Priority Guidance for the remainder of Fiscal Year 
1996 (61 FR 24722). That guidance identified the designation of 
critical habitat as the lowest priority upon which we could expend 
limited funding and staff resources. Subsequent revisions of the 
guidance for Fiscal Years 1997 (December 5, 1996; 61 FR 64475) and for 
1998-1999 (May 8, 1998; 63 FR 25502) retained critical habitat as the 
lowest priority for the listing program within the Service. Thus, no 
work resumed on the economic analysis.
    On February 22, 1999, in Forest Guardians v. Babbitt, Civ. No. 97-
0453 JC/DIS, the United States District Court for the District of New 
Mexico ordered us to publish a final determination with regard to 
critical habitat for the silvery minnow within 30 days. The deadline 
was subsequently extended by the court to June 23, 1999. On July 6, 
1999, we published a final designation of critical habitat for the 
silvery minnow (64 FR 36274), pursuant to the court order.
    On November 21, 2000, the United States District Court for the 
District of New Mexico, in Middle Rio Grande Conservancy District v. 
Babbitt, 206 F. Supp. 2d 1156 (D.N.M. 2000), set aside the July 6, 
1999, critical habitat designation because we had not issued an EIS, 
hence we were ordered to issue both an EIS pursuant to the National 
Environmental Policy Act (NEPA) and a new proposed rule designating 
critical habitat for the silvery minnow. This final rule and the EIS 
are being issued pursuant to that court order.
    On April 5, 2001, we mailed approximately 500 copies of a 
preproposal notification letter to the 6 middle Rio Grande Indian 
Pueblos (Cochiti, Santo Domingo, San Felipe, Santa Ana, Sandia, and 
Isleta), various governmental agencies, interested individuals, and the 
New Mexico Congressional delegation. The letter informed them of our 
intent to prepare an EIS for the proposed designation of critical 
habitat for the silvery minnow and announced public scoping meetings 
pursuant to NEPA. On April 17, 23, 24, and 27, 2001, we held public 
scoping meetings in Albuquerque, NM; Carlsbad, NM; Fort Stockton, TX; 
and Socorro, NM, respectively. We solicited oral and written comments 
and input. We were particularly interested in obtaining additional 
information on the status of the species or information concerning 
threats to the species. The comment period closed June 5, 2001. We 
received approximately 40 comments during the EIS scoping process. 
During April 2001, we contracted with Industrial Economics Incorporated 
for an economic analysis and the Institute of Public Law at the 
University of New Mexico School of Law for an EIS on the proposed 
critical habitat designation.
    Following the closing of the scoping comment period, we outlined 
possible alternatives for the EIS. We held a meeting on September 12, 
2001, to solicit input on the possible alternatives from the Rio Grande 
Silvery Minnow Recovery Team (Recovery Team) and other invited 
participants including individuals from the Carlsbad Irrigation 
District, Fort Sumner Irrigation District, the States of New Mexico and 
Texas, and potentially affected Pueblos and Tribes. Following this 
meeting, we sent letters to the Recovery Team and other invited 
participants, including Tribal entities and resource agencies in NM and 
TX, to solicit any additional information (particularly biological, 
cultural, social, or economic data) that may be pertinent to the 
economic analysis or EIS. We received 10 comments in response to our 
requests for additional information. We fully considered the 
information provided in the comment letters as we developed the 
alternatives analyzed in the draft EIS, which included the proposed 
rule as our preferred alternative.
    On June 6, 2002, we proposed that 212 mi (339 km) be designated as 
critical habitat for the silvery minnow (67 FR 39206). The comment 
period for the proposed rule, draft EIS, and draft Economic Analysis 
was originally scheduled to close on September 4, 2002, but was 
extended until October 2, 2002 (67 FR 57783).
    In this final rule, we determine that a river reach in the lower 
Rio Grande in Big Bend National Park downstream of the park boundary to 
the Terrell/Val Verde County line, TX (lower Rio Grande), and a river 
reach in the middle Pecos River, from Sumner Dam to Brantley Dam in De 
Baca, Chaves, and Eddy Counties, NM (middle Pecos River), are essential 
to the conservation of the silvery minnow. However, these areas are not 
designated as critical habitat because of our analysis under section 
4(b)(2) (see ``Exclusions Under Section 4(b)(2) of the Act'' section of 
this rule). This critical habitat designation includes the middle Rio 
Grande from Cochiti Dam to the utility line crossing the Rio Grande 
just east of the Bosque Well as demarcated on USGS Paraje Well 7.5 
minute quadrangle (1980), Socorro County, NM, with the Universal 
Transverse Mercator

[[Page 8092]]

(UTM) coordinates of UTM Zone 13: 311474 E, 3719722 N, as referenced 
with the 1927 North American Datum (NAD27). The designation also 
includes the tributary Jemez River from Jemez Canyon Dam to the 
upstream boundary of Santa Ana Pueblo, which is not included (see the 
``Regulation Promulgation'' section of this rule for exact descriptions 
of boundaries of critical habitat), and no other reaches within the 
historic range of the silvery minnow. We have also not included four 
areas of the middle Rio Grande in the critical habitat because of 
Tribal management plans and other relevant issues (see ``Relationship 
of Critical Habitat to Pueblo Lands under Section 3(5)(A) and 
Exclusions Under Section 4(b)(2)'' section of this rule). Therefore, we 
are only designating some sections of the river reaches currently 
occupied by the silvery minnow.
    This final rule is selected as the preferred alternative in the 
final EIS, pursuant to NEPA, which we were required to prepare under 
court order from the United States District Court for the District of 
New Mexico, in Middle Rio Grande Conservancy District v. Babbitt, 206 
F. Supp. 2d 1156 (D.N.M. 2000). The two reaches referenced above (i.e., 
middle Pecos River and lower Rio Grande) were also analyzed in the EIS 
and Economic Analysis. We followed the procedures required by the Act, 
NEPA, and the Administrative Procedure Act during this Federal 
rulemaking process. Therefore, we solicited public comment on all 
reaches identified in the proposed rule as essential, including whether 
any of these or other areas should be excluded from the final 
designation pursuant to section 4(b)(2). As required by law, we have 
considered all comments received on the proposed rule, the draft EIS, 
and the draft economic analysis before making this final determination.

Recovery Plan

    Restoring an endangered or threatened species to the point where it 
is recovered is a primary goal of our endangered species program. To 
help guide the recovery effort, we prepare recovery plans for most of 
the listed species native to the United States. Recovery plans describe 
actions considered necessary for conservation of the species, establish 
criteria for downlisting or delisting the species, and estimate time 
and cost for implementing the recovery measures needed. Although a 
recovery plan is not a regulatory document (i.e., recovery plans are 
advisory documents because there are no specific protections, 
prohibitions, or requirements afforded to a species solely on the basis 
of a recovery plan), the information contained in the Rio Grande 
Silvery Minnow Recovery Plan (Recovery Plan) was considered in 
developing this critical habitat designation.
    On July 1, 1994, the Recovery Team was established by the Service 
pursuant to section 4(f)(2) of the Act and our cooperative policy on 
recovery plan participation, a policy intended to involve stakeholders 
in recovery planning (July 1, 1994; 59 FR 34272). Stakeholder 
involvement in the development of recovery plans helps minimize the 
social and economic impacts that could be associated with recovery of 
endangered species. Numerous individuals, agencies, and affected 
parties were involved in the development of the Recovery Plan or 
otherwise provided assistance and review (Service 1999). On July 8, 
1999, we finalized the Recovery Plan (Service 1999), pursuant to 
section 4(f) of the Act.
    The Recovery Plan recommends recovery goals for the silvery minnow, 
as well as procedures to better understand the biology of the species. 
The primary goals of the Recovery Plan are to: (1) Stabilize and 
enhance populations of silvery minnow and its habitat in the middle Rio 
Grande valley and (2) reestablish the silvery minnow in at least three 
other areas of its historic range (Service 1999). The reasons for 
determining that these three areas were necessary for recovery include: 
(1) Consideration of the biology of the species (e.g., few silvery 
minnows live more than 12 to 14 months, indicating the age-1 fish 
(i.e., all fish born in 2000 that remain alive in 2001 would be age-1 
fish) are almost entirely responsible for perpetuation of the species); 
(2) the factors in each reach that may inhibit or enhance 
reestablishment and security of the species vary among areas; and (3) 
it is unlikely that any single event would simultaneously eliminate the 
silvery minnow from three geographic areas (Service 1999).
    In accordance with the Recovery Plan, we have initiated a captive 
propagation program for the silvery minnow (Service 1999; Brooks 2001). 
Silvery minnows are currently being propagated at five facilities in NM 
and one in South Dakota (SD); one additional NM facility will come on-
line in 2003. We currently have silvery minnows housed at: (1) The 
Service's Dexter National Fish Hatchery and Technology Center, NM; (2) 
the Service's Mora National Fish Hatchery and Technology Center, NM; 
(3) the City of Albuquerque's Biological Park, NM; (4) the New Mexico 
State University, NM; (5) the New Mexico Department of Game and Fish's 
Rock Lake State Fish Hatchery, NM; and (6) the U.S. Geological Survey 
Biological Resources Division's Yankton Laboratory, SD (J. Brooks, 
pers. comm., 2002). Progeny of these fish are being used to augment the 
middle Rio Grande silvery minnow population, but could also be used in 
future augmentation or reestablishment programs for the silvery minnow 
in other river reaches (J. Remshardt, New Mexico Fishery Resources 
Office, pers. comm. 2001).
    We have also salvaged and transplanted silvery minnows within the 
middle Rio Grande in recent years (Service 1996, 1998, 1999, 2000, 
2001, 2002). Approximately 225,500 silvery minnow larvae and adults 
have been released (i.e., stockings from captive bred fish or 
translocated from downstream reaches) since May 1996 (J. Remshardt, 
U.S. Fish and Wildlife Service, pers. comm. 2001). For example, in late 
2001, the University of New Mexico (UNM) released 11,900 silvery 
minnows into the San Acacia Reach. In June 2002, we released 2,500 
marked silvery minnows within the Angostura Reach. These fish were 
marked to determine the movement of silvery minnows in the wild. 
Results of studies of the effectiveness of these releases will be 
useful for evaluating future efforts to reintroduce the species. These 
results should be available in 2003 (R. Dudley and S. Platania, UNM, 
pers. comm. 2002).
    We have also continued working with the Recovery Team since the 
Recovery Plan was finalized. We believe this critical habitat 
designation and our conservation strategy (see ``Exclusions Under 
Section 4(b)(2) of the Act'' section below) are consistent with the 
Recovery Plan (Service 1999). The purpose of the Recovery Plan is to 
outline the research and data collection activities that will identify 
measures to ensure the conservation of the silvery minnow in the wild. 
We believe this critical habitat designation and our conservation 
strategy are consistent with the recommendations of the Recovery Plan 
and Recovery Team.

Summary of Comments and Recommendations

    In the June 6, 2002, proposed rule, we requested all interested 
parties to submit comments or information concerning the designation of 
critical habitat for the silvery minnow (67 FR 39206). During the 
comment period, we held public hearings in Socorro and Albuquerque on 
June 25, and 26, 2002, respectively. We published newspaper notices 
inviting public comment and announcing the public hearings in the

[[Page 8093]]

following newspapers in NM: Albuquerque Journal, Albuquerque Tribune, 
Socorro Defensor Chieftain, Sante Fe New Mexican, and Las Cruces Sun. 
Transcripts of these hearings are available for inspection (see 
ADDRESSES section). The comment period was originally scheduled to 
close on September 4, but was extended until October 2, 2002 (September 
12, 2002; 67 FR 57783). We contacted all appropriate State and Federal 
agencies, Tribes, county governments, scientific organizations, and 
other interested parties and invited them to comment. On June 6, 2002, 
we hosted a teleconference to provide a short presentation and answer 
questions by reporters on all aspects of the proposed critical habitat 
designation, the draft economic analysis, and draft EIS. We also 
provided notification of these documents through e-mail, telephone 
calls, letters, and news releases faxed and/or mailed to affected 
elected officials, media outlets, local jurisdictions, Tribes, and 
interest groups. We also published all of the associated documents on 
our Region 2 Internet site following their release on June 6, 2002.
    We solicited five independent experts who are familiar with this 
species to peer review the proposed critical habitat designation. Only 
one of the peer reviewers submitted comments, and these supported the 
proposed designation. We also received a total of 34 oral and 54 
written comments. Of the oral comments, 10 supported critical habitat 
designation and 24 opposed designation. Of the written comments, 17 
supported critical habitat designation, 22 opposed designation, and 15 
were neutral or provided additional information. We reviewed all 
comments received for substantive issues and new data regarding 
critical habitat and the silvery minnow, the draft economic analysis, 
and the draft EIS. In the following summary of issues we address all 
comments received on all three documents during the comment periods and 
public hearing testimony. Comments of a similar nature are grouped into 
issues.

Issue 1: Biological Concerns

    (1) Comment: Some commenters state that the extent of critical 
habitat proposed by us is inadequate to address survival and recovery 
of the species (e.g., critical habitat for the silvery minnow should be 
expanded beyond the current proposal). Recommendations for additional 
areas designated include the Rio Grande from Caballo to the NM-TX 
border, the area from the confluence of the Rio Conchas to the 
downstream boundary of Big Bend National Park, and the Pecos River from 
Sumner to Brantley Reservoir.
    Our Response: Our analysis of the following two areas--(1) the 
river reach in the middle Pecos River, NM, from Sumner Dam to Brantley 
Dam in De Baca, Chaves, and Eddy Counties, NM; and (2) the river reach 
in the lower Rio Grande in Big Bend National Park downstream of the 
National Park boundary to the Terrell/Val Verde County line, TX--finds 
that the benefits of excluding these areas from the designation of 
critical habitat outweigh the benefits of including them (see 
``Exclusions Under Section 4(b)(2)'' section). Although we believe 
these areas are essential to the conservation of the silvery minnow, 
these areas are not designated as critical habitat.
    It is critical to the recovery of the silvery minnow that we 
reestablish the species in areas outside of its current occupied range. 
We believe that one of the goals of the Recovery Plan can be fulfilled 
by reestablishing the silvery minnow in areas of its historic range 
using the flexibility provided for in section 10(j) of the Act. In 
order to achieve recovery for the silvery minnow, we need assistance 
from local stakeholders to ensure the success of reestablishing the 
minnow in areas of its historic range. Use of section 10(j) is meant to 
encourage local cooperation through management flexibility. Critical 
habitat is often viewed negatively by the public since it is not well 
understood and there are many misconceptions about how it affects 
private landowners (E. Hein, U.S. Fish and Wildlife Service, pers. 
comm, 2002). It is important for recovery of this species that we have 
the support of the public when we move toward meeting the second 
recovery goal of reestablishing the species in areas of its historic 
range.
    The reasons why other areas of the silvery minnow's historic range 
were not designated as critical habitat are detailed within the 
``Reach-by-Reach Analysis'' section below. If, in the future, we 
determine from information or analysis that those areas designated in 
this final rule need further refinement or if we identify and determine 
additional areas to be essential to the conservation of the species and 
requiring special management or protection, we will evaluate whether a 
revision of critical habitat is warranted at that time.
    (2) Comment: The current proposal for critical habitat for the 
silvery minnow is contrary to the recommendations of the Rio Grande 
Silvery Minnow Recovery Team and the Recovery Plan. The proposed 
designation is deficient in its omission of critical habitat in the 
``three other areas within its historic range'' as required by the 
Recovery Plan. Our proposal to not designate the lower Rio Grande as 
critical habitat has no factual basis.
    Our Response: It is important to note that we utilized the 
recommendations of the Recovery Team in the Recovery Plan, consistent 
with this definition of conservation, to conclude that the middle Rio 
Grande and the middle Pecos River from Sumner Dam to Brantley Dam, NM, 
and the lower Rio Grande from the upstream boundary of Big Bend 
National Park downstream through the area designated as a wild and 
scenic river to the Terrell/Val Verde County line, TX, are ``essential 
to the conservation of'' the silvery minnow. Although the middle Pecos 
River and the lower Rio Grande are not designated as critical habitat, 
we believe they are important for the recovery of the silvery minnow. 
Thus, we concur with the Recovery Plan that reestablishment of the 
silvery minnow within additional geographically distinct areas, within 
its historical range, is necessary to ensure the minnow's survival and 
recovery (Service 1999). However, recovery is not achieved by 
designating critical habitat. The Act provides for other mechanisms 
that will provide for reestablishment of the minnow outside of the 
middle Rio Grande and the eventual recovery of the silvery minnow. In 
addition, please see responses 1 and 44 for information related to this 
particular issue.
    (3) Comment: The Service appears to be greatly concerned that 
critical habitat could jeopardize the trust and spirit of cooperation 
that has been established over the last several years because critical 
habitat designation would be viewed as an unwarranted and unwanted 
intrusion in the middle Pecos and lower Rio Grande. However, the same 
arguments can be made in the middle Rio Grande.
    Our Response: The middle Pecos and lower Rio Grande are essential 
to the conservation of the silvery minnow. Still, the silvery minnow 
has been extirpated from these areas of its historic range and we 
believe that the appropriate means to potentially reestablish the 
species is through use of the 10(j) experimental population rule (see 
``Exclusions Under Section 4(b)(2)'' section). We also have not 
included areas within the middle Rio Grande where we believe adequate 
special management is in place and because of other relevant issues 
(see ``Relationship of Critical Habitat to Pueblo Lands under Section 
3(5)(A) and Exclusions Under Section 4(b)(2)'' section).

[[Page 8094]]

However, we determine that other areas of the middle Rio Grande meet 
the definition of critical habitat, and we did not exclude these areas 
under section 4(b)(2) based upon economic or other relevant impacts.
    We are actively involved with ensuring conservation benefits to the 
listed species within the middle Rio Grande by participating in a 
collaborative working group to develop a long-term strategy/solution 
(Middle Rio Grande Endangered Species Act Collaborative Program). We 
believe this type of cooperative program is an important opportunity to 
achieve and facilitate conservation of the minnow, while allowing water 
activities to continue.
    (4) Comment: It is well documented that the Rio Grande has 
historically gone dry. The current proposal to keep the river running 
throughout the year is not reasonable, feasible, or necessary. You are 
attempting to create a habitat that has never existed. The proposed 
rule does not identify minimum flow requirements to maintain the 
primary constituent elements. Critical habitat will only increase the 
``bureaucratic red tape,'' not silvery minnow habitat.
    Our Response: Critical habitat primarily focuses on the maintenance 
of habitat features identified as primary constituent elements. 
Critical habitat does not serve to create these features where they do 
not currently exist.
    We agree that some areas designated as critical habitat within the 
middle Rio Grande have the potential for periods of low or no flow 
under certain conditions (see ``Primary Constituent Elements'' 
section). We also recognize that the critical habitat designation 
specifically includes some areas that have lost flow periodically 
(MRGCD 1999; Scurlock and Johnson 2001; Scurlock 1998). We nevertheless 
believe these areas are essential to the conservation of the silvery 
minnow because they likely serve as connecting corridors for fish 
movement between areas of sufficient flowing water (e.g., see Deacon 
and Minckley 1974; Eberle et al. 1993). Additionally, we believe the 
designated critical habitat is essential for the natural channel 
geomorphology (the topography of the river channel) to maintain 
habitat, such as pools, by removing or redistributing sediment during 
high flow events (e.g., see Simpson et al. 1982; Middle Rio Grande 
Biological Interagency Team 1993). Therefore, we believe that the 
inclusion of an area that has the potential for periods of low or no 
flow as critical habitat will ensure the long-term survival and 
recovery of silvery minnow. As such, we believe that the primary 
constituent elements as described in this final rule provide for a flow 
regime that allows for short periods of low or no flow.
    The primary constituent elements identified below provide a 
qualitative description of those physical and biological features 
necessary to ensure the conservation of the silvery minnow. We did not 
identify quantitative estimates of specific minimum thresholds (e.g., 
minimum flows or depths), because we believe these estimates vary 
seasonally and annually, and by river reach within the designated 
critical habitat. Thus, we believe these thresholds are appropriately 
enumerated through section 7 provisions 7(a)(1) and 7(a)(2) (e.g., see 
Service 2001b), which can be easily changed if new information reveals 
effects to critical habitat in a manner or extent not previously 
considered (see 50 CFR 402.16(b)).
    We based this final rule on the best available scientific 
information, including the recommendations in the Recovery Plan 
(Service 1999). We have designated only river reaches that currently 
contain the primary constituent elements (described below) during all 
or a part of the year and that are currently occupied by the minnow. We 
did not include river reaches where the current or potential 
suitability for the silvery minnow is unknown. Consequently, we are not 
attempting to create habitat conditions or minimum flow requirements, 
but rather, we will review projects that have a Federal nexus to ensure 
that any proposed actions do not adversely affect the current primary 
constituent elements to the extent that the designated critical habitat 
will be adversely modified or destroyed.
    (5) Comment: The silvery minnow is doing very well in its current 
situation and is not vulnerable to a single catastrophic event. The 
captive breeding program is flourishing and it seems reasonable that 
you could release many millions of silvery minnows each spring. 
Therefore, you should not condemn the river to support a species that 
has an arbitrary designation and is not truly endangered.
    Our Response: The purpose of the Act is to conserve listed species 
and the ecosystems on which they depend. Relegating a species to 
captivity does not conserve the ecosystem on which they depend. 
Controlled propagation is not a substitute for addressing factors 
responsible for an endangered or threatened species' decline. 
Therefore, our first priority is to recover wild populations in their 
natural habitat wherever possible, without resorting to the use of 
controlled propagation. This position is fully consistent with the Act. 
Moreover, there has been insufficient time to develop a captive 
propagation management plan that captures the majority of genetic 
variability of the minnow in the wild to maximize the low genetic 
diversity in captively propagated silvery minnows (Turner 2002).
    We reviewed the best scientific and commercial data available to 
determine that the silvery minnow should be classified as an endangered 
species on July 20, 1994 (59 FR 36988). Procedures found at section 
4(a)(1) of the Act, and regulations (50 CFR Part 424) issued to 
implement the listing provisions of the Act were followed. A species 
may be determined to be an endangered or threatened species due to one 
or more of the five factors described in section 4(a)(1) of the Act. 
There is no evidence to suggest that the silvery minnow is recovered, 
and recovery goals outlined in the Recovery Plan have not yet been met. 
Therefore, we do not agree that the silvery minnow is ``doing very well 
in its current situation.'' Additionally, the silvery minnow occupies 
less than 5 percent of its historic range, and the likelihood of 
extinction from catastrophic events is high because of its limited 
range (Hoagstrom and Brooks 2000, Service 1999).
    (6) Comment: In the proposed rule, the Service suggests that the 
primary constituent elements for the silvery minnow and Pecos bluntnose 
shiner are compatible. However, if this were the case, the silvery 
minnow would not be extirpated from the Pecos River.
    Our Response: We continue to believe that the primary constituent 
elements for the Pecos bluntnose shiner critical habitat (e.g., clean 
permanent water; a main river channel habitat with sandy substrate; and 
a low velocity flow (February 20, 1987; 52 FR 5295)) are compatible 
with our conservation strategy for repatriating the silvery minnow. 
There are no conclusive data to substantiate any reasons for 
extirpation of the silvery minnow from the Pecos River. Primary 
constituent elements are those physical and biological habitat 
components that are essential for the conservation of the species, and 
are not determined based upon the species' presence. The absence of 
silvery minnows from the Pecos River does not mean that the minnow's 
primary constituent elements are not present. (Also refer to the 
``Background'' section for information on the role of the plains minnow 
(Hybognathus placitus) in the decline and extirpation of the silvery 
minnow from the Pecos River).

[[Page 8095]]

    (7) Comment: One of the most significant threats to native fish in 
the southwestern United States is non-native fish; however, the Service 
did not provide any information on whether non-native fish affect the 
silvery minnow or its habitat.
    Our Response: In the proposed critical habitat designation rule, we 
stated: ``Habitat alteration and loss, and non-native competition, 
predation, and other effects are inextricably intertwined and have 
contributed substantially to the endangered status of the silvery 
minnow (Service 1999; Dudley and Platania 2001). Furthermore, habitat 
alteration has been a significant contributor to non-native fish 
invasion, competition, and adverse effects. In turn, non-native species 
have likely contributed significantly to the inability of native fish, 
such as the silvery minnow, to persist in altered environments (Hubbs 
1990; Propst 1999)'' (June 6, 2002; 67 FR 39206).
    (8) Comment: There is a notable lack of data in your reports 
concerning the plains minnow found within the middle Rio Grande.
    Our Response: Although the plains minnow was found infrequently in 
a survey of bait-fishing stores within the Rio Grande Basin (Schmitt 
1975), the plains minnow has never been documented in the wild within 
the middle Rio Grande (R. Dudley, American Southwest Ichthyological 
Research Foundation, pers. comm., 2002; K. Bestgen, Colorado State 
University, Larval Fish Laboratory, pers. comm., 2002). The silvery 
minnow and plains minnow can be distinguished from each other by 
morphological and genetic differences (Bestgen and Propst 1996; Cook et 
al. 1992). Therefore, we believe that ``a lack of data'' is reflective 
of a lack of presence of the plains minnow in the middle Rio Grande.
    (9) Comment: Critical habitat could result in the loss of flood 
pulses for uses such as periodic flooding of the bosque.
    Our Response: The silvery minnow requires a spike in early spring 
to trigger spawning (Platania and Dudley 2000). Critical habitat will 
not result in the loss of this pulse of water. In fact, this hydrologic 
event could also periodically flood some areas of the bosque (bosque is 
the riparian areas adjacent to the Rio Grande).
    (10) Comment: One commenter believes the Service overlooked 
important information that silvery minnows can bury in the wet sand and 
survive extensive periods, especially when the river bed is dry. This 
commenter states that when the river is dry, silvery minnows have been 
found by digging in the sand.
    Our Response: There is no information in the scientific literature 
or provided by biologists researching the silvery minnow to indicate 
that the species can either bury underground or survive in the wet sand 
when the river is dry. Available evidence indicates that silvery 
minnows die only minutes after being removed from water.
    (11) Comment: The Service should consider the use of irrigation 
ditches to recover the silvery minnow.
    Our Response: Ephemeral or perennial irrigation canals and ditches, 
including the LFCC (i.e., downstream of the southern boundary of Bosque 
del Apache National Wildlife Refuge to the headwaters of Elephant Butte 
Reservoir) do not offer suitable refugia and are not useful for 
conservation of the silvery minnow because they do not contain the 
primary constituent elements and the habitat is not sufficient to 
support viable populations of silvery minnow for extended periods of 
time (see also BOR 2001c). Silvery minnows found in canals and ditches 
are believed to represent silvery minnows that became entrapped due to 
the diversion of irrigation water from the mainstem middle Rio Grande. 
Nevertheless, we are aware that a study is being conducted by New 
Mexico State University to evaluate the usefulness of irrigation canals 
and ditches to the silvery minnow (Thompson 2002). We will assess the 
results of this study when they are available.
    (12) Comment: Why does the Service indicate that agricultural 
runoff is detrimental to the silvery minnow, when the return flows are 
an important source of water for the species?
    Our Response: We recognize that under current irrigation 
operations, the delivery of irrigation water and associated return 
flows play an important role in supporting fish survival in the lower 
reaches of the river. The return flows also help to provide water to 
meet Rio Grande Compact delivery obligations. Irrigation water 
deliveries to MRGCD and the six middle Rio Grande Pueblos provide 
``carriage'' water that facilitates the more efficient delivery of 
supplemental water to benefit the silvery minnow. However, as noted in 
the background section, development of agriculture and the growth of 
cities within the historic range of the silvery minnow may have 
resulted in a decrease in the quality of river water through municipal 
and agricultural runoff (i.e., sewage and pesticides).

Issue 2: Procedural and Legal Compliance

    (13) Comment: The U.S. Army Corps of Engineers (Corps) should be 
held responsible for the plight of the silvery minnow because they 
constructed Cochiti Dam and drastically altered the species' habitat.
    Our Response: The effects of past and ongoing human and natural 
factors leading to the current status of the silvery minnow is called 
the environmental baseline. The environmental baseline is a snapshot of 
the species' status at any point in time, and is updated when we 
conduct a section 7 biological opinion. No single entity can be held 
responsible for the status of the silvery minnow. However, the Corps is 
(as are many other entities) included in the Middle Rio Grande 
Endangered Species Act Collaborative Program and is part of the long-
term solution to develop and implement activities to conserve the 
minnow.
    (14) Comment: We must specify in the final rule for critical 
habitat whether the experimental population under section 10(j) of the 
Act would be essential or nonessential.
    Our Response: When we designate a population as experimental, 
section 10(j) of the Act requires that we determine whether that 
population is either essential or nonessential to the continued 
existence of the species on the basis of the best available 
information. Any future recovery efforts, including repatriation of the 
species to areas of its historical range under section 10(j) of the 
Act, will be conducted in accordance with the pertinent sections of the 
Act, NEPA, and Federal rulemaking procedures. A NEPA analysis is 
necessary to carefully consider information concerning every 
significant environmental impact among all the alternatives and select 
a preferred alternative. We find that nonessential designations garner 
wider and more meaningful public support. However, at this time we 
cannot determine the type of 10(j) rule that may be proposed for the 
minnow.
    (15) Comment: The establishment of experimental populations is 
purely speculative because according to the Service's regulations, the 
establishment of an experimental population requires an agreement among 
the Service, affected States, Federal agencies, and landowners. An 
agreement is unlikely to happen.
    Our Response: We believe that the use of section 10(j) will 
encourage local cooperation through management flexibility. Our 
regulations state that we shall consult with appropriate State fish

[[Page 8096]]

and wildlife agencies, local government entities, affected Federal 
agencies, and affected private landowners in developing and 
implementing experimental population rules (50 CFR 17.81(d)). As noted 
above, any future recovery efforts, including reintroduction of the 
species to areas of its historic range, will be conducted in accordance 
with NEPA and the Act.
    (16) Comment: Executive Orders 12866 and 12988 appear to apply to 
the proposed designation of critical habitat.
    Our Response: We again read through the comments and information 
provided concerning Executive Orders 12866 (``Regulatory Planning and 
Review'') and 12988 (``Civil Justice Reform''). While the commenter did 
not adequately explain the rationale for why they believe our initial 
determinations in the proposed critical habitat designation were 
inadequate, we found nothing to warrant changing our original 
determinations about the applicability of these Executive Orders.
    (17) Comment: How can critical habitat include the Isleta reach 
that the District Court for the District of New Mexico has determined 
could be dry? The District Court order provides for the potential 
draining of Heron Reservoir. If the current drought continues through 
2003, potentially 75 percent of critical habitat could be dry. The 
court order from the District Court changes all of the previous 
analyses and conclusions concerning critical habitat designation. The 
Service has not considered Judge Parker's recent court order to provide 
water for the silvery minnow. The Service must consider and analyze all 
sources of storage water that will now be used for the silvery minnow.
    Our Response: On September 23, 2002, the District Court for the 
District of New Mexico ordered the following: (1) The BOR must provide 
sufficient flows of water for the remainder of 2002 to maintain a flow 
of 50 cfs at San Acacia Diversion Dam, and to maintain a flow in the 
Albuquerque Reach from Angostura Diversion Dam to Isleta Diversion Dam; 
(2) if necessary to meet these flow requirements for the remainder of 
2002, the BOR must release water from Heron Reservoir in 2002; and (3) 
the Federal Government must compensate those, if any, whose contractual 
rights to water are reduced in order to meet the flow requirements (Rio 
Grande Silvery Minnow v. Keys, Civ. No. 99-1320 JP/RLP-ACE).
    In a court order issued October 16, 2002, the Tenth Circuit Court 
of Appeals stayed the District Court's order (Rio Grande Silvery Minnow 
v. Keys, Civ. No. 02-2254, 02-2255, 02-2267). The court order from the 
District Court for the District of New Mexico is currently under appeal 
in the Tenth Circuit Court of Appeals and a written decision has not 
been issued. On the basis of the consultation history of the silvery 
minnow, we do not anticipate that the voluntary supplemental water 
program discussed in responses to comments 56 and 57 will change. 
Because we anticipate that supplemental flows to avoid destruction or 
adverse modification of critical habitat will be similar, if not 
identical, to what is currently required to avoid jeopardizing the 
species, we do not believe that critical habitat will result in 
additional flow requirements during consultation. Nevertheless, future 
section 7 consultations will evaluate whether proposed actions 
jeopardize the continued existence of the silvery minnow or adversely 
modify or destroy critical habitat. Each consultation will be evaluated 
on a case-by-case basis following our regulations (50 CFR part 402).
    (18) Comment: The Service should consider water table augmentation 
to satisfy the primary constituent elements rather than flow 
augmentation. Habitat restoration activities need to move forward 
quickly because the supplemental water program cannot continue at the 
current level.
    Our Response: We appreciate these and other numerous suggestions we 
received regarding special management considerations. Water table 
augmentation and habitat restoration activities may provide for the 
maintenance and improvement of one or more of the primary constituent 
elements important for the species' long-term conservation. These types 
of special management activities, as well as other measures to avoid or 
minimize incidental take, will be reviewed during consultations with 
Federal agencies. (Refer to our response to comment 3 above for 
information on the collaborative working group.)
    (19) Comment: The Service should consider the affidavits that were 
filed in September 2002, in response to the court case (Rio Grande 
Silvery Minnow v. Keys, Civ. No. 99-1320 JP/RLP-ACE). These include: 
Dr. Thomas Wesche, Subhas K. Shah, Sterling Grogan, Dr. Richard Valdez, 
Christopher S. Altenbach, John Whipple, John M. Stomp III, Rolf-
Schmidt-Peterson, F. Lee Brown, and Walter G. Hines.
    Our Response: We have considered the affidavits and found that none 
of the information appears to contradict the relevant conclusions for 
this final designation of critical habitat.
    (20) Comment: The Service needs to consult with the State 
Department and Mexico as directed by Executive Order 12114 because the 
designation of critical habitat in the lower Rio Grande may have 
international implications.
    Our Response: We are not designating critical habitat along the 
international border in the lower Rio Grande. We did not consult with 
the State Department and Mexico because we believe that the action of 
designating critical habitat within the middle Rio Grande will not have 
significant effects on the environment outside the geographical borders 
of the United States and its territories.
    (21) Comments: The economic analysis and proposed critical habitat 
demonstrate a complete disregard for the unique culture and historic 
heritage associated with agriculture within the middle Rio Grande.
    Our Response: As described in the final EIS, we are aware of the 
unique heritage associated with agriculture within the middle Rio 
Grande. Still, the regulatory requirements associated with critical 
habitat do not apply to any agricultural activities, including farming 
or livestock grazing, or any other activity carried out on private land 
that does not require and/or involve a Federal permit, authorization, 
or funding. Because the silvery minnow is listed as endangered, Federal 
agencies already are required to consult with us on any of their 
actions that are likely to adversely affect the species and to ensure 
that their actions do not jeopardize the species' continued existence, 
regardless of whether critical habitat has been designated. Therefore, 
we do not believe the designation of critical habitat for the silvery 
minnow will result in any significant additional regulatory burden on 
landowners or affect the use of their private property.
    (22) Comment: No one was aware that the silvery minnow was going to 
be listed in 1994. Once a species is listed, critical habitat appears 
to be an unavoidable consequence.
    Our Response: On February 19, 1991, about 80 prelisting proposal 
letters of inquiry were mailed to various governmental agencies, 
knowledgeable individuals, and the New Mexico Congressional delegation. 
On March 20, 1992, we held a meeting in Albuquerque, NM, with various 
interested governmental and private entities to explore existing or 
potential flexibility in water delivery schedules that might avoid 
dewatering of the Rio Grande within the range of the silvery minnow. In 
the March 1, 1993, proposed rule and associated notifications, all 
interested parties were requested to submit factual reports or 
information that might contribute to the

[[Page 8097]]

development of a final rule. The comment period originally scheduled to 
close on April 30, 1993, was extended until August 25, 1993 (58 FR 
19220), to conduct public hearings and allow submission of additional 
comments. We also published notices of the proposed listing in five 
local newspapers and mailed copies of the proposed rule to list the 
silvery minnow as endangered to 148 different government agencies, 
private organizations, and interested individuals, including all 
counties having lands that border on or were within the area being 
proposed for critical habitat designation. Two public hearings were 
also held. Prior to listing the silvery minnow as endangered, we fully 
met the requirements of the Act for public notification. As discussed 
in the ``Previous Federal Action'' section of this rule, section 4 of 
the Act requires us to designate critical habitat at the time of 
listing, unless a determination is made that such designation is not 
prudent or not determinable. If a not determinable determination is 
made, we would have an additional year to make such a determination.
    (23) Comment: The proposed rule and associated documents did not 
mention how critical habitat and section 7 consultation may affect the 
National Pollution Discharge Elimination System, water quality issues, 
or flood control structures.
    Our Response: The EIS analyzed the impacts to the Albuquerque 
Metropolitan Arroyo Flood Control Authority, National Pollution 
Discharge Elimination System (NPDES) permitting, and other impacts on 
water quality (also see ``Effect of Critical Habitat Designation'' 
below). The final EIS found that the silvery minnow will most likely be 
protected by existing water quality standards, and that changes to 
current EPA discharge permitting activities are expected to be minimal, 
although the possibility exists for EPA's consultations with us to 
change as more becomes known about the water quality needs of the 
silvery minnow.
    It is important to note that section 7(a)(2) of the Act requires 
that Federal agencies ensure that actions they fund, authorize, or 
carry out are not likely to result in the ``destruction or adverse 
modification'' of critical habitat. In our regulations at 50 CFR 
402.02, we define destruction or adverse modification as ``direct or 
indirect alteration that appreciably diminishes the value of critical 
habitat for both the survival and recovery of a listed species. Such 
alterations include, but are not limited to, alterations adversely 
modifying any of those physical or biological features that were the 
basis for determining the habitat to be critical.'' Where no such 
Federal agency action is involved, critical habitat designation has no 
effect on private landowners, State, or Tribal activities.
    (24) Comment: How will critical habitat affect the City of 
Albuquerque's Drinking Water Project?
    Our Response: Analysis of effects to listed species will be 
addressed in detail during section 7 consultation between the BOR and 
us. The section 7 consultation will determine whether the City of 
Albuquerque's Drinking Water Project jeopardizes the continued 
existence of the silvery minnow or adversely modifies or destroys 
critical habitat. As we have in the past, we will continue to work with 
the City of Albuquerque on conservation issues for the silvery minnow 
(see our response to comment 57 below).
    (25) Comment: The Service proposed a 300-ft (91.4-m) lateral width 
for the boundary of critical habitat, but there is no site specific 
information to determine whether any particular area even has a 
floodplain or whether the floodplain, if present, extends 300 ft (91.4 
m).
    Our Response: We recognize that the lateral width of riparian areas 
fluctuates considerably in the middle Rio Grande. The 300-ft (91.4-m) 
lateral width includes the riparian zone, if present, that is adjacent 
to each side of the middle Rio Grande. We believe the riparian zone 
adjacent to the river channel provides an important function for the 
protection and maintenance of the primary constituent elements and is 
essential to the conservation of the species.
    Developed lands within the 300-ft (91.4-m) lateral width are not 
considered critical habitat because they do not include the primary 
constituent elements. These lands were specifically excluded from the 
designation and include: developed flood control facilities, existing 
paved roads, bridges, parking lots, dikes, levees, diversion 
structures, railroad tracks, railroad trestles, water diversion and 
irrigation canals outside of natural stream channels, the low flow 
conveyance channel, active gravel pits, cultivated agricultural land, 
and residential, commercial, and industrial developments.
    (26) Comment: The Service only considered excluding the Cochiti or 
San Acacia Reach. No other reaches were considered for exclusion within 
the middle Rio Grande.
    Our Response: We did not include four areas within the Angostura 
and Isleta Reaches (see ``Relationship of Critical Habitat to Pueblo 
Lands under Section 3(5)(A) and Exclusions Under Section 4(b)(2)'' 
section below). Additionally, we solicited comments or suggestions from 
the public, other concerned governmental agencies, the scientific 
community, industry, or any other interested party concerning the 
reasons why any habitat should or should not be determined to be 
critical habitat as provided by section 4 of the Act, including whether 
the benefits of excluding areas will outweigh the benefits of including 
areas as critical habitat. We requested information on any lands 
included in the proposed rule for which there was special management 
and protection in place such that those lands could not be included as 
critical habitat. We reviewed and considered all of the information and 
comments received and concluded that special management or protection 
is provided only for the management plans we received during the 
comment period from the Pueblos of Santo Domingo, Santa Ana, Sandia, 
and Isleta. Consequently, no other areas were determined to be not 
essential for inclusion for the final critical habitat designation.
    (27) Comment: The City of Albuquerque requested that we exclude 
existing projects, facilities, and structures within the designated 
critical habitat.
    Our Response: The City of Albuquerque did not provide a list 
describing the specific projects, facilities, or structures. However, 
some existing facilities and structures are excluded from the 
designation because they do not include the primary constituent 
elements. See response to comment 25 and the ``Regulation 
Promulgation'' section of this rule for specific exclusions.
    (28) Comment: The designation of critical habitat will seize 
control of our water through Federal regulations and Federal courts. 
Elected officials and State Engineers are constitutionally responsible 
for decisions on state water management.
    Our Response: An area designated as critical habitat is not a 
refuge or sanctuary for the species. Listed species are protected by 
the Act whether or not they are in an area designated as critical 
habitat.
    We published required determinations in the proposed and final 
rules, including one in accordance with Executive Order 13132, which 
considered whether this rule has significant Federalism effects (see 
``Required Determinations'' section below). We requested information 
from and coordinated development of the

[[Page 8098]]

proposed and final rules with appropriate resource agencies in NM and 
TX (e.g., during the EIS scoping and proposed rule public comment 
period). During the open comment period for the proposed rule, we met 
on several occasions with the New Mexico Interstate Stream Commission 
(NMISC) to further coordinate and address issues concerning the 
designation of critical habitat for the silvery minnow.
    We do not anticipate that this regulation will intrude on State 
policy or administration, change the role of the Federal or State 
government, or affect fiscal capacity. For example, we have conducted 
two formal consultations, one of which included a formal conference, 
with the Corps and BOR, and non-Federal entities over actions related 
to water operations on the middle Rio Grande (Service 2001b, 2002a). In 
our experience, the vast majority of such projects can be successfully 
implemented with, at most, minor changes that avoid significant 
economic impacts to project proponents.
    (29) Comment: Other than the initial scoping letter, the City of 
Socorro or Bernalillo County was not contacted for either development 
of the EIS or economic analysis. Several other commenters voiced 
concern that they were not directly contacted for their opinions on the 
economic impacts of critical habitat designation.
    Our Response: On April 5, 2001, the Federal Register notice 
announcing public scoping meetings and development of a draft EIS was 
mailed to the Mayor of Socorro and the Socorro County Board of 
Commissioners and to Bernalillo County Commissioners. Moreover, on 
October 4, 2001, our EIS contractor mailed letters to the Chairman of 
Socorro County Board of Commissioners and the Bernalillo County 
Manager, and on August 22, 2001, a letter was mailed to the Mayor of 
the City of Socorro requesting specific information for the development 
EIS. We did not receive any response to these letters. Economic 
Analysis contractors utilized databases with information provided by 
the County of Socorro.
    It was not feasible to contact every potential stakeholder in order 
for us to develop a draft economic analysis. We believe we were able to 
understand the issues of concern to the local communities on the basis 
of our review of public comments submitted on the proposed rule and 
draft economic analysis, transcripts from public hearings, and detailed 
discussions with 65 local governments. To clarify issues, we solicited 
information and comments from representatives of Federal, State, 
Tribal, and local government agencies, as well as some landowners.
    (30) Comment: The amount of time and information available were 
insufficient for more detailed responses.
    Our Response: On June 6, 2002, we published the proposed critical 
habitat determination in the Federal Register (67 FR 39205), announced 
public hearings, and invited public comment for 90 days. The public 
hearings were held on June 25 and 26. These public hearings were also 
announced in several newspapers (described above under the introduction 
of the ``Summary of Comments and Recommendations'' section). On June 6, 
we mailed the proposed rule and information on how to obtain the draft 
economic analysis and draft EIS to over 600 different interested 
parties. All of the documents were also available at the hearings, from 
us by request, or by download from our Web site. On August 28, we 
mailed a prepublication notice of the comment period extension. The 
comment period was subsequently extended and closed on October 2, 2002.
    (31) Comment: The Service held public hearings only to fulfill a 
legal obligation and will not pay attention to any public comment.
    Our Response: All comments received, including oral comments 
provided at the public hearing, were carefully evaluated before we made 
a final determination. In fact, we used special management plans 
received during the public comment period and other relevant issues to 
determine specific areas to not include for the final critical habitat 
designation.
    (32) Comment: Some commenters asked whether critical habitat 
designation would affect the building or maintenance of flood control 
systems (e.g., levee) to protect the town of Socorro and other areas 
within the designation.
    Our Response: Levees are specifically excluded from the designation 
(see ``Regulation Promulgation'' section below). Since 1995, the Corps 
has entered into section 7 consultation with us regarding its water 
operations, flood control and levee maintenance, bridge construction, 
section 404 permitting under the Clean Water Act, and other activities. 
Through this process, we have reviewed various Corps projects to ensure 
that the continued existence of the silvery minnow is not jeopardized 
and that previously designated critical habitat was not adversely 
modified or destroyed. Since the silvery minnow was federally listed, 
no Corps projects have been stopped, delayed, or altered in a 
significant way resulting from section 7 consultation. The draft EIS 
noted that the Corps will likely propose a design and develop a plan 
for construction that would permit levees to be rehabilitated without 
adversely modifying critical habitat.
    It is also important to note that we have a special category of 
section 7 consultation, and corresponding regulations (50 CFR 402.05) 
called ``Emergency Consultations.'' The consultation process does not 
affect the ability of an agency to respond to emergency events such as 
levee failure or fire. During emergency events, our primary objective 
is to provide recommendations for minimizing adverse effects to listed 
species without impeding response efforts. During emergency events, 
protecting human life and property comes first every time. 
Consequently, no constraints for protection of listed species or their 
critical habitat are ever recommended if they place human lives or 
structures (e.g., houses) in danger. We are currently working with many 
of our Federal partners to provide technical assistance, coordination, 
and, in some instances, section 7 consultation for proactive projects 
to reduce the potential for emergency events (e.g., wildland urban 
interface fuels management).
    (33) Comment: The designation of critical habitat will impose 
section 9 restrictions against taking of silvery minnow in areas that 
do not currently have those restrictions (e.g., within the headwaters 
of Elephant Butte Reservoir).
    Our Response: Section 9 of the Act prohibits the harm or harassment 
of individuals of listed species. There are no section 9 take 
prohibitions for critical habitat. Within the middle Rio Grande, 
prohibitions against take are in effect regardless of whether or not 
critical habitat has been designated because we consider this area 
occupied by the silvery minnow. Whether or not a species has designated 
critical habitat, it is protected from any actions resulting in an 
unlawful take under section 9 of the Act.
    (34) Comment: The Service needs to provide specific analyses on 
whether each reach contains or is void of primary constituent elements. 
The constituent elements described are vague and violate 50 CFR 
424.12(c), lack sufficient detail and justification, and should include 
a more specific description that defines what constitutes critical 
habitat. Several commenters were concerned that the mapping lacked 
precision for use by the public and the critical habitat boundaries are 
ambiguous and difficult

[[Page 8099]]

to identify. Information is available for us to refine the 300-foot 
lateral width including National Wetlands Inventory data. The Rio 
Grande Compact Engineer Advisor from the State of Colorado submitted 
comments in October 2001 that suggested we use the ``daily'' Elephant 
Butte Reservoir water line as the lower terminus of critical habitat. 
Comments submitted in October 2002 suggested that the boundary as 
proposed would change from day to day and create total chaos in the 
operation of Elephant Butte Dam and Reservoir.
    Our Response: The critical habitat designation includes the middle 
Rio Grande from Cochiti Dam to the utility line crossing the Rio Grande 
with UTM coordinates of UTM Zone 13: 311474 E, 3719722 N, just east of 
the Bosque Well demarcated on USGS Paraje Well 7.5 minute quadrangle 
(1980), Socorro County, NM. The designation also includes the tributary 
Jemez River from Jemez Canyon Dam to the upstream boundary of Santa Ana 
Pueblo, which is not included. (see the ``Regulation Promulgation'' 
section of this rule for exact descriptions of boundaries of critical 
habitat). We believe that with the revision to the downstream terminus 
of critical habitat, the boundary should be clear. Moreover, this final 
rule describes in the greatest detail possible the primary constituent 
elements important to the silvery minnow. In addition, please see 
responses to comments 26 and 45 for information related to this 
particular issue.
    In our proposal and this final rule, we indicate our belief that 
the primary constituent elements provide for a flow regime that allows 
for short periods of low or no flow. In the proposal, we also 
highlighted the difficulties in describing the existing conditions of 
areas with low or no flow and solicited further information to refine 
the primary constituent elements and how they relate to the existing 
conditions (e.g., flow regime). We noted that flow requirements are 
dynamic and change during the year and among years. The status of the 
species also contributes to specific flow requirements at specific 
areas or stream gages, for example. Consultation under section 7, 
rather than regulation, is the proper procedure for outlining specific 
flow requirements.
    During the comment period we requested, but did not receive, any 
information that would either enable us to further refine the primary 
constituent elements or conduct further analysis on whether particular 
reaches contained or lacked one or more primary constituent elements. 
Further, while we welcome and encourage additional studies on the 
biological requirements of the silvery minnow, we believe the best 
available information has been used in defining the primary constituent 
elements necessary for the species' conservation. Nevertheless, we 
recognize that not all of the developed lands area within the 
boundaries of the designation will contain the habitat components 
essential to the conservation of the silvery minnow. For this reason, 
some developed lands are excluded by definition (see the ``Regulation 
Promulgation'' section below).
    We considered National Wetlands Inventory data and other sources of 
information to refine the lateral width of the designation. Because of 
the dynamic nature of the Rio Grande and the corresponding ephemeral 
nature of wetland and riparian vegetation adjacent to the river (Middle 
Rio Grande Biological Interagency Team 1993; Taylor et al. 1999; BOR 
2001c), we believe that using National Wetlands Inventory or other data 
to select the lateral width of critical habitat would not be consistent 
with our regulations (50 CFR 424.12(c)), which do not allow us to use 
ephemeral reference points. Consequently, we are designating critical 
habitat using specific limits and reference points.
    (35) Comment: Depletion of stored water in reservoirs by 
supplemental water releases to benefit critical habitat will affect 
BOR's ability to deliver water to the MRGCD.
    Our Response: According to BOR (2001c), the voluntary supplemental 
water program for the silvery minnow is not expected to have an adverse 
affect on the MRGCD. Thus, it is the Service's understanding that BOR's 
voluntary supplemental water program will be consistent with existing 
laws and contracts to ensure delivery of water to the MRGCD and to the 
six middle Rio Grande Pueblos (Cochiti, Santo Domingo, San Felipe, 
Santa Ana, Sandia, and Isleta) (BOR 2001c). Moreover, section 7 
consultation has been occurring regardless of critical habitat 
designation because of the Federal listing alone. We note that despite 
one of the State's worst droughts in 50 years, ``the Rio Grande helped 
some farms grow bumper crops of alfalfa * * *'' (Albuquerque Tribune 
December 16, 2002).
    (36) Comment: One commenter believes that the proposed rule should 
be incontrovertible, but it is currently laced with supposition and 
conjecture, and it contains no conclusive data.
    Our Response: As required by section 4(b)(2), the Service used the 
best available scientific and commercial data. In accordance with our 
policy published on July 1, 1994 (59 FR 34270), we sent the proposed 
rule to five peer reviewers to solicit their expert opinions. The 
purpose of such review is to ensure listing decisions are based on 
scientifically sound data, assumptions, and analyses. We received only 
one reply from our peer reviewers. The peer reviewer concluded that our 
proposal was scientifically sound.
    (37) Comment: It does not appear that your EIS analyzed evaporation 
losses from restoration activities.
    Our Response: This issue is discussed in the EIS. We concluded that 
the extent to which riverine and riparian restoration results in a net 
gain or net loss to the water supply depends on the design of the 
project.
    (38) Comment: Several commenters suggested that the San Acacia 
reach be excluded from the designation because of economic or other 
relevant impacts.
    Our Response: This is described as alternative D in the EIS. The 
analysis in the EIS found a lower likelihood that habitat essential for 
the conservation of the silvery minnow would be preserved if this reach 
were excluded from the critical habitat designation. We also conclude 
in this final rule that this area is essential to the conservation of 
the silvery minnow because it likely serves as connecting corridors for 
fish movements between areas of sufficient flowing water (e.g., see 
Deacon and Minckley 1974; Eberle et al. 1993). Moreover, this reach is 
important because the additional loss of any habitat that is currently 
occupied could increase the likelihood of extinction (Hoagstrom and 
Brooks 2000, Service 1999).
    (39) Comment: Several commenters noted that the San Acacia reach 
has historically experienced prolonged periods of low or no flow, but 
the construction of reservoirs has actually benefitted the silvery 
minnow by allowing runoff to extend over a longer time period than was 
previously possible.
    Our Response: The construction and operation of reservoir dams has 
changed the natural flow regime of the river and thus may affect the 
survival of the Rio Grande silvery minnow. In the proposed rule, we 
acknowledged the historic periods of drying in the middle Rio Grande 
and suggested that reservoirs can facilitate management of water on the 
Rio Grande to avoid prolonged periods of low or no flow and provide 
sufficient flowing water during critical time periods, such as from May 
to October (Service 2001a, 2001b). Reservoirs and diversion dams have 
fragmented the middle Rio Grande and prevented silvery minnows from 
movement upstream after hatching

[[Page 8100]]

(Service 2001b; Dudley and Platania 2001; 2002a). Still, availability 
of flow is likely not the only factor affecting the silvery minnow 
(July 20, 1994; 59 FR 36988).
    (40) Comment: The designation of critical habitat within the middle 
Rio Grande will Federalize the water administration and usurp the 
powers of TX, NM, and Colorado to regulate their water.
    Our Response: Designation of critical habitat will not affect the 
authorities of TX, NM, and Colorado to regulate their water. In fact, 
critical habitat applies only to actions carried out, funded, or 
permitted by the Federal Government.
    (41) Comment: The proposed rule suggests that future section 7 
consultations regarding the critical habitat designation will be 
analyzed on a case-by-case basis and can provide for flexibility. 
However, one commenter was concerned that current consultations will 
affect the outcome of future consultations, resulting in overly 
restrictive measures.
    Our Response: Our regulations require that we use the best 
scientific and commercial data available for consultations (50 CFR 
402.14(d)). This information is used to update and analyze the effects 
of past and ongoing human and natural activities or events that have 
led up to the current status of the species and its habitat. One of the 
benefits of formal consultation is that we are required to provide an 
up-to-date biological status of the species or critical habitat (i.e., 
environmental baseline), which is used to evaluate a proposed action. 
Consequently, the status of the species or critical habitat influences 
the outcome of a particular consultation more than when that 
consultation is conducted.
    (42) Comment: If the bankfull width of the middle Rio Grande 
increases, would the additional area be considered critical habitat? It 
is not clear which lands within the critical habitat boundary are 
considered critical habitat.
    Our Response: Lands are considered critical habitat when they are 
within critical habitat boundaries, contain one or more of the primary 
constituent elements, and require special management and protection. In 
this case those boundaries are based in part on the bankfull stage, 
which can easily be determined by visual or physical indicators 
including: the top of the highest depositional features (e.g., point 
bars), staining of rocks, exposed root hairs, and other features 
(Rosgen 1996). Federal actions conducted in areas within or outside the 
boundary of the mapped critical habitat that do not contain any of the 
primary constituent elements would not trigger a section 7 consultation 
unless those activities may affect the silvery minnow or the primary 
constituent elements in the adjacent critical habitat (see ``Effect of 
Critical Habitat Designation'' section).
    (43) Comment: The Service cannot substitute the proposed 
conservation strategy for critical habitat; critical habitat triggers 
section 7 consultation, whereas the proposed conservation strategy 
offers no protection to the silvery minnow.
    Our Response: We believe that the benefits of excluding the middle 
Pecos River and lower Rio Grande outweigh the benefits of their 
inclusion as critical habitat (see ``Exclusions Under Section 4(b)(2) 
of the Act'' section below). We conclude that the exclusion of these 
areas is consistent with the Recovery Plan (Service 1999) and 
consistent with our regulations (50 CFR 424.19), and that the added 
management flexibility provided under section 10(j) will be beneficial 
to the conservation of the silvery minnow. Additionally, the adverse 
modification standard serves to preserve the status quo of critical 
habitat during section 7 consultations. But critical habitat, by 
itself, does not help to reestablish minnows into areas where they have 
been extirpated--a primary goal of the Recovery Plan for the minnow.
    (44) Comment: If the lateral boundary of critical habitat extends 
from the bankfull stage, how does one determine the point of bankfull 
stage when the Rio Grande is not at this stage?
    Our Response: Bankfull stage is the point at which the river 
overflows its lowest bank, which is the elevation at which flow can be 
carried by the main channel before spilling over into the floodplain. 
The bankfull stage is not defined by water, and can easily be 
determined by visual or physical indicators including: the top of the 
highest depositional features (e.g., point bars), staining of rocks, 
exposed root hairs, and other features (Rosgen 1996).
    (45) Comment: The designation for the silvery minnow and related 
documents are flawed and inaccurate, contain numerous errors, and make 
improper assumptions.
    Our Response: As previously discussed, section 4(b)(2) of the Act 
and 50 CFR 424.19 require us to consider the economic impact, and any 
other relevant impact, of specifying any particular area as critical 
habitat. We published our proposed designation of critical habitat for 
the silvery minnow in the Federal Register on June 6, 2002 (67 FR 
39206). The draft EIS and draft economic analysis of the proposed 
critical habitat designation were made available for review and public 
comment concurrently with the proposed rule during the public comment 
period. Based on the public comments received during the open comment 
period, a final EIS and final Economic Analysis of critical habitat for 
the silvery minnow were completed. These documents and this final rule 
addressed or took into consideration information and concerns raised 
through the comment period. Please refer to the final EIS and final 
Economic Analysis. Copies of both the draft and final EIS and the draft 
and final economic analysis are in the supporting record for this 
rulemaking and can be inspected or obtained by contacting the New 
Mexico Ecological Services Field Office (refer to the ADDRESSES section 
of this rule).
    (46) Comment: The draft economic analysis is not a full analysis. 
It is still an incremental analysis, and it is not in compliance with 
the recent Tenth Circuit Court ruling on the endangered southwestern 
willow flycatcher (Empidonax traillii extimus) critical habitat.
    Our Response: The economic analysis is a full analysis. Our 
standard best practice in economic analyses is to apply an approach 
that measures costs, benefits, and other impacts arising from a 
regulatory action against a baseline scenario of the world without the 
regulation. Guidelines on economic analyses, developed in accordance 
with the recommendations set forth in Executive Order 12866 
(``Regulatory Planning and Review''), for both the Office of Management 
and Budget and the Department of the Interior, note the appropriateness 
of the approach: ``The baseline is the state of the world that would 
exist without the proposed action. All costs and benefits that are 
included in the analysis should be incremental with respect to this 
baseline.'' When viewed in this way, the economic impacts of critical 
habitat designation involve evaluating the ``without critical habitat'' 
baseline versus the ``with critical habitat'' scenario. Impacts of a 
designation equal the difference, or the increment, between these two 
scenarios. Measured differences between the baseline and the scenario 
in which critical habitat is designated may include (but are not 
limited to) changes in land use, environmental quality, property 
values, or time and effort expended on consultations and other 
activities by Federal landowners, Federal action agencies, and, in some 
instances, State and local governments and/or private third parties. 
Incremental changes may

[[Page 8101]]

be either positive (benefits) or negative (costs).
    In New Mexico Cattle Growers Ass'n v. U.S. Fish and Wildlife 
Service, 248 F.3d 1277, however, the Tenth Circuit recently held that 
the baseline approach to economic analysis of critical habitat 
designations used by us for the southwestern willow flycatcher 
designation was ``not in accord with the language or intent of the 
ESA.'' In particular, the court was concerned that we had failed to 
analyze any economic impact that would result from the designation, 
because it took the position in the economic analysis that there was no 
economic impact from critical habitat that was incremental to, rather 
than merely co-extensive with, the economic impact of listing the 
species. We had therefore assigned all of the possible impacts of 
critical habitat designation to the listing of the species, without 
acknowledging any uncertainty in this conclusion or considering such 
potential impacts as transaction costs, reinitiations, or indirect 
costs. The court rejected the baseline approach incorporated in that 
designation.
    In our analysis, we addressed the Tenth Circuit's concern that we 
give meaning to the Act's requirement of considering the economic 
impacts of critical habitat designation by acknowledging the 
uncertainty of assigning certain post-designation economic impacts 
(particularly section 7 consultations) as having resulted from either 
the listing or the designation. We believe that for many species the 
designation of critical habitat has a relatively small economic impact, 
particularly in areas where consultations have been ongoing with 
respect to the species. This is because the majority of the 
consultations and associated project modifications, if any, already 
consider habitat impacts and, as a result, the process is not likely to 
change significantly as a result of the designation of critical 
habitat. Nevertheless, we recognize that the nationwide history of 
consultations on critical habitat is not broad, and, in any particular 
case, there may be considerable uncertainty whether an impact results 
from the critical habitat designation or the listing alone. We also 
understand that the public wants to know more about the kinds of costs 
section 7 consultations impose and frequently believes that critical 
habitat designation could require additional project modifications. 
Therefore, the final economic analysis incorporates two baselines. One 
addresses the impacts of critical habitat designation that may be 
``attributable co-extensively'' to the listing of the species. Because 
of the potential uncertainty about the benefits and economic costs 
resulting from critical habitat designations, we believe it is 
reasonable to estimate the upper bounds of the cost of project 
modifications on the basis of the benefits and economic costs of 
project modifications that would be required by consultation under the 
jeopardy standard. It is important to note that the inclusion of 
impacts attributable co-extensively to the listing does not convert the 
economic analysis into a tool to be considered in the context of a 
listing decision. As the court reaffirmed in the southwestern willow 
flycatcher decision, ``the ESA clearly bars economic considerations 
from having a seat at the table when the listing determination is being 
made.'' The other baseline, the lower boundary baseline, will be a more 
traditional rulemaking baseline. The economic analysis attempts to 
provide our best analysis of which of the effects of future section 7 
consultations actually result from the regulatory action under review 
(i.e., the critical habitat designation). These costs will in most 
cases be the costs of additional consultations, reinitiated 
consultations, and additional project modifications that would not have 
been required under the jeopardy standard alone, as well as costs 
resulting from uncertainty and perceptional impacts on markets. The 
final economic analysis provides a detailed study concerning the 
baseline and potential incremental effects of the designation of 
critical habitat for the silvery minnow, and we believe it is in 
compliance with the Tenth Circuit's decision in New Mexico Cattle 
Growers Ass'n v. U.S. Fish and Wildlife Service, 248 F.3d 1277.

Issue 3: Tribal and Pueblo Concerns

    (47) Comment: The Service is legally mandated to have Government-
to-Government consultations with affected Tribes and Pueblos. The 
designation will affect the trust assets of Tribes and Pueblos. Will 
the designation of critical habitat affect the Pueblos of Taos, San 
Juan, or the Jicarilla Apache Nation?
    Our Response: In accordance with Secretarial Order 3206, ``American 
Indian Tribal Rights, Federal-Tribal Trust Responsibilities, and the 
Endangered Species Act'' (June 5, 1997); the President's memorandum of 
April 29, 1994, ``Government-to-Government Relations with Native 
American Tribal Governments'' (May 4, 1994; 59 FR 22951); Executive 
Order 13175; and the Department of the Interior's requirement at 512 DM 
2, we recognize the need to consult with Federally recognized Indian 
Pueblos and Tribes on a Government-to-Government basis. Section 4(b)(2) 
of the Act requires us to gather information regarding the designation 
of critical habitat and the effects thereof from all relevant sources, 
including Indian Pueblos and Tribes.
    We were available to confer with the affected Indian Pueblos and 
Tribes during the comment period for this proposed rule. Recognizing 
our Federal trust responsibility, we met with the following Pueblos and 
Tribes (some meetings were to provide technical assistance and are not 
considered Government-to-Government consultations): Jicarilla Apache 
Nation (October 22, 2001; January 9 and 25, 2002; March 7, 2002), San 
Juan (December 11, 2001; February 25, 2002; September 6, 2002), Isleta 
(July 25, 2002; August 8 20, 2002), Sandia (October 22, 2001; February 
12, 2002; September 25, 2002), Santa Ana (December 11, 2001; July 9 and 
10, 2002; August 2 and 6, 2002; September 13, 2002), Santo Domingo 
(August 8, 2002), and Taos Pueblos (April 2, 2002; September 11, 2002; 
October 23, 2002) to discuss how they might be affected by the 
designation of critical habitat or other issues related to the Act. We 
provided technical assistance to Santo Domingo, Santa Ana, Sandia, and 
Isleta Pueblos in the development of their management plans (see 
``Relationship of Critical Habitat to Pueblo Lands under Section 
3(5)(A) and Exclusions Under Section 4(b)(2)'' section of this rule 
below).
    The designation of critical habitat is not anticipated to impact 
Indian Trust Assets, which are legal interests in assets held in trust 
by the United States Government for Tribes and Pueblos. Water rights 
are considered an Indian Trust Asset. For an impact to occur, the 
designation of critical habitat would need to diminish the Tribe's 
access to or the value of any Indian Trust Asset. For example, the BOR 
recently indicated that the six middle Rio Grande Pueblos would receive 
prior and paramount water deliveries through November 15, 2002, and 
that future deliveries of prior and paramount water for the six middle 
Rio Grande Pueblos will also be ensured. Prior and paramount water 
deliveries are not dependent on, and are not expected to affect, 
supplemental water deliveries for the silvery minnow (BOR 2002). We 
also do not believe that other Tribes or Pueblos (e.g., Taos and San 
Juan Pueblos, Jicarilla Apache Nation) outside of the critical habitat 
designation will be affected. We believe that the consultation history 
of the silvery minnow demonstrates that previous section 7 
consultations have not affected or impaired Indian Pueblo

[[Page 8102]]

and Tribal trust resources within the area we are designating as 
critical habitat (e.g., see Service 2001b). During consultation, 
measures taken to avoid destruction or adverse modification of critical 
habitat will likely be similar if not identical to what is currently 
required to avoid jeopardizing the silvery minnow. Consequently, we do 
not believe that critical habitat will result in requirements during 
consultation, and do not believe critical habitat will affect Indian 
Trust Assets.
    (48) Comment: The Service completely omits Pueblos from the 
analysis under the Regulatory Flexibility Act.
    Our Response: We are certifying that this final rule will not have 
a significant effect on a substantial number of small entities, 
including Indian Tribes and Pueblos (see ``Required Determinations'' 
section below).
    (49) Comment: Critical habitat will require the maintenance of 
river flows which will adversely affect Pueblos by limiting the amount 
of water available. Pueblos may have substantial unused water rights. 
If critical habitat limits depletions, the designation would 
disproportionately affect Pueblos.
    Our Response: We do not anticipate that the designation of critical 
habitat will alter the administration of the supplemental water 
program. Thus, delivery of water to middle Rio Grande contractors and 
Pueblos is ensured (BOR 2001c). Environmental justice-related impacts 
of preferred alternatives for critical habitat designation are 
discussed in Chapter 4 of the EIS. Nothing in the final rule or the EIS 
is intended to preclude new depletions resulting from the exercise of 
senior Indian water rights. In addition, please see response to comment 
48 for information related to this particular issue.

Issue 4: Other Relevant Issues

    (50) Comment: The Service has continued to ignore the economic 
consequences of designating critical habitat for the silvery minnow on 
the Pecos River.
    Our Response: The Pecos River is not designated as critical habitat 
for the silvery minnow.
    (51) Comment: In the Economic Analysis, why is it assumed that all 
the water required to meet supplemental flows will all come from NM 
agriculture? The Rio Grande flows through three states, so why will the 
burden of ensuring the survival of the silvery minnow be placed upon 
the water users in the middle Rio Grande? Are interstate water rights 
transfers (i.e., sale or lease) possible under existing Federal or 
State law?
    Our Response: The Economic Analysis assumed that water resources in 
NM are limited, which is demonstrated by an active market in which 
water rights move between willing buyers and sellers within the 
confines of State and Federal regulations. From 1976 to 2000, the 
purchasers of water rights in the middle Rio Grande were generally 
municipalities (61 percent of purchasers); however, other sectors 
participate as buyers in this market as well. During the same time 
frame, the sellers of water rights in the middle Rio Grande were 
primarily agriculture (90 percent of sellers) reflecting the fact that 
the majority of the water rights (as measured by total volume of water 
reflected in these rights) are currently held in the agriculture 
sector. Given these data, it was assumed that any water provided to the 
silvery minnow by supplementing present water flow conditions would 
come from currently held irrigation water rights because these tend to 
have greater flexibility than water rights for municipal or commercial 
uses. Thus, the economic analysis focused on the area within the middle 
Rio Grande for providing supplemental water, and did not consider 
interstate transfers of water. In general, our economic analyses 
consider the impacts within the geographic area being proposed as 
critical habitat. For example, in this case the economic analysis 
considered the area proposed as critical habitat in the middle Rio 
Grande, as well as the other two areas found to be essential to the 
conservation of the minnow (i.e., middle Pecos River and Lower Rio 
Grande). While interstate water rights transfers (i.e., sale or lease) 
may be possible under existing Federal or State law, we concluded that 
such transfers were beyond the scope of our economic analysis.
    (52) Comment: The Economic Analysis severely underestimates the 
costs associated with providing 40,000 af of supplemental water because 
it did not estimate transaction costs associated with the purchase or 
lease of water rights.
    Our Response: Easter et al. (1999) found that transaction costs 
associated with purchase or lease of water rights must be kept low for 
an effective water market. For example, they estimated that transaction 
costs range from about $17 to $190 per af. Another example indicates 
that a 10 percent commission is common for completing the sale or lease 
of a water right in NM (Turner 2002a; http://www.waterbank.com/Agreements/Agency%20Agreement.htm). Based on these and other data, the 
final Economic Analysis estimates that the average transaction cost is 
likely $333 and $183 for the Rio Grande and Pecos, respectively. 
Consequently, the estimated transaction costs would be approximately 7 
to 10 percent of the total price of an acre-foot. These estimates do 
not change our required determinations below.
    (53) Comment: The Service should have used the Upper Rio Grande 
Water Operations Model (URGWOM) to determine the amount of supplemental 
water to meet the target flow of 50 cfs at the San Marcial Floodway 
gage. The Service did not use the best scientific and commercial data 
available because you failed to engage the State of New Mexico and use 
their expertise, data, and models.
    Our Response: On September 5, 2001, we invited the NMISC to 
participate in the development of the EIS as a cooperating agency. On 
October 3, 2001, the NMISC accepted our invitation. On April 9, 2002, 
the Service requested the expert review of the preliminary 
predecisional draft EIS and preliminary predecisional draft economic 
analysis from the NMISC, as a cooperating agency. We requested the 
review because the NMISC has jurisdiction by law or special expertise 
over water resources and environmental impacts involved with the 
Service's action of designating critical habitat. We specifically 
requested that the review focus on the accuracy of information and 
analyses as described in the draft documents. On April 25, 2002, the 
NMISC requested additional information from the Service and our 
contractors. During the open comment period for the proposed rule, we 
met on July 2 and 22, 2002, with the NMISC to further coordinate the 
designation of critical habitat and clarify the additional information 
requested. Nevertheless, we could not rely on data from URGWOM to 
develop the final rule because the information has yet to be submitted.
    A focal point of discussions with the NMISC was the use of URGWOM 
for estimating the amount of supplemental water needed to maintain 
flows in the middle Rio Grande. During these meetings and in a July 16, 
2002, letter, we indicated that on the basis of discussions between our 
contractor and the NMISC, and according to the May 9, 2002, notes from 
the URGWOM Steering Committee meeting, we understood that URGWOM was 
still being calibrated and validated. It was also our understanding 
that URGWOM and the relevant input and output data have not been tested 
by all the cooperating agencies for the

[[Page 8103]]

Upper Rio Grande Water Operations Review EIS and would not be made 
publicly available until this occurs. As noted in the April 11, and 
September 12, 2002, notes from the URGWOM Steering Committee meetings: 
(1) The consensus of the Steering Committee members was that the latest 
version of URGWOM should not be released until it has been tested and 
is ready for public use; (2) the data and results for various model 
runs were not totally successful, but furthered the model debugging, 
testing, and evaluation; (3) the middle Rio Grande valley water 
depletions are modeled too high; (4) the water planning model is 
currently simplistic and rough; and (5) water operations modeling is 
still undergoing troubleshooting, repairs, and enhancements. Thus, we 
conclude that URGWOM is not available for use in the economic analysis.
    Nevertheless, during the July 22, 2002, meeting with the NMISC, it 
was agreed that the NMISC would run URGWOM and provide detailed 
comments, data, output, and interpretation to us during the open 
comment period on this and other relevant analyses. We also requested 
that the NMISC assist us in determining the economic costs of providing 
water to meet Rio Grande Compact delivery obligations separate from the 
economic costs of leaving water in the river for the silvery minnow. 
The NMISC indicated in its October 2, 2002, comments on the proposed 
critical habitat designation that the data and analyses were nearly 
complete and a report interpreting the results would be submitted in 
November 2002. Additional comments or data were not submitted. If 
additional comments or data had been submitted after October 2, 2002, 
we would not have considered them in the development of this final 
rule, the economic analysis, or the EIS because the data, analyses, and 
report would not have been submitted during the open comment period, 
and other parties would not have had the full opportunity to review and 
comment on the material.
    Section 4(b)(2) of the Act states critical habitat shall be 
designated on the basis of the best scientific data available. We must 
make this determination on the basis of the information available at 
this time, and we are not allowed to delay our decision until further 
information is submitted. Therefore, we conclude the current 
hydrological model used in the economic analysis is the best scientific 
information available at this time, as required by the Act.
    (54) Comment: The Economic Analysis appears to underestimate the 
amount of supplemental water that is required to maintain flows 
specified by the biological opinion on the middle Rio Grande.
    Our Response: From our experience, it is nearly impossible to 
guarantee continuous flow in the middle Rio Grande at all times of the 
year, regardless of the extremity of conditions. As a result, our 
analysis calculates the annual deficit of water below the required 
minimum flow in the 95th percentile and the 50th percentile worst-case 
(e.g., driest) year. This calculation results in an average annual 
deficit of 40,427 af/year in the middle Rio Grande. This estimate of 
supplemental water is within the range of other estimates of 
supplemental water required to maintain instream flow in the middle Rio 
Grande. Since 1996, the BOR has leased water each year to maintain 
instream flow during this dry period. In 2001, 22,000 af of 
supplemental water, from the conservation water agreement, was released 
and was sufficient to meet the supplemental flow requirements outlined 
in the June 29, 2001, biological opinion (J. Smith, pers. comm., 2002). 
In addition, Balleau Groundwater, Inc. (1999) estimated that it would 
require 52,600 af of water released from Cochiti to maintain a flow of 
200 cfs at San Acacia in an average year. Therefore, we believe our 
estimate of approximately 40,000 af of supplemental water is accurate.
    (55) Comment: The Service's analyses do not take into account 
upstream storage that would be needed to provide for supplemental 
flows, nor did the Service address storage of native water when storage 
is restricted in upstream reservoirs (e.g., see Rio Grande Compact, 
Article VII).
    Our Response: The hydrologic model used in the economic analysis 
did not attempt to model the location of water used to supplement 
instream flow, but rather provided the amount of supplementary water 
needed at the San Acacia (middle Rio Grande) and Acme (middle Pecos 
River) gages. We did not identify sources of supplemental water (e.g., 
storage) within this designation, because these sources can vary 
annually. Moreover, the Federal agencies have discretion on selecting 
specific sources and storage of supplemental water (BOR 2001c; Corps 
2001). The amount of supplemental flows will be dependent upon the 
environmental baseline of the silvery minnow, the proposed action by 
the Federal agency, and those discretionary actions that are part of 
the consultation.
    (56) Comment: Future supplemental water will not be available in 
the middle Rio Grande as it was from 1996 to 2002.
    Our Response: As with all biological opinions, if the Federal 
action agency, (i.e., the BOR in the June 29, 2001, biological opinion) 
cannot meet the measures described in the biological opinion that must 
be undertaken, reinitiation of formal consultation is required. In the 
middle Rio Grande, if supplemental water is not available to meet 
target flows contained in a biological opinion, then reinitiation of 
consultation would be required. Reinitiation of consultation has no 
bearing on the designation of critical habitat for the silvery minnow.
    (57) Comment: The designation will steal water from an already 
drought-stricken area. Critical habitat will devastate the farming 
culture.
    Our Response: The maintenance of river flows has been implemented 
through BOR's voluntary supplemental water program. This program is 
being implemented within the existing water rights framework, including 
Federal Indian water rights, San Juan-Chama contract rights, and state 
law water rights administered by the State of New Mexico. Supplemental 
flows to avoid destruction or adverse modification of critical habitat 
will likely be similar if not identical to what is currently required 
to avoid jeopardizing the species.
    During the 2000 irrigation season, most of the supplemental water 
used to support the silvery minnow was provided through BOR leases of 
San Juan-Chama Project water from the City of Albuquerque. The City in 
turn provided that water to the MRGCD to finish the irrigation season, 
while allowing native Rio Grande flows to remain in the river without 
diversion. Moreover, in June 2002, the City of Albuquerque signed two 
agreements to provide 40,000 af of water to the BOR for supplemental 
flows for the silvery minnow and an additional 70,000 af of water to 
extend the MRGCD irrigation season from June to September 2002.
    The BOR supplemental water program has been implemented on a year-
to-year basis since 1997. During this period, no irrigation water has 
been used to augment river flows without being replaced (BOR 2001c). 
For example, the water that was leased from San Juan-Chama contractors 
and released during 2000 was used by MRGCD for irrigation and was 
exchanged for an equivalent amount of native Rio Grande water to 
provide supplemental flows for the silvery minnow. We believe that 
these types of collaborative actions will continue and do not 
anticipate that the

[[Page 8104]]

amount of supplemental instream flow, required by past section 7 
consultations (e.g., Service 2001b), will increase because an area is 
designated as critical habitat.
    (58) Comment: The Service should analyze the impacts on 
groundwater, urban development, and operation of canals and other 
irrigation structures.
    Our Response: The EIS analyzes impacts on water rights and 
management, land ownership and use, social and economic impacts, and a 
variety of other environmental consequences.
    (59) Comment: The Service should consider the positive impact of 
critical habitat designation in the region's economy.
    Our Response: The potential benefits of critical habitat are 
described in the economic analysis and EIS.
    (60) Comment: It is currently impossible with the natural flow 
regime (i.e., after all managed uses of water are curtailed) to 
maintain the primary constituent elements related to water flow. The 
primary constituent element that indicates conditions ``do not increase 
prolonged periods of low or no flow'' presume a baseline is known.
    Our Response: Critical habitat is designated on the basis of 
existing conditions within each of the river reaches. We acknowledge 
that some of these areas have the potential for no to low flow during 
certain seasons or years. This primary constituent element provides 
water of sufficient flows to reduce the formation of isolated pools, 
and is essential to the conservation of the silvery minnow because the 
species cannot withstand permanent drying of long stretches of river. 
In addition, please see response to comment 35 for information related 
to this particular issue.
    (61) Comment: There is not enough information known about the 
silvery minnow or about the impacts of the designation to perform the 
required analyses.
    Our Response: This final determination constitutes our best 
assessment of areas needed for the conservation of the silvery minnow. 
We must make this determination on the basis of the information 
available at this time, and we may not delay our decision until more 
information about the species and its habitat are available. Southwest 
Center for Biological Diversity v. Babbitt, 215 F.3d 58 (D.C. Cir. 
2000).
    (62) Comment: The Service concludes that low or no-flow conditions 
have become more prevalent in the last few decades. The hydrological 
data demonstrate that this is not true. These unfounded claims indicate 
that a thorough hydrologic analysis of the middle Rio Grande should be 
completed using hydrological variability techniques (e.g., Richter et 
al. 1997).
    Our Response: We have revised the ``Background'' section of this 
final rule. We are participating in the Upper Rio Grande Basin Water 
Operations Review and EIS with the Joint Lead Agencies and other 
cooperators, including the Corps, BOR, and the NMISC, to 
comprehensively review the water operations activities that are 
conducted under the existing authorities in the Rio Grande Basin above 
Fort Quitman, TX. Hydrological variability techniques (e.g., Richter et 
al. 1997) can guide river managers to define and adopt interim 
management targets before conclusive long-term research results are 
available. The Federal agencies have discretion when selecting specific 
river management targets and activities (e.g., sources and storage of 
supplemental water (BOR 2001c; Corps 2001)). Consequently, hydrological 
variability techniques could be applied to river management targets and 
activities at the discretion of the Federal agencies, but are beyond 
the scope of this designation.
    (63) Comment: One commenter questioned why, although approximately 
200,000 af of water were released in the summer of 2000 to save the 
silvery minnow from extinction, the species suffered one of its most 
significant declines during this artificially wet period. NM and other 
signatories of the Rio Grande Compact cannot afford this waste of 
water.
    Our Response: In the spring of 2000, as a result of court-ordered 
mediation (Minnow v. Keys, Civ. No. 99-1230 JP/KBM-ACE), BOR, through 
voluntary leases and repayment agreements, and in cooperation with 
other entities, provided 168,000 af of water to the Rio Grande for the 
silvery minnow and for irrigation purposes during the year 2000. Data 
from silvery minnow population monitoring studies in 2001 indicated a 
slight increase of the population in the Angostura, Isleta, and San 
Acacia Reaches (Dudley and Platania 2001). Without efforts to maintain 
at least some flow in the Rio Grande in 2000, it is likely that the 
silvery minnow might have been extirpated from the middle Rio Grande 
(Dudley and Platania 2001). It is also important to note that, at least 
partially as a result of these supplemental flows, NM realized a credit 
of 100,000 af toward its current and future delivery obligations to TX 
under the Rio Grande Compact (BOR 2001c).
    (64) Comment: Because of the silvery minnow, the Service has not 
allowed the BOR to maintain a channel through the delta area north of 
Elephant Butte Reservoir.
    Our Response: On May 8, 2000, we received a biological assessment 
from BOR concerning the creation of a temporary channel through the 
upstream delta of Elephant Butte Reservoir. BOR proposed to implement 
several conservation measures-these were included and described in 
their biological assessment as part of the project. On August 4, 2000, 
we completed consultation by concurring with BOR's determination that 
the project ``may affect but is not likely to adversely affect'' the 
silvery minnow or its designated critical habitat, that it ``may affect 
but is not likely to adversely affect'' the southwestern willow 
flycatcher, and that it will have ``no effect'' on the bald eagle. 
During September 2000 and April 2001, BOR provided supplementary 
information and clarifications on the project activities. No additional 
effects were anticipated and it is our understanding that BOR is 
proceeding with the construction of the temporary channel in full 
compliance with its responsibilities under the Act. In a letter dated 
August 30, 2002, from the Service's New Mexico Ecological Services 
Field Office to the New Mexico Office of the State Engineer, we 
reiterated that environmental compliance with the Act had been 
achieved. In the letter, we specifically asked whether the State 
Engineer believed that further environmental clearances were required 
for the completion of the temporary channel. We did not receive a 
response to the August 30, 2002, letter.
    (65) Comment: Many environmental groups are using the silvery 
minnow to further their agendas of stopping growth and development.
    Our Response: The recovery of the silvery minnow follows our 
cooperative policy on recovery plan participation, a policy intended to 
involve stakeholders in recovery planning (July 1, 1994; 59 FR 34272). 
Numerous individuals, agencies, environmental groups, and affected 
parties were involved in the development of the Recovery Plan or 
otherwise provided assistance and review (Service 1999). We believe 
this stakeholder involvement will minimize the social and economic 
impacts that could be associated with recovery of this endangered 
species.
    Section 4(a)(3) of the Act requires that the Secretary, to the 
maximum extent prudent and determinable, designate critical habitat at 
the time a species is

[[Page 8105]]

listed as endangered or threatened. As noted under the ``Background 
Section'' above, when the silvery minnow was listed as endangered in 
1994, we found that critical habitat was not determinable. 
Subsequently, we were ordered to publish a final determination 
regarding critical habitat for the silvery minnow, Forest Guardians v. 
Babbitt, Civ. No. 97-0453 JC/DIS. On July 6, 1999, we published a final 
designation of critical habitat for the silvery minnow (64 FR 36274), 
pursuant to the court order.
    Critical habitat will affect private, State, or Tribal activities 
when Federal funding, permitting, or authorization is involved. If 
there is Federal involvement, consultation will be completed within the 
statutory time frames. The process of section 7 consultation does not 
stop growth or development.
    (66) Comment: Your last economic analysis found that there would be 
no impacts associated with the designation of critical habitat for the 
silvery minnow.
    Our Response: We were required to prepare a new critical habitat 
designation under the court order from the United States District Court 
for the District of New Mexico, in Middle Rio Grande Conservancy 
District v. Babbitt, 206 F. Supp. 2d 1156 (D.N.M. 2000). We prepared a 
new economic analysis, a draft EIS, and a new proposed rule pursuant to 
that court order. A new economic analysis was completed to address this 
revised final designation, the previous economic analysis is not 
reflective of this designation or our current approach for analyzing 
economic impacts.
    (67) Comment: The economic analysis only considered the middle Rio 
Grande as an entire unit and did not evaluate economic impacts to 
different areas within the middle Rio Grande. An economic analysis that 
does not take local land and water use into account does not disclose 
the full economic costs of the designation and is of no benefit to the 
Service or the public.
    Our Response: The economic analysis includes specific analyses 
within the area designated as critical in the middle Rio Grande by 
estimating the cost of designating critical habitat in each of the five 
reaches. The analysis utilized all information provided by the Federal, 
State, local, and Tribal respondents operating in the area, including 
models created by and technical assistance from the New Mexico State 
University Agricultural Extension Service. Information concerning the 
local and regional economy was analyzed to conclude that there would 
not be significant economic impacts associated with the designation of 
critical habitat for the silvery minnow (see also the ``Economic 
Analysis'' section of this rule).
    (68) Comment: The draft economic analysis uses alfalfa as the basis 
for calculating the cost of forgone production and secondary economic 
impacts. The estimated economic impacts were likely underestimated 
because alfalfa makes up about 56 percent of the agricultural crops in 
the middle Rio Grande. The costs of forgone production on the other 44 
percent of agricultural crops would likely be higher, since alfalfa is 
a relatively low-value, high-water-consuming crop.
    Our Response: Based on interviews with local crop scientists and 
because of the dominant status, annual planting cycle, and relatively 
high water requirements of alfalfa, the economic analysis assumes that 
acres retired from planting will be those devoted to the alfalfa crop. 
However, the economic analysis indicated that this assumption is likely 
to be conservative and to overstate effects on the regional economy 
when compared with modeling reductions in water available to other 
crops. A second calculation using a reduction in hay production is 
included in the final economic analysis to provide comparison. Modeling 
the same reductions in water available to the second most prevalent 
crop in each study area (pasture hay for the middle Rio Grande and 
cotton for the Pecos) produces a total value of forgone production that 
is 3 percent less than that produced by modeling removals from alfalfa. 
Given that 90 percent of the irrigated acreage in the middle Rio Grande 
study area and over 75 percent of the irrigated acreage in the Pecos 
study area are devoted to the two dominant crops, it is likely that 
water removed from irrigation would come from one of these two crops, 
validating the assumptions set forth in the economic analysis.
    (69) Comment: The draft economic analysis does not consider that NM 
has had an active water market for years and many farmers have not 
chosen to sell their water rights. Consequently, the acquisition of 
water to meet supplemental flows may not be available.
    Our Response: Under New Mexico State law, users of water must hold 
a water right. Such rights are treated as property rights, and are 
traded in a market. Since a competitive market exists for water rights 
in NM, it is assumed that the price of these rights represents the 
expected economic benefit of water made available by these rights, in 
its highest and best use. That is, in paying for water rights, buyers 
are making clear the implicit value of the water to them. The economic 
analysis concluded that (1) there is an active market in NM to move 
water to uses other than the original use; (2) there are multiple 
buyers and sellers of water rights; and (3) the price of water rights 
can be predicted from expected underlying economic factors.
    Studies and historic and current data indicate that ``water flows 
uphill toward money'' (Brookshire et al. 2002; Hall 2002). In other 
words, water will move toward the highest valued use in accordance with 
the economy. For example, 90 percent of all water rights transferred 
(i.e., leased or sold) in the middle Rio Grande from 1976 to 2000 were 
previously held by irrigation (Brookshire et al. 2002). Consequently, 
we believe that the voluntary acquisition of water to meet supplemental 
flows will be available.
    (70) Comment: The economic analysis underestimates the farmland 
removed from production to provide for supplemental flows.
    Our Response: The economic analysis used models created by the New 
Mexico Cooperative Extension Service and NM agricultural statistics 
from the New Mexico Agricultural Statistics Service to estimate costs 
and returns for the State's farming industry in 2001. The commenter did 
not provide any data for us to consider and did not explain why he or 
she believes our estimates to be inadequate.
    (71) Comment: Agricultural production in the middle Rio Grande 
valley is on a scale that does not allow comparison to agriculture 
elsewhere in the United States. Consequently, the values of agriculture 
are as much social and cultural as they are economic. The Service 
should consider these values before finalizing the designation.
    Our Response: The economic analysis estimated: (1) The opportunity 
cost of water needed to supplement instream flow; (2) direct, indirect, 
and induced economic effects resulting from the resulting changes in 
the use of water, including cultural and secondary impacts on water 
sellers and communities; and (3) costs of section 7 consultations. The 
EIS also analyzed the social and economic impacts, impacts on land use, 
and impacts on cultural resources. Please refer to the economic 
analysis and EIS for a complete analysis of these impacts.
    (72) Comment: The economic analysis assumed that the market for 
water rights may not result in actual delivery of ``wet water'' (i.e., 
water in the river) once the middle Rio Grande is adjudicated.

[[Page 8106]]

    Our Response: Water rights in the middle Rio Grande are not 
adjudicated and much of the water uses are not metered (Whitney et al. 
1996). Adjudicating water rights (i.e., a judicial determination and 
definition of water rights within a river system that quantifies and 
establishes the legal right to use water) in the middle Rio Grande 
would, in conjunction with a metering program, allow for improved 
administration of water rights and improved water management (Whitney 
et al. 1996). However, an adjudication may not be completed for the 
middle Rio Grande in the foreseeable future.
    The State Engineer of New Mexico has indicated that as water 
markets begin to develop in the state, there will be a natural tendency 
to attempt to transfer paper water rights (New Mexico Office of the 
State Engineer 2001). The State Engineer is charged with water rights 
adjudications (New Mexico Office of the State Engineer 2001). The 
existing adjudication system is being examined to allow the entire 
State to be adjudicated (New Mexico Office of the State Engineer 2001). 
Moreover, the State Engineer of New Mexico has three criteria that must 
be met in order for state law water rights to be transferred: (1) The 
right must be valid, with a valid priority date; (2) the water must be 
put to beneficial use; and (3) the transferred water right must not 
impair the rights of others, including compact deliveries. For these 
reasons, we believe that the sale or lease of water rights will result 
in the delivery of ``wet water.''
    (73) Comment: The prevailing price of water rights in the middle 
Rio Grande will substantially increase when more than 40,000 af water 
rights are sold and removed from the water rights market.
    Our Response: The price of water rights is significantly affected 
by the type of buyer (e.g., municipal, private, Federal/State) and has 
increased in NM over the last several decades (Brookshire et al. 1999). 
However, water markets remain highly localized, with significantly 
different prices in each market. Nevertheless, the value used in the 
economic analysis reflects the current price of water rights resulting 
from the voluntary acquisition of supplemental water. We expect these 
types of voluntary programs to continue, and do not anticipate that the 
amount of supplemental water (i.e., demand) in previous consultations 
(e.g., Service 2001b) will increase because critical habitat is 
designated. In addition, please see response to comment 57 for 
information related to this particular issue.
    (74) Comment: The economic analysis does not explain why a 20-year 
time period was selected.
    Our Response: The economic analysis stated that activities 
occurring greater than 20 years in the future are difficult to predict, 
and the outcomes of such activities are even more uncertain. The 20-
year time horizon was selected because population forecasts as well as 
local and regional planning documents use similar time horizons.
    (75) Comment: The economic analysis does not explicitly address 
whether the benefits of excluding a particular reach outweigh the 
benefits of including the reach as critical habitat.
    Our Response: We use the economic analysis and other relevant 
information to conduct analyses under section 4(b)(2) of the Act. If 
relevant to a particular critical habitat designation, these 
considerations are included in the final rule (50 CFR 424.19). For a 
detailed discussion, see the ``Exclusions Under Section 4(b)(2) of the 
Act'' and ``Relationship of Critical Habitat to Pueblo Lands under 
Section 3(5)(A) and Exclusions Under Section 4(b)(2)'' sections below.

Summary of Changes From the Proposed Rule

    In the development of this final designation of critical habitat 
for the silvery minnow we made several changes to the proposed critical 
habitat designation based on our review of public comments received on 
the proposed designation, the draft economic analysis, and the draft 
EIS and further evaluation of lands proposed as critical habitat. As 
discussed in the ``Relationship of Critical Habitat to Pueblo Lands 
Under Section 3(5)(A) and Exclusions Under Section 4(b)(2)'' section of 
this final rule, we evaluated the lands proposed as critical habitat 
for the Pueblos of Santo Domingo, Santa Ana, Sandia, and Isleta. 
Because each of these Pueblos submitted management plans that provide 
for special management considerations or protections for the silvery 
minnow and because of other relevant issues, (see ``Relationship of 
Critical Habitat to Pueblo Lands Under Section 3(5)(A) and Exclusions 
Under Section 4(b)(2)'' section below), these lands were not included 
in the final critical habitat designation.
    The downstream boundary of critical habitat differs from that 
described in the proposed rule. In the proposal, the boundary was 
Elephant Butte Reservoir Dam, with the reservoir specifically excluded 
by definition (June 6, 2002; 67 FR 39206). However, in this final rule, 
we selected the utility line crossing the Rio Grande with UTM 
coordinates of UTM Zone 13: 311474 E, 3719722 N, just east of the 
Bosque Well demarcated on USGS Paraje Well 7.5 minute quadrangle 
(1980). This downstream boundary of critical habitat was selected 
because it is a permanent identified landmark that is found on a 
standard topographic map. The area below this boundary (i.e., from the 
utility line downstream to Elephant Butte Reservoir Dam) has the 
potential to be inundated by the reservoir and may not provide those 
physical or biological features essential to the conservation of the 
species and is therefore not designated as critical habitat.
    During the open comment period, the BOR provided GIS maps that 
identified the utility line crossing the Rio Grande with UTM 
coordinates of UTM Zone 13: 311474 E, 3719722 N, just east of the 
Bosque Well demarcated on USGS Paraje Well 7.5 minute quadrangle (1980) 
(M. Porter, BOR, pers. comm., 2002). Consequently, we revised the 
boundary for the designation because we find that the area downstream 
of the utility line is not essential to the conservation of the silvery 
minnow and we believe that the boundary, as originally proposed, was 
confusing as evidenced by many commenters, including the Elephant Butte 
Irrigation District, the NMISC, and others.
    We further reviewed existing information (Platania and Dudley 
2001a) to determine if the area from the designated critical habitat 
boundary to the headwaters of Elephant Butte Reservoir is essential to 
the conservation of the silvery minnow. For example, the location for 
the silvery minnow spawning study (Platania and Dudley 2000, 2001a) is 
just downstream of the critical habitat boundary. The study location 
was selected to maximize the potential number of silvery minnow eggs 
collected by rescuing those eggs destined to drift into Elephant Butte 
Reservoir. Currently, if silvery minnow spawn in the area from the 
designated critical habitat boundary to the headwaters of Elephant 
Butte Reservoir, the floating eggs would enter the reservoir in just a 
few hours. Once the eggs and larvae enter the reservoir, they would be 
subjected to predation (Platania and Dudley 2001a). We find that 
silvery minnow eggs and larvae in this reach contribute little to the 
survival or recovery of the species. Consequently, the area from the 
designated critical habitat boundary to the headwaters of Elephant 
Butte Reservoir is not essential to the conservation of the silvery 
minnow. Because of these reasons, we also believe that the exclusion of 
this area

[[Page 8107]]

from the designated critical habitat will not lead to the extinction of 
the species. It should be noted that the Service, in collaboration with 
other State and Federal agencies, rescues silvery minnow eggs in the 
lower San Acacia Reach for use in captive propagation and subsequent 
augmentation of the silvery minnow in the middle Rio Grande.

Exclusions Under Section 4(b)(2) of the Act

    Section 4(b)(2) of the Act requires us to base critical habitat 
designations on the best scientific and commercial data available, 
after taking into consideration the economic and any other relevant 
impact of specifying any particular area as critical habitat. We may 
exclude areas from a critical habitat designation when the benefits of 
exclusion outweigh the benefits of designation, provided the exclusion 
will not result in the extinction of the species. Our analysis of the 
following two areas: (1) The river reach in the middle Pecos River, NM, 
from Sumner Dam to Brantley Dam in De Baca, Chaves, and Eddy Counties, 
NM; and (2) the river reach in the lower Rio Grande in Big Bend 
National Park downstream of the National Park boundary to the Terrell/
Val Verde County line, TX, concludes that the benefits of excluding 
these areas from the designation of critical habitat outweigh the 
benefits of including them. Therefore, we are not designating these 
areas as critical habitat.

(1) Benefits of Inclusion

    The benefits of inclusion of the river reach in the middle Pecos 
River, NM, from Sumner Dam to Brantley Dam in De Baca, Chaves, and Eddy 
Counties, NM, would result from the requirement under section 7 of the 
Act that Federal agencies consult with us to ensure that any proposed 
actions do not destroy or adversely modify critical habitat. 
Historically, no consultations have occurred on the Pecos River for the 
silvery minnow since the area is not occupied by the species. However, 
while critical habitat designation could provide some benefit to the 
silvery minnow, in fact, consultations are already occurring for 
another listed fish with similar habitat requirements. The Pecos 
bluntnose shiner (Notropis simus pecosensis) was federally listed in 
1987 and portions of the Pecos River are designated as critical habitat 
for the Pecos bluntnose shiner (February 20, 1987; 52 FR 5295). As 
stated in the ``Criteria for Identifying Critical Habitat'' section of 
this rule, these fish species belong to the same guild of broadcast 
spawners with semibuoyant eggs and also spawn during high flow events 
with eggs and larvae being distributed downstream (Bestgen et al. 
1989). Therefore, flow regime operations in this reach that benefit the 
Pecos bluntnose shiner also provide benefits to silvery minnow habitat. 
We also believe that the primary constituent elements for the Pecos 
bluntnose shiner critical habitat are compatible with the primary 
constituent elements for the silvery minnow (see ``Criteria for 
Identifying Critical Habitat'' section below). Thus, we find that 
little additional benefit through section 7 consultation would occur as 
a result of the overlap between habitat suitable for the silvery minnow 
and the Pecos bluntnose shiner listing and critical habitat 
designation.
    In Sierra Club v. Fish and Wildlife Service, 245 F.3d 434 (5th Cir. 
2001), the Fifth Circuit Court of Appeals stated that the 
identification of habitat essential to the conservation of the species 
can provide informational benefits to the public, State and local 
governments, scientific organizations, and Federal agencies. The court 
also noted that heightened public awareness of the plight of listed 
species and their habitats may facilitate conservation efforts. We 
agree with these findings; however, we believe that there would be 
little additional informational benefit gained from including the 
middle Pecos River because the final rule identifies all areas that are 
essential to the conservation of the silvery minnow, regardless of 
whether all of these areas are included in the regulatory designation. 
Consequently, we believe that the informational benefits will be 
provided to the middle Pecos River, even though this reach is not 
designated as critical habitat.
    The economic analysis recognizes that while consultations regarding 
the Pecos River will occur without a silvery minnow critical habitat 
designation, those consultations would not consider the silvery minnow. 
However, because of the similar life history requirements of these 
species, we do not anticipate that the outcomes of such consultations 
would be altered. We recognize, as does the economic analysis, that the 
middle Pecos River area (as described above) covers about twice the 
length of the area designated for the Pecos bluntnose shiner. 
Historically, two formal consultations and two informal consultations 
occurred annually for the Pecos bluntnose shiner. The economic analysis 
assumes that twice as many consultations would occur if this area were 
designated as critical habitat for the silvery minnow, since the area 
would be doubled in size. However, the economic analysis also 
recognizes that this is likely an overstatement of the actual increase 
in consultations because consultations frequently occur on projects 
located outside of Pecos bluntnose shiner critical habitat, because of 
the interdependent nature of the river system and the presence of the 
species. Consequently, we do not believe that designating critical 
habitat within this river reach would provide additional benefits for 
the silvery minnow, because currently the activities that occur outside 
of critical habitat designated for the Pecos bluntnose shiner are also 
the subject of consultation. In the absence of the silvery minnow, we 
find little benefit to including this river reach in the critical 
habitat for the silvery minnow because of the presence of the Pecos 
bluntnose shiner and its designated critical habitat. Current and 
ongoing conservation activities for the Pecos bluntnose shiner are 
compatible with those of the silvery minnow such that reestablishment 
of the silvery minnow in this stretch of river should not be precluded 
in the future. Thus, we determine that any additional benefit from a 
designation of critical habitat in this river reach does not outweigh 
the benefit of excluding this area, as discussed below in the 
``Benefits of Exclusion'' section.
    The benefits of inclusion of the river reach in the lower Rio 
Grande in Big Bend National Park downstream of the park boundary to the 
Terrell/Val Verde County line, TX, would also result from the 
requirement under section 7 of the Act that Federal agencies consult 
with us to ensure that any proposed actions do not destroy or adversely 
modify critical habitat. However, as indicated in the economic 
analysis, we anticipate very little consultation activity within this 
area. The economic analysis (section 6.3.3) estimates that over the 
next 20 years there would be a total of 12 formal consultations and 6 
informal consultations if silvery minnow critical habitat were 
designated. The only Federal action that we are aware of within the 
river reach of the lower Rio Grande downstream of Big Bend National 
Park is the Big Bend National Park oversight and permitting authority 
for float trips, scientific research permits, environmental education, 
and law enforcement (R. Skiles, Big Bend National Park, pers. comm. 
2001). Therefore, unless there are other types of Federal permitting or 
authorization within this area, private and State-owned lands would not 
be affected. Additional activities that were used to estimate the 
numbers of consultations

[[Page 8108]]

for this area include: National Park management activities (e.g., 
pesticide application and fishing regulations), U.S. International 
Boundary and Water Commission channel maintenance activities, certain 
Service activities (e.g., fire management plans, fish stocking), and 
the U.S. Environmental Agency (EPA) NPDES permitting for the Presidio 
or Lajitas wastewater treatment facility. We find sufficient regulatory 
and protective conservation measures in place from the consultations 
regarding the activities described above. We believe there would be 
little benefit to a designation in this reach because this area is 
protected and managed by the National Park Service and the number of 
consultations expected to occur in this area is relatively low.
    As above, we believe that heightened public awareness of a listed 
species and its habitat may facilitate conservation efforts. 
Nevertheless, we believe that there would be little additional 
informational benefit gained from including the lower Rio Grande within 
designated critical habitat for the silvery minnow because we have 
identified in this final designation those areas that we believe are 
essential to the conservation of the species. For these reasons, we 
determine that any additional benefit of designation of critical 
habitat in this river reach does not outweigh the benefit of excluding 
this area, as discussed below.

(2) Benefits of Exclusion

    As discussed in the ``Recovery Plan'' section of this rule, the 
primary goals of the silvery minnow Recovery Plan are to: (1) Stabilize 
and enhance populations of the silvery minnow and its habitat in the 
middle Rio Grande valley; and (2) reestablish the silvery minnow in at 
least three other areas of its historic range (Service 1999). We 
believe that the best way to achieve the second recovery goal will be 
to use the authorities under section 10(j) of the Act. Consequently, 
this final rule outlines our conservation strategy that we believe is 
consistent with the species' Recovery Plan. The conservation strategy 
is to reestablish the silvery minnow, under section 10(j) of the Act, 
within areas of its historic range, possibly including the river reach 
in the middle Pecos River and the river reach in the lower Rio Grande. 
Since the silvery minnow is extirpated from these areas and natural 
repopulation is not possible without human assistance, we believe a 
10(j) rule is the appropriate tool to achieve this recovery objective. 
Nevertheless, any future recovery efforts, including reintroduction of 
the species to areas of its historic range, must be conducted in 
accordance with NEPA and the Act. An overview of the process to 
establish an experimental population under section 10(j) of the Act is 
described below.
    Section 10(j) of the Act enables us to designate certain 
populations of federally listed species that are released into the wild 
as ``experimental.'' The circumstances under which this designation can 
be applied are the following: (1) The population is geographically 
separate from non-experimental populations of the same species (e.g., 
the population is reintroduced outside the species' current range but 
within its probable historic range); and (2) we determine that the 
release will further the conservation of the species. Section 10(j) is 
designed to increase our flexibility in managing an experimental 
population by allowing us to treat the population as threatened, 
regardless of the species' status elsewhere in its range. Threatened 
status gives us more discretion in developing and implementing 
management programs and special regulations for a population and allows 
us to develop any regulations we consider necessary to provide for the 
conservation of a threatened species. In situations where we have 
experimental populations, certain section 9 prohibitions (e.g., harm, 
harass, capture) that apply to endangered and threatened species may no 
longer apply, and a special rule can be developed that contains the 
prohibitions and exceptions necessary and appropriate to conserve that 
species. This flexibility allows us to manage the experimental 
population in a manner that will ensure that current and future land, 
water, or air uses and activities will not be unnecessarily restricted 
and the population can be managed for recovery purposes.
    When we designate a population as experimental, section 10(j) of 
the Act requires that we determine whether that population is either 
essential or nonessential to the continued existence of the species, on 
the basis of the best available information. Nonessential experimental 
populations located outside National Wildlife Refuge System or National 
Park System lands are treated, for the purposes of section 7 of the 
Act, as if they are proposed for listing. Thus, for nonessential 
experimental populations, only two provisions of section 7 would apply 
outside National Wildlife Refuge System and National Park System lands: 
Section 7(a)(1), which requires all Federal agencies to use their 
authorities to conserve listed species, and section 7(a)(4), which 
requires Federal agencies to informally confer with us on actions that 
are likely to jeopardize the continued existence of a proposed species. 
Section 7(a)(2) of the Act, which requires Federal agencies to ensure 
that their activities are not likely to jeopardize the continued 
existence of a listed species, would not apply except on National 
Wildlife Refuge System and National Park System lands. Experimental 
populations determined to be ``essential'' to the survival of the 
species would remain subject to the consultation provisions of section 
7(a)(2) of the Act.
    In order to establish an experimental population, we must issue a 
proposed regulation and consider public comments on the proposed rule 
prior to publishing a final regulation. In addition, we must comply 
with NEPA. Also, our regulations require that, to the extent 
practicable, a regulation issued under section 10(j) of the Act 
represent an agreement between us, the affected State and Federal 
agencies, and persons holding any interest in land that may be affected 
by the establishment of the experimental population (see 50 CFR 
17.81(d)).
    The flexibility gained by establishment of an experimental 
population through section 10(j) would be of little value if a 
designation of critical habitat overlaps it. This is because Federal 
agencies would still be required to consult with us on any actions that 
may adversely modify critical habitat. In effect, the flexibility 
gained from section 10(j) would be rendered useless by the designation 
of critical habitat. In fact, section 10(j)(2)(C)(ii) of the Act states 
that critical habitat shall not be designated under the Act for any 
experimental population determined to be not essential to the continued 
existence of a species.
    The second goal of the Recovery Plan is to reestablish the silvery 
minnow in areas of its historic range. We strongly believe that, in 
order to achieve recovery for the silvery minnow, we would need the 
flexibility provided for in section 10(j) of the Act to help ensure the 
success of reestablishing the minnow in the middle Pecos River and 
lower Rio Grande areas. Use of section 10(j) is meant to encourage 
local cooperation through management flexibility. Critical habitat is 
often viewed negatively by the public since it is not well understood 
and there are many misconceptions about how it affects private 
landowners (Patlis 2001). We believe it is important for recovery of 
this species that we have the support of the public when we move toward 
meeting the second recovery goal. It is

[[Page 8109]]

critical to the recovery of the silvery minnow that we reestablish the 
species in areas outside of its current occupied range. The current 
population of silvery minnow in the middle Rio Grande is in an 
imperiled state, making reestablishment into other portions of its 
historic range extremely important.
    As noted above, nonessential experimental populations located 
within the National Park System are treated, for purposes of section 7 
of the Act, as if they are listed as threatened (50 CFR 17.83(b)). 
Thus, a nonessential experimental population established in the river 
reach in the lower Rio Grande downstream of the Big Bend National Park 
boundary (i.e., within the reach designated as a wild and scenic river) 
to the Terrell/Val Verde County line, TX, would be treated, for 
purposes of section 7, as a threatened species because this area is a 
component of the national wild and scenic rivers system that is 
administered by the Secretary of the Interior through the National Park 
Service and is considered part of the National Park System (16 U.S.C. 
1281(c)). These lands downstream of Big Bend National Park are owned by 
the State of Texas (Black Gap Wildlife Management Area) and 
approximately 12 to 15 private landowners. The National Park Service's 
management authority in the wild and scenic river designation currently 
extends 0.25 mi from the ordinary high water mark.
    For the past two years, Big Bend National Park has been working on 
a management plan for the ``outstanding remarkable values of the Rio 
Grande wild and scenic river'' (F. Deckert, Big Bend National Park, 
pers. comm. 2002). The development of the river management plan has 
involved stakeholders, including private landowners and the State of 
Texas. Throughout the stakeholder-based planning process, the Park has 
built trust among diverse and competing interests by encouraging open 
dialogue regarding various river management issues. If critical habitat 
were designated in this river reach, the introduction of additional 
Federal influence could jeopardize the trust and spirit of cooperation 
that has been established over the last several years (F. Deckert, 
pers. comm. 2002). The designation of critical habitat would be 
expected to adversely impact our, and possibly the Park's, working 
relationship with the State of Texas and private landowners, and we 
believe that Federal regulation through critical habitat designation 
would be viewed as an unwarranted and unwanted intrusion.
    The National Park Service expects to complete and finalize its 
management plan and EIS in 2003. We will review the river management 
plan when the draft EIS is released to suggest management 
recommendations for this river reach that are consistent with the 
recovery needs of the silvery minnow. We believe this area has the 
greatest potential for repatriating the species within an area of its 
historic range and believe this river reach also has the greatest 
potential for developing an experimental population under section 10(j) 
of the Act. In order for an experimental population to be successful, 
the support of local stakeholders--including the National Park Service, 
the State of Texas, private landowners, and other potentially affected 
entities--is crucial. In light of this and the fact that the river 
management plan will soon be completed, we find that significant 
benefits result from excluding this river reach from designation of 
critical habitat.
    On the middle Pecos River, we acknowledge that the NMISC has been 
actively acquiring and leasing water rights to meet the State's 
delivery obligations to TX as specified in the Pecos River Compact and 
pursuant to an Amended Decree entered by the U.S. Supreme Court. For 
example, between 1991 and 1999, $27.8 million was spent on the Pecos 
River water rights acquisition program. NM faced a shortfall in its 
Pecos River Compact delivery obligations for the year 2001 and the 
possibility of priority administration, in which the State Engineer 
would order junior water rights holders not to use water. Given this 
tight water situation and the Pecos River Compact delivery obligations, 
we believe that the flexibility of section 10(j) would be especially 
appropriate in the middle Pecos. Economic costs associated with 
endangered species management and critical habitat designation for the 
silvery minnow are discussed in the economic analysis. There are a 
variety of current and potential future costs associated with the 
ongoing water management and water reallocation on the middle Pecos 
River. The economic analysis and EIS discuss and analyze these costs in 
greater detail. We used the economic analysis and EIS to make our 
determinations on the benefits of including or excluding areas from the 
designation of critical habitat. Prior to making our final 
determination, we considered comments on the economic and other 
relevant impacts of all of the areas we determined to be essential for 
the conservation of the silvery minnow.
    In summary, we believe that the benefits of excluding the middle 
Pecos River and lower Rio Grande outweigh the benefits of their 
inclusion as critical habitat. Including these areas may result in some 
benefit through additional consultations with Federal agencies whose 
activities may affect critical habitat. However, overall this benefit 
is minimal because of the presence of the Pecos bluntnose shiner and 
its critical habitat in the middle Pecos River and the minimal number 
of estimated future consultations that are expected to occur within Big 
Bend National Park and the wild and scenic river designation that 
extends beyond the Park's boundaries. On the other hand, an exclusion 
will greatly benefit the overall recovery of the minnow by allowing us 
to move forward using the flexibility and greater public acceptance of 
section 10(j) of the Act to reestablish minnows in other portions of 
its historic range where it no longer occurs. This is likely the most 
important step in reaching recovery of this species and we believe that 
section 10(j), as opposed to a critical habitat designation, is the 
best tool to achieve this objective. Thus, we believe that an exclusion 
of these two areas outweighs any benefits that could be realized 
through a designation of critical habitat and we have not included 
these two areas within this critical habitat designation.
    The Pecos River and lower Rio Grande reaches were historically 
occupied but are currently unoccupied by the silvery minnow (Hubbs 
1940; Trevino-Robinson 1959; Hubbs et al. 1977; Bestgen and Platania 
1991). The silvery minnow occupies less than 5 percent of its historic 
range, and the likelihood of extinction from catastrophic events is 
high because of its limited range (Hoagstrom and Brooks 2000; Service 
1999). However, if critical habitat were designated in the middle Pecos 
River or lower Rio Grande, the likelihood of extinction of the species 
from the occupied reach of the middle Rio Grande would not decrease 
because critical habitat designation is not a process to reestablish 
additional populations within areas outside of the current known 
distribution. We believe that the exclusion of the river reaches of the 
middle Pecos River and the lower Rio Grande will not lead to the 
extinction of the species.

Relationship of Critical Habitat to Pueblo Lands Under Section 3(5)(A) 
and Exclusions Under Section 4(b)(2)

    In the proposed rule for the designation of critical habitat for 
the silvery minnow (June 6, 2002; 67 FR 39213), we indicated that if 
any management plans are submitted during the open comment period, we 
would

[[Page 8110]]

consider whether such plans provide adequate special management or 
protection for the species. We also indicated that we would use this 
information in determining which, if any, river reaches or portions of 
river reaches within the middle Rio Grande should not be included in 
the final designation of critical habitat for the silvery minnow. We 
based this discussion on section 3(5) of the Act, which defines 
critical habitat, in part, as areas within the geographical area 
occupied by the species ``on which are found those physical and 
biological features (I) essential to the conservation of the species 
and (II) which may require special management considerations and 
protection.'' We noted that ``special management considerations or 
protection'' is a term that originates in the definition of critical 
habitat and that adequate special management consideration or 
protection can be provided by a legally operative plan or agreement 
that addresses the maintenance and improvement of the primary 
constituent elements important to the species and manages for the long-
term conservation of the species. The three criteria identified in the 
proposed rule for determining if a plan provides adequate special 
management or protection are as follows: (1) A current plan or 
agreement must be complete and provide sufficient conservation benefit 
to the species; (2) the plan or agreement must provide assurances that 
the conservation management strategies will be implemented; and (3) the 
plan or agreement must provide assurances that the conservation 
management strategies will be effective (i.e., provide for periodic 
monitoring and revisions as necessary).
    In a recent opinion (Center for Biological Diversity v. Norton, 
Civ. No. 01-409 TUC DCB D. Ariz. Jan. 13, 2003), a federal district 
court determined that our definition of critical habitat, as it applies 
to special management, is not correct. The court stated that ``whether 
habitat does or does not require special management is not 
determinative on whether the habitat is ``critical'' to a threatened or 
endangered species.'' Although we do not necessarily agree with the 
court's analysis, we nevertheless do not intend to delete areas from 
this final designation because additional special management is not 
required. We do however, as explained below, believe that the 
management plans submitted by the Pueblos of Santo Domingo, Santa Ana, 
Sandia, and Isleta during the comment period provide for special 
management of the silvery minnow on their lands and we have, as 
explained below, excluded their lands under section 4(b)(2) of the Act.
    During the open comment period, we worked with the Pueblos of Santo 
Domingo, Santa Ana, Sandia, and Isleta to develop voluntary measures to 
conserve the silvery minnow on their lands. These Pueblos each 
completed special management plans for the silvery minnow and submitted 
them to us during the open comment period. Excluding the Tribal lands 
in this designation of critical habitat for the silvery minnow will not 
adversely affect the conservation and future delisting of the species. 
Whether or not a species has designated critical habitat, that species 
is protected from any actions resulting in an unlawful take, under 
section 9 of the Act, and from Federal actions that could jeopardize 
the species' continued existence. The four Pueblo plans are summarized 
below:
    (1) Santo Domingo Tribe Rio Grande Silvery Minnow Management Plan 
(Santo Domingo management plan): A resolution was passed by the Santo 
Domingo Tribal Council for the Santo Domingo management plan to 
exercise the Tribe's sovereign status and provide for special 
management protections and conservation of the silvery minnow. The 
Santo Domingo management plan sets the goal of gathering and analyzing 
data to formulate and prioritize actions to improve the status of these 
lands. Additionally, the Santo Domingo Tribe will attempt to secure 
funding to: (1) Determine and quantify the extent of the silvery minnow 
population and habitat found on Santo Domingo lands; (2) develop 
management actions and strategies to address the threats to the species 
and provide protection of silvery minnow populations and habitat; (3) 
develop methods and protocols for gathering, storing, and monitoring 
data for the Rio Grande watershed; and (4) analyze, revise, and 
strengthen the Santo Domingo management plan to promote long-term 
improvement of the watershed and protect the silvery minnow and other 
species.
    The Santo Domingo Tribe intends to coordinate with us to follow 
methods and protocols that were provided to the Tribe in 2001 to survey 
for silvery minnows or habitat, to conduct water quality sampling, to 
develop water quality standards, and to devise relocation or 
augmentation protocols (Santo Domingo 2002; Service 2001e). The Santo 
Domingo management plan organizes these activities into silvery minnow 
population and habitat monitoring, silvery minnow research, bosque (the 
riparian areas adjacent to the Rio Grande) restoration, and data 
sharing. Because Santo Domingo commits to implementing these 
activities, we find that the Santo Domingo management plan provides 
significant conservation benefit to the silvery minnow. We believe that 
the resolution passed by the Santo Domingo Tribal Council and the 
development of the Santo Domingo management plan demonstrate that the 
management plan will be implemented. The Santo Domingo management plan 
specifically provides periodic updates as appropriate, including 
updates based upon silvery minnow population and habitat monitoring and 
research.
    (2) Santa Ana Management Plan: During the open comment period, the 
Pueblo of Santa Ana submitted comments and a draft safe harbor 
agreement to us. The comments and draft safe harbor agreement indicate 
that the Pueblo is currently enhancing, restoring, and maintaining 
habitat for the silvery minnow and other species. The Pueblo's current 
natural resource programs--along with the draft safe harbor agreement--
will, along with providing other conservation benefits, serve as the 
foundation for managing the silvery minnow and other species within the 
Pueblo's lands. The Pueblo has actively coordinated with us to 
implement these voluntary conservation programs to augment the silvery 
minnow population within its lands and intends to continue its existing 
natural resource management programs that currently provide special 
management considerations or protections for the silvery minnow. These 
programs include ecosystem restoration, range and wildlife, water 
resources, GIS, and environmental education. The ecosystem restoration 
program concentrates on the restoration of riparian, wetland, and 
riverine systems by eradicating non-native plant species and restoring 
native wildlife habitat, including habitat for the silvery minnow. Its 
current scope includes developing methods and implementing bosque, 
wetland, and channel restoration along the Rio Grande within the 
boundaries of the Pueblo and in the Rio Jemez watershed. The range and 
wildlife program concentrates on improving the health of the Pueblo's 
rangeland. The water resources program is responsible for surface water 
and groundwater projects and programs ongoing and in development at the 
Pueblo. Activities currently being implemented and anticipated to 
continue focus on water quality standards development, technical 
support for water rights establishment, conserving riparian areas, 
improving

[[Page 8111]]

water quality, and reestablishing natural hydrologic processes. These 
natural resource management programs will collect monitoring data such 
as water quality information, stream geomorphologic assessments, 
aquatic studies, and vegetation surveys. We expect that periodic 
updates of information as well as water management improvements will 
occur because their natural resource programs incorporate monitoring 
and adaptive management principles.
    We believe that Santa Ana Pueblo currently provides, and will 
continue to provide, special management for the conservation of the 
silvery minnow through its existing natural resource management 
programs. Because Santa Ana commits to implementing the activities 
described above, we conclude that the management of Santa Ana Pueblo 
lands and those described under the draft safe harbor agreement provide 
significant conservation benefit to the silvery minnow. We believe that 
the existing natural resource program and draft safe harbor agreement 
demonstrate that these voluntary management activities will be 
implemented. In fact, we have previously commented that Santa Ana's 
active restoration program includes many standard recommendations we 
make concerning fish and wildlife and their habitat, such as expansion 
of shallow, low-velocity habitat in the Rio Grande, creation and 
restoration of riparian and wetland areas, protection and enhancement 
of aquatic habitat, and establishment of native plant species in 
riparian areas cleared of non-native vegetation (Service 2001f). The 
Santa Ana natural resource program and draft safe harbor agreement also 
provide for periodic updates as appropriate.
    (3) Pueblo of Sandia Bosque Management Plan (Sandia management 
plan): A resolution passed by the Pueblo of Sandia Tribal Council 
adopts the management plan. The resolution, among other things, 
identifies that the Sandia management plan formalizes bosque 
restoration activities, thus demonstrating the Pueblo's commitment to 
protect the bosque, including the silvery minnow. The Sandia management 
plan provides a conservation benefit to the silvery minnow by enhancing 
and restoring the species' habitat through bosque restoration efforts, 
water quality monitoring, fire prevention activities, wetland 
enhancements, and natural pond restoration. The goals of the Sandia 
management plan are to: (1) Create and sustain diverse habitats within 
the bosque; (2) reduce and eradicate invasive species; (3) plant native 
grasses, trees, and shrubs; (4) increase water retention and yield of 
the riparian area; (5) encourage the reintroduction of native species, 
including the silvery minnow and the Southwestern willow flycatcher; 
and (6) continue water quality monitoring to determine if degradation 
has contributed to the decline of the silvery minnow. The Pueblo also 
developed specific objectives to provide for special management 
considerations or protections of the silvery minnow, including: 
determining silvery minnow distribution, abundance, mesohabitat and 
habitat preference, and evaluating water quality impacts. Additionally, 
the Pueblo will prepare a feasibility study for creating silvery minnow 
habitat and will continue cooperative research efforts with us.
    As an example of current protection, Sandia Pueblo has surface 
water quality standards pursuant to the Clean Water Act. To support 
these standards, the Pueblo has an intensive monitoring program to 
assess water quality compliance in relation to its established 
standards. In addition, the Pueblo is currently engaged with us in 
conducting a water quality study. The study is designed to assess water 
quality in relation to the silvery minnow and its habitat. The results 
of this study will be used to develop and promote long-term strategies 
that will protect and conserve the silvery minnow.
    We find that the Sandia management plan is complete and provides 
significant conservation benefit to the silvery minnow as described 
above. We believe that the resolution passed by the Pueblo of Sandia 
Tribal Council concerning the Sandia management plan demonstrates that 
the management plan will be implemented. The Sandia management plan 
also will be periodically updated, as appropriate, on the basis of 
results of ongoing Federal and State agency programs and studies.
    (4) The Pueblo of Isleta Riverine Management Plan: Rio Grande 
Silvery Minnow (Isleta management plan). A resolution passed by the 
Tribal Council of the Pueblo of Isleta adopts the Isleta management 
plan. The resolution, among other things, demonstrates the Pueblo's 
commitment through the Isleta management plan to protect, conserve, and 
promote the management of the silvery minnow and its associated habitat 
within the boundaries of Isleta Pueblo. Management activities covered 
by the Isleta Management Plan include silvery minnow population 
monitoring, habitat protection, and habitat restoration.
    As an example of current protection, Isleta Pueblo has surface 
water quality standards pursuant to the Clean Water Act. The EPA has 
taken the surface water quality standards developed by Isleta Pueblo 
into consideration in the development of point source discharge 
permits; these standards minimize potential water quality impacts on 
water uses and resources, including the protection of the silvery 
minnow. The Pueblo regularly monitors compliance with these surface 
standards, and is currently engaged with us in conducting a water 
quality study. The study is designed to assess water quality in 
relation to the silvery minnow and its habitat. The results of this 
study will be used to develop and promote long-term strategies that 
will protect and conserve the silvery minnow.
    The Isleta management plan sets the overall management goals of (1) 
determining, quantifying, and assessing silvery minnow populations 
within Isleta Pueblo; (2) developing and refining management actions to 
address potential threats to the silvery minnow; (3) prescribing 
measures to sustain existing silvery minnow populations and habitat and 
enhance numbers; and (4) promoting a comprehensive integrated resource 
management approach for the riverine ecosystem. These goals, conducted 
in cooperation with the FWS, will be accomplished by silvery minnow 
population and habitat assessment and monitoring, including surveys, 
egg sampling and collection, and silvery minnow rescues.
    We find that the Isleta management plan is complete and the 
commitment to implement the activities described above provides 
significant conservation benefit to silvery minnow. We believe that the 
resolution passed by the Tribal Council of the Pueblo of Isleta 
concerning the final Isleta management plan demonstrates that the 
management plan will be implemented. The Isleta management plan 
specifically provides periodic updates as appropriate, including 
updates based upon silvery minnow population, habitat, and water 
quality monitoring and studies.
    Section 4(b)(2) allows the Service to exclude areas form critical 
habitat designation if the benefits of such exclusion outweigh the 
benefits of specifying such areas as critical habitat, unless exclusion 
would result in the extinction of the species. If excluding an area 
from a critical habitat designation will provide substantial 
conservation benefits, and at the same time including the area fails to 
confer a counter-balancing positive regulatory or educational benefit 
to the species, then the benefits of excluding the area from critical 
habitat outweigh the benefits of including it.

[[Page 8112]]

    The Service has analyzed the benefits of including the Pueblos of 
Santa Domingo, Santa Ana, Sandia, and Isleta as part of the critical 
habitat designation and the benefits of excluding these areas, and 
determined that the benefits of exclusion outweigh those of inclusion. 
A major factor in the analysis described below is that, even if 
excluded, these river reaches owned and managed by the Pueblos will 
nonetheless receive special management and protection through the 
Pueblos management plans, which were submitted during the open comment 
period for the proposed rule. Under these management plans, the silvery 
minnow will benefit from monitoring, restoration, enhancement, and 
survey efforts. The Service has also determined that exclusion would 
not result in the extinction of the species.

(1) Benefits of Inclusion

    There are few additional benefits of including the Pueblos of Santa 
Domingo, Santa Ana, Sandia, and Isleta in this critical habitat 
designation beyond what will be achieved through the implementation of 
their management plans. The principal benefit of any designated 
critical habitat is that activities in and affecting such habitat 
require consultation under section 7 of the Act. Such consultation 
would ensure that adequate protection is provided to avoid destruction 
or adverse modification of critical habitat. If adequate protection can 
be provided in another manner, the benefits of including any area in 
critical habitat are minimal. The economic analysis found that the 
Bureau of Indian Affairs (BIA) has no consultation history for the 
silvery minnow (i.e., no consultations have been conducted since the 
species was listed). However, the economic analysis found that, 
consultations may occur in the future for water trades or voluntary 
leasing that would benefit the silvery minnow. The economic analysis 
estimated 6 informal consultations may occur over the next 20 years, 
resulting from these beneficial water trades, but that no formal 
consultations were likely. These consultations would occur regardless 
of whether critical habitat is designated, because the species occupies 
these four areas. Section 7 consultation under the jeopardy standards 
will still be required for activities affecting the silvery minnow. 
Beyond these informal consultations, we do not expect any additional 
consultations.
    Although we believe the likelihood of additional consultations is 
small, consultation requirements under section 7 of the Act would be 
triggered as a result of the funding or permitting processes 
administered by the Federal agency involved. The benefit of critical 
habitat designation would ensure that any actions funded by or permits 
given by a Federal agency would not likely destroy or adversely modify 
any critical habitat. Without critical habitat, projects would still 
trigger consultation requirements under the Act because the silvery 
minnow is currently present in the middle Rio Grande. Given that no 
consultations have occurred with the BIA or the Pueblos since the 
silvery minnow was listed as endangered in 1994 and the overall low 
likelihood of Federal projects being proposed in these areas, the 
Service believes there is almost no regulatory benefit of a critical 
habitat designation in this area. Consequently, the designation of 
critical habitat in these areas would provide minimal, if any, 
regulatory benefit to the species.
    Another possible benefit is that the designation of critical 
habitat can serve to educate the public regarding the potential 
conservation value of an area, and this may focus and contribute to 
conservation efforts by other parties by clearly delineating areas of 
high conservation value for certain species. Any information about the 
silvery minnow and its habitat that reaches a wide audience, including 
other parties engaged in conservation activities, would be considered 
valuable. However, the Pueblos are already working with the Service to 
address the habitat needs of the species. Further, these areas were 
included in the proposed designation, which itself has reached a wide 
audience, and has thus provided information to the broader public about 
the conservation value of these areas. Thus, the educational benefits 
that might follow critical habitat designation, such as providing 
information to the BIA , BOR, or Pueblos on areas that are important 
for the long-term survival and conservation of the species, have 
already been provided by proposing these areas as critical habitat. 
Alternatively, the same or greater educational benefits will be 
provided to these lands if they are excluded from the designation, 
because the management plans provide for conservation benefits above 
any that would be provided by designating critical habitat. For 
example, the educational aspects are likely greater for these areas if 
they are not included in the designation because the Pueblos will 
continue to work cooperatively toward the conservation of the silvery 
minnow, which will include continuing, initiating, and completing 
scientific studies (see discussion below). For these reasons, then, we 
believe that designation of critical habitat would have few, if any, 
additional benefits beyond those that will result from continued 
consultation under the jeopardy standard.

(2) Benefits of Exclusion

    The benefits of excluding the Pueblos of Santa Domingo, Santa Ana, 
Sandia, and Isleta from designated critical habitat are more 
significant. The proposed critical habitat designation included 29.5 mi 
(47.5 km) of river through these areas. We believe that not designating 
critical habitat on these areas would have substantial benefits 
including: (1) The furtherance of our Federal Trust obligations and our 
deference to the Pueblos of Santa Domingo, Santa Ana, Sandia, and 
Isleta to develop and implement Tribal conservation and natural 
resource management plans for their lands and resources within the Rio 
Grande ecosystem, which includes the silvery minnow and its habitat; 
(2) the establishment and maintenance of effective working 
relationships to promote the conservation of the silvery minnow and its 
habitat; (3) the allowance for continued meaningful collaboration and 
cooperation in scientific studies to learn more about the life history 
and habitat requirements of the species; and (4) providing conservation 
benefits to the Rio Grande ecosystem and the silvery minnow and its 
habitat that might not otherwise occur.
    As detailed above, we met with Pueblos and Tribes to discuss how 
each might be affected by the designation of critical habitat. During 
the open comment period, we established effective working relationships 
with the Pueblos of Santa Domingo, Santa Ana, Sandia, and Isleta. As 
part of our relationship, we provided technical assistance to each of 
these four Pueblos to develop voluntary measures to conserve the 
silvery minnow and its habitat on their lands. These voluntary measures 
are contained within special management plans that each of these 
Pueblos submitted during the open comment period (see discussion 
above). These actions were conducted in accordance with Secretarial 
Order 3206, ``American Indian Tribal Rights, Federal-Tribal Trust 
Responsibilities, and the Endangered Species Act'' (June 5, 1997); 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 relevant provision of the Departmental

[[Page 8113]]

Manual of the Department of the Interior (512 DM 2). We believe that 
these Pueblos should be the governmental entities to manage and promote 
the conservation of the silvery minnow on their lands. During our 
meetings with each of these Pueblos, we recognized and endorsed their 
fundamental right to provide for resource management activities, 
including those relating to the Rio Grande ecosystem. Much of our 
discussions centered on providing technical assistance to the Pueblos 
to develop, continue, or expand natural resource programs such that the 
designation of critical habitat for the silvery minnow would likely be 
unnecessary.
    We find that other conservation benefits could be provided to the 
Rio Grande ecosystem and the silvery minnow and its habitat by 
excluding the Pueblos of Santa Domingo, Santa Ana, Sandia, and Isleta 
from the designation. For example, as part of maintaining an effective 
working relationship with each Pueblo, conservation benefits, including 
silvery minnow augmentation, population and habitat monitoring, silvery 
minnow research, habitat restoration, and the development of water 
leases may be possible. In fact, during our discussions with each of 
the Pueblos, we were informed that critical habitat would be viewed as 
an intrusion on their sovereign abilities to manage natural resources 
in accordance with their own policies, customs, and laws. To this end, 
we found that each Pueblo would prefer to work with us on a Government-
to-Government basis. For these reasons, we believe that our working 
relationships with the Pueblos of Santa Domingo, Santa Ana, Sandia, and 
Isleta would be maintained if they are excluded from the designation of 
critical for the silvery minnow. We view this as a substantial benefit.
    Proactive voluntary conservation efforts are necessary to promote 
the recovery of the silvery minnow (Service 1999). Consideration of 
this issue is especially important in areas where the status of the 
species is uncertain or unknown. Recovery of the silvery minnow will 
require access to all areas of the middle Rio Grande and permission for 
monitoring and other efforts (e.g., augmentation of the existing 
population, water leasing, etc). Because we have not had permission 
from the Pueblos within the Cochiti reach, surveys to determine the 
status of the silvery minnow have not been conducted since the mid-
1990s (Platania 1995; Hoagstrom and Brooks 2000). Pueblo cooperation is 
essential to obtain permission for these monitoring activities. As 
described above, the Santo Domingo intends to coordinate with us to 
survey for silvery minnows or habitat, to conduct water quality 
sampling, to develop water quality standards, and to devise relocation 
or augmentation protocols. Santa Ana Pueblo will continue to actively 
coordinate with us to implement a variety of voluntary conservation 
programs to augment the silvery minnow population within its lands and 
intends to continue its existing natural resource management programs 
that currently provide special management considerations or protections 
for the silvery minnow. Sandia Pueblo intends to enhance and restore 
the species' habitat through bosque restoration efforts, water quality 
monitoring, fire prevention activities, wetland enhancements, and 
natural pond restoration. Finally, Isleta Pueblo intends to protect, 
conserve, and promote the management of the silvery minnow and its 
associated habitat including population monitoring, habitat protection, 
habitat restoration, and continued water quality standards. 
Consequently, we view each of the special management plans as a 
starting point for cooperative and productive relationships that have 
the potential to provide additional substantive conservation benefits 
to the silvery minnow and its habitat. The additional benefits would be 
less likely if critical habitat was designated because the Pueblos view 
critical habitat as an intrusion on their ability to manage their own 
lands and trust resources.
    The special management plans and comments submitted by each of the 
Pueblos documents that meaningful collaborative and cooperative 
scientific studies will begin or continue within their lands. These 
commitments demonstrate the willingness of each of the Pueblos to work 
cooperatively with us toward landscape-scale conservation efforts that 
will benefit the silvery minnow. Each of the Pueblos has committed to 
several ongoing or future management, restoration, enhancement, and 
survey activities that would not occur as a result of critical habitat 
designation. The Pueblos of Sandia and Isleta are currently 
participating in a water quality study with us. Santo Domingo Pueblo 
indicated that, among other activities, it will attempt to secure 
funding to implement silvery minnow and habitat inventories, water 
quality sampling, and the development of water quality standards. Santa 
Ana indicated that water quality data, stream geomorphology 
assessments, and aquatic and vegetation studies will continue. 
Therefore, we believe that the results of these or other similar 
studies will be used to develop and promote long-term strategies that 
will protect and conserve the silvery minnow and its habitat within the 
Pueblo lands of Santa Domingo, Santa Ana, Sandia, and Isleta. The 
benefits of excluding these areas from critical habitat will encourage 
the continued cooperation and development of data-sharing protocols and 
scientific studies as part of implementing the special management 
plans. If these areas were designated as critical habitat, we believe 
it is unlikely that much of this information would be available to us.
    In addition to management actions described above to address the 
conservation needs of the silvery minnow, we discussed with each of the 
Pueblos possible future amendments to the special management plans to 
include voluntary conservation efforts for other listed species and 
their habitat (e.g., southwestern willow flycatcher). All of the 
Pueblos indicated their willingness to work cooperatively with us to 
benefit other listed species. However, these future voluntarily 
management actions will likely be contingent upon whether lands on 
these four Pueblos are designated as critical habitat for the silvery 
minnow. Thus, a benefit of excluding these lands would be future 
voluntary conservation efforts that would benefit other listed species.
    In summary, the benefits of including the Pueblos of Santa Domingo, 
Santa Ana, Sandia, and Isleta in critical habitat are small, and are 
limited to minor educational benefits. The benefits of excluding these 
areas from being designated as critical habitat for silvery minnow are 
more significant, and include encouraging the continued development and 
implementation of the special management measures such as monitoring, 
survey, enhancement, and restoration activities that are planned for 
the future or are currently being implemented. These programs will 
allow the Pueblos to manage their natural resources to benefit the Rio 
Grande ecosystem and silvery minnow, without the perception of Federal 
Government intrusion. This philosophy is also consistent with our 
published policies on Native American natural resource management. The 
exclusion of these areas will likely also provide additional benefits 
to the species that would not otherwise be available to encourage and 
maintain cooperative working relationships. We find that the benefits 
of excluding these areas from critical habitat designation outweigh the 
benefits of including these areas.
    As noted above, the Service may exclude areas from the critical 
habitat designation only if it is determined, ``based on the best 
scientific and

[[Page 8114]]

commercial data available, that the failure to designate such area as 
critical habitat will result in the extinction of the species 
concerned.'' Here, we have determined that exclusion of the Pueblo 
lands of Santo Domingo, Santa Ana, Sandia, and Isleta from the critical 
habitat designation will not result in the extinction of the silvery 
minnow. First, activities on these areas that may affect the silvery 
minnow will still require consultation under section 7 of the Act. 
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 listed species. Therefore, even 
without critical habitat designation on these lands, activities that 
occur on these lands cannot jeopardize the continued existence of the 
silvery minnow. Second, each of the Pueblos have committed to 
protecting and managing according to their special management plans and 
natural resource management objectives. In short, the Pueblos have 
committed to greater conservation measures on these areas than would be 
available through the designation of critical habitat. With these 
natural resource measures, we have concluded that this exclusion from 
critical habitat will not result in the extinction of the silvery 
minnow. Accordingly, we have determined that the Pueblo lands of Santa 
Domingo, Santa Ana, Sandia, and Isleta should be excluded under 
subsection 4(b)(2) of the Act because the benefits of exclusion 
outweigh the benefits of inclusion and will not cause the extinction of 
the species. For this reason, we are excluding from this critical 
habitat designation the Pueblo lands of Santa Domingo, Santa Ana, 
Sandia, and Isleta.

Critical Habitat

    Critical habitat is defined in section 3(5)(A) of the Act as--(i) 
the specific areas within the geographic 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 
geographic 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 by the Act, means the use of all 
methods and procedures that are necessary to bring an endangered or a 
threatened species to the point at which listing under the Act is no 
longer necessary.
    Section 4(b)(2) of the Act requires that we base critical habitat 
designation on the best scientific and commercial data available, 
taking into consideration the economic impact, and any other relevant 
impact, of specifying any particular area as critical habitat. We may 
exclude areas from critical habitat designation if we determine that 
the benefits of exclusion outweigh the benefits of including the areas 
as critical habitat, provided the exclusion will not result in the 
extinction of the species.
    Designation of critical habitat helps focus conservation activities 
by identifying areas that are essential to the conservation of the 
species and alerting the public and land management agencies to the 
importance of an area to conservation. Within areas currently occupied 
by the species, critical habitat also identifies areas that may require 
special management or protection. Critical habitat receives protection 
from destruction or adverse modification through required consultation 
under section 7 of the Act with regard to actions carried out, funded, 
or authorized by a Federal agency. Where no such Federal agency action 
is involved, critical habitat designation has no bearing on private 
landowners, State, or Tribal activities. Aside from the added 
protection provided under section 7, critical habitat does not provide 
other forms of protection to designated lands.
    Designating critical habitat does not, in itself, lead to recovery 
of a listed species. Designation does not create a management plan, 
establish numerical population goals, prescribe specific management 
actions (inside or outside of critical habitat), or directly affect 
areas not designated as critical habitat. Specific management 
recommendations for areas designated as critical habitat are most 
appropriately addressed in recovery, conservation, and management 
plans, and through section 7 consultations and section 10 permits. 
Critical habitat designations do not signal that habitat outside the 
designation is unimportant or may not be required for recovery.
    Areas outside the critical habitat designation will continue to be 
subject to conservation actions that may be implemented under section 
7(a)(1), the regulatory protections afforded by the section 7(a)(2) 
jeopardy standard, and the section 9 take prohibition. Federally funded 
or assisted 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 under section 10 of the Act, or conservation 
planning efforts for other species if new information available to 
these planning efforts calls for a different outcome.

Methods

    In determining areas that are essential to conserve the silvery 
minnow, we used the best scientific and commercial data available. This 
included data from research and survey observations published in peer-
reviewed articles, recovery criteria outlined in the Recovery Plan 
(Service 1999), data collected from reports submitted by biologists 
holding section 10(a)(1)(A) recovery permits, and comments received on 
the previous proposed and final rule, draft economic analysis, and 
environmental assessment. We have emphasized areas known to be occupied 
by the silvery minnow and described other river reaches that were 
identified in the Recovery Plan which we believe are important for 
possible reintroduction and recovery (Service 1999).

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 are required to base critical habitat designations on the 
best scientific and commercial data available and to consider those 
physical and biological features (primary constituent elements) that 
are essential to the conservation of the species and, within areas 
currently occupied by the species, may require special management 
considerations or protection. Those physical and biological features 
may include, but are not limited to, space for individual and 
population growth, and for normal behavior; food, water, or other 
nutritional or physiological requirements; cover or shelter; sites for 
breeding, reproduction, or rearing of offspring; and habitats that are 
protected from disturbance or are representative of the historic 
geographical and ecological distributions of a species.
    The various life-history stages of the silvery minnow require 
diverse habitats. The following discussion summarizes the biological 
requirements of the silvery minnow relevant to identifying the primary 
constituent elements of its critical habitat.
    The silvery minnow historically inhabited portions of the wide, 
shallow rivers and larger streams of the Rio Grande basin, 
predominantly the Rio Grande and the Pecos River (Bestgen

[[Page 8115]]

and Platania 1991). Survey results indicated that adults were common in 
shallow and braided runs over sand substrate, and almost never occurred 
in habitats with bottoms of gravel or cobble, while young-of-year fish 
(less than 1 year old) occupied shallow, low-velocity backwaters with 
sand-silt substrates (Dudley and Platania 1997; Platania and Dudley 
1997; Platania 1991; Remshardt et al. 2001). Young-of-year silvery 
minnows were infrequently found at the same time in the same habitat as 
adults. River reaches dominated by straight, narrow, incised (deep) 
channels with rapid flows are not typically occupied by the silvery 
minnow (Bestgen and Platania 1991).
    The habitats most often occupied by silvery minnow were 
characterized by low (<20 cm) to moderate depths (31 to 40 cm), little 
(<10 cm/s) to moderate (11 to 30 cm/s) water velocity, and silt and 
sand substrata (Dudley and Platania 1997; Remshardt et al. 2001). It is 
believed that silvery minnow select debris piles, pools, and backwaters 
as habitat, and generally avoid main channel runs (Dudley and Platania 
1997).
    The silvery minnow is believed to be a generalized forager, feeding 
upon items suspended in the water column and items lying on the 
substrate (e.g., plankton, algae, diatoms) (Sublette et al. 1990; 
Dudley and Platania 1997; Service 1999). The silvery minnow's elongated 
and coiled gastrointestinal tract suggests that detritus (partially 
decomposed plant or animal matter), including sand and silt, is scraped 
from the river bottom (Sublette et al. 1990). Other species of 
Hybognathus have similar food habits, consuming rich organic ooze and 
detritus found in silt or mud substrates (Pflieger 1997).
    The silvery minnow is a pelagic spawner, with each female capable 
of producing an average of 3,000 semibuoyant, non-adhesive eggs during 
a spawning event (Platania 1995; Platania and Altenbach 1998). 
Collection of eggs in the middle of May, late May, early June, and late 
June suggest a contracted spawning period in response to a spring 
runoff or spike (increase in flow that occurs when winter snows melt) 
(Service 1999; BOR 2001a). However, the peak of egg production appears 
to occur in mid-May (Smith 1998, 1999). If the spring spike occurs at 
the wrong time or is reduced, then silvery minnow reproduction could be 
impacted. Similar to other species of Hybognathus in other drainages 
(Lehtinen and Layzer 1988; Taylor and Miller 1990), the silvery minnow 
appears capable of multiple spawns. For example, a late spawn was 
documented in the Isleta and San Acacia reaches on July 24, 25, and 26, 
2002, following a high flow event produced by a thunderstorm (see also 
Dudley and Platania 2002d). This spawn was smaller than the typical 
spawning event in May, but a significant number of eggs was collected 
(N = 496) in 2 hours of effort (J. Smith, NMESFO, pers. comm. 2002). In 
2002, small spawning events (a few eggs in each spawn) have been 
documented in all reaches except the Cochiti Reach as late as August 7 
(J. Smith, NMESFO, pers. comm. 2002).
    Platania (1995, 2000) found that early development and hatching of 
eggs is correlated with water temperature. Silvery minnow eggs raised 
in 30[deg]C water hatched in about 24 hours, while eggs reared in 
20[deg]C water hatched within 50 hours. Eggs were 1.6 mm (0.06 in) in 
size upon fertilization, but quickly swelled to 3 mm (0.12 in). 
Recently hatched larval fish are about 3.7 mm (0.15 in) in standard 
length and grow about 0.15 mm (0.005 in) per day during the larval 
stages. Eggs and larvae remain in the drift for 3 to 5 days, and may be 
transported from 134 to 223 mi (216 to 359 km) downstream depending on 
river flows and habitat conditions (e.g., debris piles, low velocity 
backwaters) (Platania and Altenbach 1998). About 3 days after hatching, 
the larvae begin moving to low-velocity habitats where food (mainly 
phytoplankton and zooplankton) is abundant and predators are scarce. 
Because eggs and larvae can be swept downstream, where recruitment 
(that portion of young-of-the-year fish added to the breeding 
population) of fish may be poor in the current degraded condition of 
the middle Rio Grande (e.g., channelization, banks stabilization, levee 
construction, disruption of natural processes throughout the 
floodplain, etc.), adequate stream length appears to be an important 
determinant of reproductive success.
    Platania (1995) indicated that the downstream transport of eggs and 
larvae of the silvery minnow over long distances may have been, 
historically, beneficial to the survival of their populations. This 
behavior could have promoted recolonization of reaches impacted during 
periods of natural drought (Platania 1995). Alternatively, in a natural 
functioning river system (e.g., a natural, unregulated flow regime), a 
variety of low-velocity refugia (e.g., oxbows, backwaters, etc.) would 
have been available for silvery minnow, and lengthy downstream drift of 
eggs and larvae may not have been common (J. Brooks, U.S. Fish and 
Wildlife Service pers. comm., 2001). Currently, the release of floating 
silvery minnow eggs may replenish downstream reaches, but the presence 
of the diversion dams (Angostura, Isleta, and San Acacia Diversion 
Dams) prevents recolonization of upstream habitats (Platania 1995). As 
upstream reaches are depleted upstream, and diversion structures 
prevent upstream movements, population decline of the species within 
river reaches may occur through loss of connectivity (i.e., preventing 
upstream movement of fish). Silvery minnows, eggs, and larvae are also 
transported downstream to Elephant Butte Reservoir, where it is 
believed that survival of these fish is highly unlikely because of poor 
habitat, and, more importantly, because of predation from reservoir 
fishes (Service 2001b). The population center (i.e., the river reach 
that contains the majority of adult silvery minnows) is believed to 
have moved farther downstream over the last several years (Dudley and 
Platania 2001; 2002a; 2002b). For example, in 1997, it was estimated 
that 70 percent of the silvery minnow population was found in the reach 
below San Acacia Diversion Dam (Dudley and Platania 1997). Moreover, 
during surveys in 1999, over 95 percent of the silvery minnows captured 
occurred downstream of San Acacia Diversion Dam (Dudley and Platania 
1999a; Smith and Jackson 2000). Probable reasons for this distribution 
include: (1) The spawning of semibuoyant eggs during the spring and 
early summer high flows, resulting in downstream transport of eggs and 
larval fish; (2) diversion dams that restrict or preclude the movement 
of fish into upstream reaches; and (3) reduction in the amount of 
available habitat due to the current degraded condition of some areas 
within the middle Rio Grande (e.g., channelization, streambed 
degradation, reduction in off-channel habitat, and the general 
narrowing and incising of the stream channel) (Platania 1998; Lagassee 
1981; BOR 2001).
    Most Great Plains streams are highly variable environments. Fish in 
these systems (e.g., the Rio Grande) are subjected to extremes in water 
temperatures, flow regimes, and overall water quality conditions 
(especially the concentration of dissolved oxygen). Native fish in 
these streams often exhibit life history strategies and microhabitat 
preferences that enable them to cope with these natural conditions. For 
example, Matthews and Maness (1979) reported that the synergistic 
(combined) effects of high temperature, low oxygen, and other

[[Page 8116]]

stressors probably limit fishes in streams of the Great Plains.
    The silvery minnow evolved in a highly variable ecosystem, and is 
likely more tolerant of elevated temperatures and low dissolved oxygen 
concentrations for short periods than other non-native species. 
Although little is known about the upper tolerance limits of the 
silvery minnow, when water quality conditions degrade, stress 
increases, and fish generally die (e.g., see Matthews and Maness 1979; 
Ostrand and Wilde 2001). Generally, it is believed that during periods 
of low flow or no flow, Great Plains fishes seek refugia in large 
isolated pools, backwater areas, or adjoining tributaries (Deacon and 
Minckley 1974; Matthews and Maness 1979). Fish in these refugia strive 
to survive until suitable flow conditions return and these areas 
reconnect with the main river channel. This pattern of retraction and 
recolonization of occupied areas in response to flow and other habitat 
conditions is typical of fishes that endure harsh conditions of Great 
Plains rivers and streams (Deacon and Minckley 1974; Matthews and 
Maness 1979).
    Localized reductions in abundance are not typically a concern where 
sufficient numbers of the species survive, because river reaches can be 
recolonized when conditions improve. However, habitat conditions such 
as oxbows, backwaters, or other refugia that were historically present 
on the Rio Grande and Pecos River and were a component of natural 
population fluctuations (e.g., extirpation and recolonization) have 
been dramatically altered or lost (Bestgen and Platania 1991; Hoagstrom 
2000; BOR 2001a, 2001b). Over the past several decades, the extent of 
areas in the Rio Grande and Pecos Rivers that have periodically lost 
flow has increased due to human alterations of the watersheds and 
stream channels and diversion of the streamflows (Service 1994).
    Variation in stream flow (i.e., flow regime) strongly affects some 
stream fish (Schlosser 1985). For example, juvenile recruitment of some 
stream fish is highly influenced by stable flow regimes (Schlosser 
1985; Hoagstrom 2000). When sufficient flows persist and other habitat 
needs are met, then recruitment into the population is high. Silvery 
minnows and other Great Plains or desert fishes cannot currently 
survive when conditions lead to prolonged recurring periods of low or 
no flow of long stretches of river (Hubbs 1974; Hoagstrom 2000). Fish 
mortality likely begins from degraded water quality (e.g., increasing 
temperatures, p.H., and decreasing dissolved oxygen) and loss of refuge 
habitat prior to prolonged periods of low or no flow (J. Brooks, pers. 
comm 2001; Ostrand and Wilde 2001). For instance, a reduction of stream 
flow reduces the amount of water available to protect against 
temperature oscillations, and high temperatures from reduced water flow 
frequently kill fish before prolonged periods of no flow occurs (Hubbs 
1990).
    It is also possible that fish may subsequently die from living 
under suboptimal conditions or that their spawning activities may be 
significantly disrupted (Hubbs 1974; Platania 1993b). Such conditions 
are in part responsible for the current precarious status of the 
silvery minnow. For example, management of water releases from 
reservoirs, evaporation, diversion dams, and irrigation water 
deliveries have resulted in dewatered habitat--causing direct mortality 
and isolated pools that cause silvery minnow mortality as a result of 
poor water quality and predation from other fish and predators. Despite 
efforts to manage water resources to benefit the silvery minnow, 
periods of intermittency have and continue to occur. Portions of the 
middle Rio Grande were dewatered in the period 1996 through 2001 
(Service 2001b; J. Smith, pers. comm. 2001). In 1996, about 34 mi (58 
km) out of the 56 mi (90 km) from the San Acacia Diversion Dam to 
Elephant Butte Reservoir were dewatered. In 1997, water flows ceased at 
the south boundary of the Bosque del Apache National Wildlife Refuge, 
resulting in the dewatering of 14 mi (22.5 km) of silvery minnow 
habitat. In 1998, the Rio Grande was discontinuous within the Bosque 
del Apache National Wildlife Refuge, dewatering about 20 mi (32 km) of 
habitat. In 1999, flows ceased about 1 mi upstream of the Bosque del 
Apache National Wildlife Refuge northern boundary, dewatering about 24 
mi (39 km) of habitat. A similar event occurred in 2000, but not to the 
extent of the 1999 drying. In 2001, approximately 9 combined mi (14 km) 
of river dried within the Bosque del Apache National Wildlife Refuge 
and south of San Marcial (Smith 2001). Drying occurred during the 2002 
irrigation season in the Isleta and San Acacia Reaches. Between June 
and August 2002, approximately 25 mi of river in the San Acacia Reach 
and 14 mi in the Isleta Reach dried. Because of prolonged recurring 
periods of low or no flow through multiple years, the status of the 
silvery minnow has declined to alarmingly low levels (Dudley and 
Platania 2001, 2002a, 2002b, 2002c, 2002d, 2002e).
    The primary constituent elements identified below provide a 
qualitative description of those physical and biological features 
necessary to ensure the conservation of the silvery minnow. We 
acknowledge that if thresholds were established as part of a critical 
habitat designation, they could be revised if new data became available 
(50 CFR 424.12(g)); however, the process of new rulemaking can take 
years (see 50 CFR 424.17), as opposed to reinitiating and completing a 
formal consultation, which takes months (see 50 CFR 402.14). Formal 
consultation provides an up-to-date biological status of the species or 
critical habitat (i.e., environmental baseline) which is used to 
evaluate a proposed action during formal consultations. Consequently, 
we believe it is more prudent to pursue the establishment of specific 
thresholds through formal consultation.
    This final rule does not explicitly state what might be included as 
special management for a particular river reach within the middle Rio 
Grande. We anticipate that special management actions will likely be 
developed as part of the section 7 consultation process. Special 
management might entail a suite of actions including re-establishment 
of hydrologic connectivity within the floodplain, widening the river 
channel, or placement of woody debris or boulders within the river 
channel (J. Smith, pers. comm., 2001).
    It is important to note that some areas within the middle Rio 
Grande critical habitat have the potential for periods of low or no 
flow under certain conditions (e.g., see discussion above on middle Rio 
Grande). We recognize that the critical habitat designation 
specifically includes some areas that have lost flow periodically 
(MRGCD 1999; Scurlock and Johnson 2001; Scurlock 1998). It is our 
belief that the river reach below San Acacia Diversion Dam on the 
middle Rio Grande is likely to experience periods of low or no flow 
under certain conditions, and we are not able to predict with certainty 
which areas will experience these conditions. We believe this area is 
essential to the conservation of the silvery minnow because it likely 
serves as connecting corridors for fish movements between areas of 
sufficient flowing water (e.g., see Deacon and Minckley 1974; Eberle et 
al. 1993). Additionally, we believe this area is essential for the 
natural channel geomorphology (the topography of the river channel) to 
maintain or re-create habitat, such as pools, by removing or 
redistributing sediment during high flow events (e.g., see Simpson et 
al. 1982; Middle Rio Grande Biological Interagency Team 1993). 
Therefore, we

[[Page 8117]]

believe that the inclusion of an area that has the potential for 
periods of low or no flow as critical habitat will ensure the 
conservation of the silvery minnow. As such, we believe that the 
primary constituent elements as described in this final rule could 
allow for short periods of low or no flow. Because of the difficulties 
in describing the existing conditions of this area (see above) and 
defining the primary constituent elements to reflect such a flow 
regime, we solicited comments in the proposed critical habitat 
designation rule for information related to the designation of critical 
habitat in this area that may experience periods of low or no flow, 
and, in particular, the primary constituent elements and how they 
related to the existing conditions (e.g., flow regime). We did not 
receive any additional information or comments on these areas to refine 
the primary constituent elements in this final designation.
    Federal agencies with discretion over water management actions that 
affect critical habitat will be required to consider critical habitat 
and possibly enter into consultation under section 7 of the Act. These 
consultations will evaluate whether any Federal discretionary actions 
destroy or adversely modify critical habitat to the extent that the 
action appreciably diminishes the value of the critical habitat for the 
survival and recovery of the species. The adverse modification analysis 
will likely evaluate whether the adverse effect of prolonged recurring 
periods of low or no flow is of sufficient magnitude (e.g., length of 
river) and duration that it would appreciably diminish the value of 
critical habitat for the survival and recovery of the silvery minnow. 
For example, the effect of prolonged periods of low or no flow on the 
habitat quality (e.g., depth of pools, water temperature, pool size) 
and the extent of fish mortality is related to the duration of the 
event (Bestgen and Platania 1991). All of these factors will be 
analyzed under section 7 of the Act, if they are part of an action 
proposed by a Federal agency. Additionally, any Federal agency whose 
actions influence water quantity or quality in a way that may affect 
critical habitat or the silvery minnow must enter into section 7 
consultation with us. Still, these consultations cannot result in 
biological opinions that require actions that are outside an action 
agency's legal authority and jurisdiction (50 CFR 402.02).
    We determined the primary constituent elements of critical habitat 
for the silvery minnow based on studies on their habitat and population 
biology, including, but not limited to the following studies: Bestgen 
and Platania 1991; Service 1999; Dudley and Platania 1997, 2001, 2002a; 
Platania and Altenbach 1998; Platania 1991, 2000; Service 2001; Smith 
1998, 1999; Hoagstrom 2000; Remshardt et. al 2001. The primary 
constituent elements are as follows:
    1. A hydrologic regime that provides sufficient flowing water with 
low to moderate currents capable of forming and maintaining a diversity 
of aquatic habitats, such as, but not limited to the following: 
Backwaters (a body of water connected to the main channel, but with no 
appreciable flow), shallow side channels, pools (that portion of the 
river that is deep with relatively little velocity compared to the rest 
of the channel), eddies (a pool with water moving opposite to that in 
the river channel), and runs (flowing water in the river channel 
without obstructions) of varying depth and velocity--all of which are 
necessary for each of the particular silvery minnow life-history stages 
in appropriate seasons. The silvery minnow requires habitat with 
sufficient flows from early spring (March) to early summer (June) to 
trigger spawning, flows in the summer (June) and fall (October) that do 
not increase prolonged periods of low or no flow, and a relatively 
constant winter flow (November through February);
    2. The presence of low-velocity habitat (including eddies created 
by debris piles, pools, or backwaters, or other refuge habitat (e.g., 
connected oxbows or braided channels)) within unimpounded stretches of 
flowing water of sufficient length (i.e., river miles) that provide a 
variety of habitats with a wide range of depth and velocities;
    3. Substrates of predominantly sand or silt; and
    4. Water of sufficient quality to maintain natural, daily, and 
seasonally variable water temperatures in the approximate range of 
greater than 1 [deg]C (35 [deg]F) and less than 30 [deg]C (85 [deg]F) 
and reduce degraded water quality conditions (decreased dissolved 
oxygen, increased pH, etc.).
    We determined that these primary constituent elements of critical 
habitat provide for the physiological, behavioral, and ecological 
requirements of the silvery minnow. The first primary constituent 
element provides water of sufficient flows to reduce the formation of 
isolated pools. We conclude this element is essential to the 
conservation of the silvery minnow because the species cannot withstand 
permanent drying (loss of surface flow) of long stretches of river. 
Water is a necessary component for all silvery minnow life-history 
stages and provides for hydrologic connectivity to facilitate fish 
movement. The second primary constituent element provides habitat 
necessary for development and hatching of eggs and the survival of the 
silvery minnow from larvae to adult. Low-velocity habitat provides 
food, shelter, and sites for reproduction, which are essential for the 
survival and reproduction of silvery minnow. The third primary 
constituent element provides appropriate silt and sand substrates 
(Dudley and Platania 1997; Remshardt et al. 2001), which we and other 
scientists conclude are important in creating and maintaining 
appropriate habitat and life requisites such as food and cover. The 
final primary constituent element provides protection from degraded 
water quality conditions. We conclude that when water quality 
conditions degrade (e.g., water temperatures are too high, pH levels 
are too low, and dissolved oxygen concentrations are too low), silvery 
minnows will likely be injured or die.

Criteria for Identifying Critical Habitat

    The primary objective in designating critical habitat is to 
identify areas that are considered essential for the conservation of 
the species, and to highlight specific areas where management 
considerations should be given highest priority. In determining 
critical habitat for the silvery minnow, we have reviewed the overall 
approach to the conservation of the silvery minnow undertaken by the 
local, State, Tribal, and Federal agencies operating within the 
species' historic range since the species' listing in 1994, and the 
previous proposed (March 1, 1993; 58 FR 11821) and final critical 
habitat rules (July 6, 1999; 64 FR 36274). We have also outlined our 
conservation strategy to recover the species (see ``Exclusions Under 
Section 4(b)(2) of the Act'' section above) and considered the features 
and steps necessary for recovery and habitat requirements described in 
the Recovery Plan (Service 1999). We considered information provided by 
our New Mexico Fishery Resources Office and other biologists, and also 
utilized our own expertise. We also reviewed the biological opinion 
issued June 29, 2001, to the BOR and the Corps for impacts to the 
silvery minnow from water operations in the middle Rio Grande (Service 
2001b), and the biological opinion issued to the BOR for discretionary 
actions related to water management on the Pecos River in NM (Service 
2001a). We reviewed available information that pertains to the habitat 
requirements of this species, including material received during the 
initial

[[Page 8118]]

public comment period on the proposed listing and designation, the 
information received following the provision of the draft economic 
analysis to the public on April 26, 1996, the comments and information 
provided during the 30-day comment period that opened on April 7, 1999, 
including the public hearing, and the comments and information received 
during the 60-day comment period opened on April 5, 2001, for the 
notice of intent to prepare an EIS and public scoping meetings held on 
April 17, 23, 24, and 27, 2001 (April 7, 1999; 64 FR 16890). We also 
considered information and comments received on the recent proposal to 
designate critical habitat (June 6, 2002; 67 FR 39206).
    Since the listing of the silvery minnow in 1994 (July 20, 1994; 59 
FR 36988), no progress has been made toward reestablishing this species 
within unoccupied areas (e.g., river reaches on the middle Pecos, lower 
Rio Grande). Because the silvery minnow has been extirpated from these 
areas, Federal agencies have not consulted with us on how their 
discretionary actions may affect the silvery minnow. We conclude these 
areas (e.g., river reaches on the middle Pecos and the lower Rio 
Grande) are essential to the conservation of the minnow, but we have 
not designated them as critical habitat (see ``Exclusions Under Section 
4(b)(2) of the Act'' section).
    This critical habitat designation differs from the final critical 
habitat designation we made in 1999 (July 6, 1999; 64 FR 36274), which 
was subsequently set aside by court order. The differences also reflect 
the best scientific and commercial information analyzed in the context 
of the final Recovery Plan (see ``Recovery Plan'' discussion above) and 
our conservation strategy for this species. Although we could have 
designated two additional critical habitat units to respond to the 
Recovery Plan's recommendation that additional areas are required to 
achieve recovery (Service 1999) (see ``Recovery Plan'' discussion 
above), we believe that inclusion of these areas under a critical 
habitat regulation could hinder our future conservation strategy (see 
``Exclusions Under Section 4(b)(2) of the Act'' section above) and 
actually impede recovery of the silvery minnow.
    Recovery requires protection and enhancement of existing 
populations and reestablishment of populations in suitable areas of 
historic range. The Recovery Plan identifies ``the necessity of 
reestablishing silvery minnow in portions of its historic range outside 
of the middle Rio Grande in New Mexico.'' The Recovery Plan identified 
potential areas for reestablishment of silvery minnow in certain river 
reaches of the Rio Grande and Pecos River. The Recovery Plan also 
recommended a thorough analysis of the reestablishment potential of 
specific river reaches within the historic range of the silvery minnow.
    We have determined that one of the most important goals to be 
achieved toward the conservation of this species is the establishment 
of secure, self-reproducing populations in areas outside of the middle 
Rio Grande, but within the species' historic range (Service 1999). 
Thus, we have outlined our conservation strategy for the silvery minnow 
(see ``Exclusions Under Section 4(b)(2) of the Act'' section above). 
Because the species occupies less than 5 percent of its historic range 
and the likelihood of extinction from a catastrophic event is greatly 
increased (Hoagstrom and Brooks 2000; Service 1999), we believe that 
additional populations should be established within certain unoccupied 
reaches (i.e., areas outside of the current known distribution). 
Nevertheless, any future recovery efforts, including reintroduction of 
the species to areas of its historic range, must be conducted in 
accordance with NEPA and the Act.
    The recent trend in the status of the silvery minnow has been 
characterized by dramatic declines in numbers and range despite the 
fact that this species evolved in rapidly fluctuating, harsh 
environments. Moreover, none of the threats affecting the silvery 
minnow has been eliminated since the fish was listed (July 20, 1994; 59 
FR 36988), and its status continues to decline (Dudley and Platania 
2001, 2002b, 2002c, 2002d, 2002e). The known silvery minnow population 
within the middle Rio Grande has become fragmented and isolated and is 
vulnerable to those natural or manmade factors that might further 
reduce population size (Dudley and Platania 2001, 2002a, 2002b). 
Because there have been low spring peak flows in the Rio Grande in some 
recent years (e.g., 2000) and a related decrease in silvery minnow 
spawning success, the population size of silvery minnow continued to 
decline through the winter of 2002 (Dudley and Platania 2001, 2002a, 
2002b, 2002c, 2002d, 2002e). We conclude that the species' 
vulnerability to catastrophic events, such as prolonged periods of low 
or no flow, has increased since the species was listed as endangered in 
1994 (July 20, 1994; 59 FR 36988).
    It is widely recognized that major efforts to reintroduce the 
silvery minnow to large reaches of its historic habitat in the Rio 
Grande and Pecos River will not likely occur without either natural or 
induced changes in the river, including changes affecting the existing 
fish community, habitat restoration, and coordinated water management 
(e.g., Service 1999). Nevertheless, we conclude that conservation of 
the silvery minnow requires habitat conditions that will facilitate 
population expansion or reintroduction. As an example, we are currently 
involved in developing several efforts to assist in the recovery of the 
silvery minnow and other imperiled species (e.g., Federal and non-
Federal efforts to create a middle Rio Grande Endangered Species Act 
Collaborative Program). Any future habitat restoration efforts 
conducted by us or other Federal agencies within the species' historic 
habitat will be analyzed through NEPA and will be conducted in 
accordance with the pertinent sections of the Act and Federal 
rulemaking procedures.
    As discussed above in the comments section, non-native fish species 
may adversely affect the silvery minnow. However, non-native fish have 
the potential to be removed or reduced to acceptable levels using a 
variety of control or management techniques. For example, the New 
Mexico State Game Commission recently passed a regulation limiting the 
species that can be used as baitfish in the Pecos River (New Mexico 
Department of Game and Fish 2000). As part of the Federal rulemaking 
process, we sought further information regarding the role of unoccupied 
river reaches within the historic range of the silvery minnow, 
including those reaches with non-native fish species (e.g., plains 
minnow) present or those reaches that have the potential for low or no 
flow events. We were particularly interested in assistance in 
describing the existing habitat (e.g., flow) conditions for the river 
reach below San Acacia Diversion Dam on the middle Rio Grande. However, 
we did not receive additional information on these areas to refine this 
final designation.
    It is important to note that the mere presence of non-native 
aquatic species does not eliminate an area from being considered for 
designation as critical habitat. For example, the relationship between 
the introduction of the plains minnow and extirpation of the silvery 
minnow is unclear (see discussion above). Although the Recovery Plan 
suggested that the plains minnow would be the primary limiting factor 
precluding successful reestablishment of the silvery minnow to the 
Pecos River (Service 1999), we have little data from which to draw firm 
conclusions for the extirpation of the silvery minnow from the Pecos 
River. We recognize that any efforts to reestablish the silvery minnow

[[Page 8119]]

to unoccupied river reaches must fully analyze and consider a variety 
of habitat management techniques, including the control or management 
of non-native fish. Consequently, we invited comments or information 
relating to the status of the plains minnow in the Pecos River and this 
area not being proposed as critical habitat. We were especially 
interested in observations of related species of Hybognathus and any 
behavioral or reproductive mechanisms that might provide for ecological 
separation in areas where two or more species of Hybognathus co-occur. 
We did not receive any additional information concerning this aspect of 
the designation.
    Portions of the Pecos River include designated critical habitat for 
the Pecos bluntnose shiner (52 FR 5295). The Pecos bluntnose shiner 
critical habitat includes a 64 mi (103 km) reach of the Pecos River 
extending from a point 10 mi (16 km) south of Fort Sumner, NM, 
downstream to the De Baca and Chaves County line and a 37 mi (60 km) 
reach from near Hagerman, NM, to near Artesia, NM (52 FR 5295). There 
are current protections in place for the Pecos bluntnose shiner in the 
river reach from Sumner to Brantley Reservoirs on the Pecos River; 
consequently, we believe that the designation of critical habitat would 
provide little additional benefit for the silvery minnow above the 
current jeopardy and adverse modifications standards for the Pecos 
bluntnose shiner (see ``Exclusions Under Section 4(b)(2) of the Act'' 
section above).
    The Pecos bluntnose shiner inhabits main-channel habitats with 
sandy substrates, low-velocity flows, and depths from 17 to 41 cm (7 to 
16 in) (Hatch et al. 1985). Adult Pecos bluntnose shiners use main-
channel habitats, with larger individuals found mainly in more rapidly 
flowing water (greater than 40 cm/sec, 1.25 ft/sec), but preferences 
for particular depths were not found (Hoagstrom et al. 1995). Young of 
the year use the upstream reaches between Sumner and Brantley 
Reservoirs, which provide shallow, low-velocity habitat. These reaches 
also maintain such habitat at high (bankfull) discharge, providing 
refugia from swift, deep water. Pecos bluntnose shiner and related 
mainstream cyprinids (e.g., silvery minnow) are adapted to exploit 
features of Great Plains rivers (Hoagstrom 2000). These fish species 
belong to the same guild of broadcast spawners with semibuoyant eggs 
and also spawn during high flow events in the Pecos River, with eggs 
and larvae being distributed downstream to colonize new areas (Bestgen 
et al. 1989). The habitat features used by the Pecos bluntnose shiner 
are largely affected by ongoing Sumner Dam operations (e.g., block 
releases). Nevertheless, any flow regime operations in this reach that 
benefit the Pecos bluntnose shiner would also benefit the silvery 
minnow. We believe they could both occupy the same river reach in the 
future with little to no interspecific competition, in part because 
these species historically coexisted (Bestgen and Platania 1991) and 
microhabitat partitioning has been documented for related species of 
southwestern fish (Matthews and Hill 1980). Therefore, we believe that 
the primary constituent elements for the Pecos bluntnose shiner 
critical habitat (e.g., clean permanent water; a main river channel 
habitat with sandy substrate; and a low velocity flow (February 20, 
1987; 52 FR 5295)) are compatible with our conservation strategy for 
repatriating the silvery minnow.

Lateral Extent of Critical Habitat

    The critical habitat designation defines the lateral extent as 
those areas bounded by existing levees, or in areas without levees, the 
lateral extent of critical habitat is defined as 300 ft (91.4 m) of 
riparian zone adjacent to each side of the middle Rio Grande. Thus, the 
lateral extent of critical habitat does not include areas adjacent to 
the existing levees but within the 300-ft (91.4-m) lateral width 
outside the existing levees (i.e., these areas are not designated as 
critical habitat, even though they may be within the 300-ft lateral 
width). This designation of critical habitat will not remove existing 
levees. We recognize that these areas can be important for the overall 
health of river ecosystems, but these areas have almost no potential 
for containing the primary constituent elements because they are 
separated from the river by the levees and are rarely inundated by 
water. Therefore, they are not included in the designation because we 
conclude they are not essential to the conservation of the silvery 
minnow. Nevertheless, these and other areas outside the critical 
habitat designation will continue to be subject to conservation actions 
that may be implemented under section7(a)(1) of the Act, the regulatory 
protections afforded by the jeopardy standard in section 7(a)(2) of the 
Act, and take prohibitions in section 9 of the Act.
    For each river reach within the middle Rio Grande, the upstream and 
downstream boundaries are described below. Critical habitat includes 
the river channels within the identified reaches and areas within these 
reaches potentially inundated during high-flow events. Critical habitat 
includes the area of bankfull width plus 300 ft (91.4 m) on either side 
of the banks. The bankfull width is the width of the stream or river at 
bankfull stage (i.e., the flow at which water begins to leave the 
channel and move into the floodplain (Rosgen 1996)). Bankfull stage, 
while a function of the size of the stream, is a fairly consistent 
feature related to the formation, maintenance, and dimensions of the 
stream channel (Rosgen 1996). This 300-ft (91.4-m) width defines the 
lateral extent of those areas we believe are essential to the species' 
conservation. Although the silvery minnow cannot be found in these 
areas when they are dry, these areas likely provided backwater habitat 
and were sometimes flooded in the past (Middle Rio Grande Biological 
Interagency Team 1993); therefore, they may provide habitat during 
high-water periods. As discussed in this section, we determined that 
the areas within the 300-ft (91.4-m) lateral width are essential to the 
conservation of the silvery minnow.
    We determined the 300-ft (91.4-m) lateral extent for several 
reasons. First, the implementing regulations of the Act require that 
critical habitat be defined by reference points and lines as found on 
standard topographic maps of the area (50 CFR 424.12). Although we 
considered using the 100-year floodplain, as defined by the Federal 
Emergency Management Agency (FEMA), we found that it was not included 
on standard topographic maps, and the information was not readily 
available from FEMA or from the Corps for the areas we are designating. 
We suspect this is related to the remoteness of various river reaches. 
We received comments in relation to other sources of information (e.g., 
National Wetlands Inventory maps) to refine the lateral extent of 
critical habitat (see comments section above). After evaluating this 
information, we concluded that our designation accurately delineates 
the boundary of critical habitat. We selected the 300-ft (91.4-m) 
lateral extent, rather than some other delineation, for three reasons: 
(1) The biological integrity and natural dynamics of the river system 
are maintained within this area (i.e., the floodplain and its riparian 
vegetation provide space for natural flooding patterns and latitude for 
necessary natural channel adjustments to maintain appropriate channel 
morphology and geometry, store water for slow release to maintain base 
flows, provide protected side channels and other protected areas for 
larval and juvenile silvery minnow, allow the river to meander within 
its

[[Page 8120]]

main channel in response to large flow events, and recreate the mosaic 
of habitats necessary for the conservation of the silvery minnow); (2) 
conservation of the adjacent riparian zone also helps provide essential 
nutrient recharge and protection from sediment and pollutants, which 
contributes to successful spawning and recruitment of silvery minnows; 
and (3) vegetated lateral zones are widely recognized as providing a 
variety of aquatic habitat functions and values (e.g., aquatic habitat 
for fish and other aquatic organisms, moderation of water temperature 
changes, and detritus for aquatic food webs) and help improve or 
maintain local water quality (March 9, 2000; 65 FR 12897; Middle Rio 
Grande Biological Interagency Team 1993).
    This critical habitat designation takes into account the naturally 
dynamic nature of riverine systems and recognizes that floodplains 
(including riparian areas) are an integral part of the stream 
ecosystem. For example, riparian areas are seasonally flooded habitats 
(i.e., wetlands) that are major contributors to a variety of vital 
functions within the associated stream channel (Federal Interagency 
Stream Restoration Working Group 1998, Brinson et al. 1981). They are 
responsible for energy and nutrient cycling, filtering runoff, 
absorbing and gradually releasing floodwaters, recharging groundwater, 
maintaining streamflows, protecting stream banks from erosion, and 
providing shade and cover for fish and other aquatic species. Healthy 
riparian areas help ensure water courses maintain the habitat 
components essential to aquatic species (e.g., see U.S.D.A. Forest 
Service 1979; Middle Rio Grande Biological Interagency Team 1993; 
Briggs 1996), including the silvery minnow. Habitat quality within the 
mainstem river channels in the historic range of the silvery minnow is 
intrinsically related to the character of the floodplain and the 
associated tributaries, side channels, and backwater habitats that 
contribute to the key habitat features (e.g., substrate, water quality, 
and water quantity) in the middle Rio Grande (Middle Rio Grande 
Biological Interagency Team 1993). Among other things, the floodplain 
provides space for natural flooding patterns and latitude for necessary 
natural channel adjustments to maintain channel morphology and 
geometry. We believe a relatively intact riparian area, along with 
periodic flooding in a relatively natural pattern, is important in 
maintaining the stream conditions necessary for long-term conservation 
of the silvery minnow.
    Human activities that occur outside the river channel can have a 
demonstrable effect on physical and biological features of aquatic 
habitats. However, not all of the activities that occur within a 
floodplain will have an adverse impact on the silvery minnow or its 
habitat. Thus, in determining the lateral extent of critical habitat 
along riverine systems, we must consider the definition of critical 
habitat under the Act. That is, critical habitat must be determined to 
be essential to a species' conservation and, within areas currently 
occupied by the species, must be in need of special management 
considerations or protection.
    We do not believe that the entire floodplain is essential to the 
conservation of the species, and we are not proposing to designate the 
entire floodplain as critical habitat. However, the river channel alone 
is not sufficient to ensure the conservation of the silvery minnow. For 
the reasons discussed above, we believe that the riparian zone adjacent 
to the river channel provides an important function for the protection 
and maintenance of the primary constituent elements and is essential to 
the conservation of the species.
    The lateral extent (width) of riparian corridors fluctuates 
considerably on the Rio Grande. The appropriate width for riparian 
protection has been the subject of several studies (Castelle et al. 
1994). Most Federal and State agencies generally consider a zone 23 to 
46 m (75.4 to 150.9 ft) wide on each side of a stream to be adequate to 
help improve or maintain local water quality (Natural Resource 
Conservation Service 1998, 2000; Lynch et al. 1985), although lateral 
widths as wide as 152 m (500 ft) have been recommended for achieving 
flood attenuation benefits (Corps 1999). In most instances, however, 
these riparian areas are primarily intended to reduce detrimental 
impacts to the stream (i.e., protect the stream) from sources outside 
the river channel such as agricultural runoff. Generally, we believe a 
lateral distance of 300 ft (91.4 m) on each side of the stream beyond 
the bankfull stage to be appropriate for the protection of riparian and 
wetland habitat and the natural processes involved in the maintenance 
and improvement of water quality (e.g., see Middle Rio Grande 
Biological Interagency Team 1993). We believe this lateral width will 
help ensure the protection of one or more primary constituent elements 
(e.g., water quality) of the critical habitat. Thus, within the area 
designated as critical habitat in the middle Rio Grande, we conclude 
that the 300-ft (91.4-m) lateral width is essential to the conservation 
of the species.
    We did not map critical habitat in sufficient detail to exclude all 
developed areas and other lands unlikely to contain primary constituent 
elements essential for silvery minnow conservation. Some developed 
lands within the 300-ft (91.4-m) lateral extent are not considered 
critical habitat because they do not contain the primary constituent 
elements and they are not essential to the conservation of the silvery 
minnow. Lands located within the exterior boundaries of the critical 
habitat designation, but not considered critical habitat, include: 
Developed flood control facilities; existing paved roads; bridges; 
parking lots; dikes; levees; diversion structures; railroad tracks; 
railroad trestles; water diversion and irrigation canals outside of 
natural stream channels; the low flow conveyance channel; active gravel 
pits; cultivated agricultural land; and residential, commercial, and 
industrial developments. These developed areas do not contain any of 
the primary constituent elements and do not provide habitat or 
biological features essential to the conservation of the silvery 
minnow. However, some activities in these areas, like activities in 
other areas not included within the designation (if Federally funded, 
authorized, or carried out), may affect the primary constituent 
elements of the critical habitat and, therefore, may be affected by the 
critical habitat designation, as discussed later in this rule.

Reach-by-Reach Analysis

    We conducted a reach-by-reach analysis of the entire known historic 
range of the silvery minnow to evaluate and select river reaches that 
require special management or protection, or are essential to the 
conservation of the species. As identified in the Recovery Plan (see 
``Recovery Plan'' section above), important factors we considered in 
determining whether areas were essential to the conservation of the 
species include presence of other members of the reproductive guild 
(e.g. pelagic spawners, species with semibuoyant eggs), habitat 
suitability (e.g., appropriate substrate), water quality, and presence 
of non-natives (e.g., competitors, predators, other species of 
Hybognathus). These important factors were evaluated in conjunction 
with the variable flow regime of each reach. Each of the river reaches, 
to some extent, has a varying flow regime. However, the fact that a 
river reach may at times experience a prolonged period of low or no 
flow as

[[Page 8121]]

a result of a varying flow regime does not preclude the area from being 
considered essential to the conservation of the species and, further, 
from being designated as critical habitat. Based on our reach-by-reach 
analysis, we have determined which reaches are essential for the 
conservation of the species.
    We are designating the middle Rio Grande as critical habitat. This 
area contains all of the primary constituent elements during some or 
all of the year (see the ``Regulation Promulgation'' section of this 
rule for exact descriptions of boundaries of designated critical 
habitat). We conclude that this critical habitat can provide for the 
physiological, behavioral, and ecological requirements of the silvery 
minnow. The designated critical habitat is within the middle Rio Grande 
from immediately downstream of Cochiti Reservoir to the utility line 
crossing the Rio Grande with UTM coordinates of UTM Zone 13: 311474 E, 
3719722N, just east of the Bosque Well demarcated on USGS Paraje Well 
7.5 minute quadrangle (1980), including the tributary Jemez River from 
Jemez Canyon Dam to the upstream boundary of Santa Ana Pueblo, which is 
not included. The designation also defines the lateral extent (width) 
as those areas bounded by existing levees or, in areas without levees, 
300 ft (91.4 m) of riparian zone adjacent to each side of the bankfull 
stage of the middle Rio Grande. We did not include the Pueblo lands of 
Santo Domingo, Santa Ana, Sandia, and Isleta within the middle Rio 
Grande. The downstream boundary of the designated critical habitat is 
determined to be the utility line crossing (see the ``Regulation 
Promulgation'' section of this rule for exact descriptions of 
boundaries of designated critical habitat). Although we determined that 
other areas are essential to the conservation of the silvery minnow 
(i.e., the middle Pecos River from immediately downstream of Sumner Dam 
to Brantley Dam, NM, and the lower Rio Grande from the upstream 
boundary of Big Bend National Park to Terrell/Val Verde County line, 
TX), these areas are not designated as critical habitat. A description 
of each river reach within the silvery minnow's historic range is 
provided below. We also provide our reasons for determining whether 
each reach is essential to the conservation of the species and whether 
we are designating critical habitat for each of the identified reaches. 
We conclude that we can secure the long-term survival and recovery of 
this species with the establishment of future experimental populations 
under section 10(j) of the Act, along with the critical habitat in the 
middle Rio Grande.
    The historic range of the species in the Rio Grande is from 
Espanola, NM, to the Gulf of Mexico, and in the Pecos River (a major 
tributary of the Rio Grande) from Santa Rosa, NM, downstream to its 
confluence with the Rio Grande (Pflieger 1980; Bestgen and Platania 
1991). We separated the historic range of the silvery minnow into 12 
river reaches: (1) Upstream of Cochiti Reservoir to the confluence of 
the Rio Chama and Rio Grande, NM; (2) middle Rio Grande from Cochiti 
Reservoir downstream to the Elephant Butte Dam, including the Jemez 
River from the Jemez Canyon Dam to the confluence of the Rio Grande; 
(3) downstream of Elephant Butte Dam to the Caballo Dam, NM; (4) 
downstream of Caballo Dam, New Mexico, to the American Dam, TX; (5) 
downstream of American Reservoir, to the upstream boundary of Big Bend 
National Park, TX; (6) the upstream boundary of Big Bend National Park 
to the southern boundary of the wild and scenic river designation at 
Terrell/Val Verde County line, TX; (7) the Terrell/Val Verde County 
line, TX, to the Amistad Dam, TX; (8) downstream of Amistad Dam to the 
Falcon Dam, TX; (9) downstream of the Falcon Dam to the Gulf of Mexico, 
TX; (10) Pecos River from Santa Rosa Reservoir to Sumner Dam, Guadalupe 
County, NM; (11) Sumner Dam to the Brantley Dam, NM; (12) Brantley Dam, 
NM, to the Red Bluff Dam, TX; and (13) Red Bluff Dam to the confluence 
of the Rio Grande, TX. Each of these reaches is analyzed below.
    1. Upstream of Cochiti Reservoir to the confluence of the Rio Chama 
and Rio Grande, Rio Arriba, Sante Fe, and Sandoval Counties, NM. 
Currently, this reach is dominated by cool water, which is not 
considered suitable for the silvery minnow (Platania and Altenbach 
1998). The majority of this reach is bounded by canyons, with substrate 
dominated by gravel, cobble, and boulder (Service 1999). The flow 
regime is also highly variable seasonally because of irrigation and 
other agricultural needs, as well as recreational and municipal uses. 
This river reach is highly manipulated by releases from El Vado and 
Abiquiu Reservoirs (J. Smith, pers. comm. 2001). Furthermore, silvery 
minnow populations may have been historically low for some areas of 
this reach, supporting only small outlier populations (Bestgen and 
Platania 1991). Currently, this reach is dominated by cool or cold 
water species, which have almost completely replaced the native fish 
species (Service 1999). The stream length in this reach is inadequate 
(e.g., less than 134 to 223 mi ( 216 to 358.8 km)) to ensure the 
survival of downstream drift of eggs and larvae and recruitment of 
adults (Platania and Altenbach 1998). Further investigation may be 
needed in this reach to evaluate potential future recovery actions. For 
these reasons, we conclude that habitat for silvery minnow within this 
river reach is generally degraded and unsuitable, and is not essential 
to the conservation of the silvery minnow. Therefore, this river reach 
is not designated as critical habitat.
    2. Middle Rio Grande from Cochiti Reservoir downstream to the 
Elephant Butte Dam, including the Jemez River from the Jemez Canyon Dam 
to the confluence of the Rio Grande, Sandoval, Bernalillo, Valencia, 
and Socorro Counties, NM. The middle Rio Grande is currently occupied, 
and the status of the silvery minnow within this segment is unstable 
(Bestgen and Platania 1991; Dudley and Platania 1999; Platania and 
Dudley 2001; 2002a, 2002b). This area currently contains the primary 
constituent elements (described above) during all or part of the year 
and is considered suitable habitat for the silvery minnow, as shown by 
the presence of the silvery minnow within this reach. The river reaches 
that are designated as critical habitat are degraded from lack of 
floodplain connectivity, non-native vegetation, stabilized banks (e.g., 
jetty jacks), streambed aggradation, and decreasing channel width, 
increasing depths, and increasing velocities (BOR 2001a; Service 
2001b). Thus, conservation of the silvery minnow requires stabilizing 
populations within the middle Rio Grande, including special management 
considerations or protections (e.g., habitat management and/or 
restoration).
    The middle Rio Grande is essential to the conservation of the 
silvery minnow (see discussion below), and therefore, except for the 
land of Santo Domingo, Santa Ana, Sandia, and Iselta Pueblos, we 
designate the following reaches as a critical habitat. This designated 
critical habitat does not include the ephemeral or perennial irrigation 
canals and ditches, including the LFCC (i.e., downstream of the 
southern boundary of Bosque del Apache National Wildlife Refuge to the 
headwaters of Elephant Butte Reservoir) that are adjacent to a portion 
of the river reach within the middle Rio Grande because these areas do 
not offer suitable refugia for the silvery minnow. The river reaches in 
the middle Rio Grande critical habitat include (see ``Regulation 
Promulgation'' section of this rule for exact

[[Page 8122]]

descriptions of boundaries of designated critical habitat):
    a. Jemez Canyon Reach--5 mi (8 km) of the Jemez River from the 
Jemez Canyon Dam to the upstream boundary of Santa Ana Pueblo, which is 
not included. This reach of river is manipulated by releases from Jemez 
Canyon Dam. Releases from this reservoir are determined by downstream 
needs and flood events occurring in the Jemez River. Silvery minnows 
historically occupied this reach of the Jemez River and have recently 
been collected there (Sublette et al. 1990; Corps 2001). The water 
within this reach is continuous to the confluence with the Rio Grande 
and currently contains the primary constituent elements (described 
above) during all or a part of the year. Although this reach currently 
provides suitable habitat for the silvery minnow, we believe that it is 
important to ensure that special management actions are implemented 
within this river reach. We also conclude that this area is essential 
to the conservation of the silvery minnow, because the additional loss 
of any habitat that is currently occupied could increase the likelihood 
of extinction (Hoagstrom and Brooks 2000, Service 1999). Moreover, if 
the species or habitat were severely impacted within this reach, the 
continued existence of silvery minnows in downstream reaches would be 
affected (i.e., the extirpation of fish within this reach would create 
a very unstable population within the downstream reaches). Thus, we 
designate the upstream section of the Jemez River as critical habitat 
for the silvery minnow.
    b. Cochiti Reservoir Dam to Angostura Diversion Dam (Cochiti 
Reach)--21 mi (34 km) of river immediately downstream of Cochiti 
Reservoir to the Angostura Diversion Dam, not including the lands of 
Santo Domingo Pueblo. This reach is somewhat braided and is dominated 
by clear water releases from Cochiti Reservoir (Richard 2001). Since 
Cochiti Reservoir was filled, the downstream substrate has changed from 
a coarse sand to a gravel/cobble/sand substrate (Hoagstrom and Brooks 
2000; Baird 2001; Richard 2001). Silvery minnows were collected 
immediately downstream of Cochiti Dam in 1988 (Platania 1993). Although 
the Cochiti reach has not been monitored since the mid-1990s (Platania 
1995; Hoagstrom and Brooks 2000), it is believed that silvery minnow 
may still be present within this reach, but reduced in abundance (e.g., 
Dudley and Platania 2002a). For example, silvery minnows were 
documented near the Angostura Diversion Dam in 2001 (Platania and 
Dudley 2001, 2002a; Service 2001c). In this reach, water releases from 
Cochiti Reservoir have scoured sand from the stream channel and reduced 
the downstream temperatures (Bestgen and Platania 1991; Platania 1991; 
(July 20, 1994) 59 FR 36988; Service 1999; Hoagstrom 2000). These 
effects (e.g., low water temperatures) may inhibit or prevent 
reproduction among Rio Grande Basin cyprinids (minnows) (Platania and 
Altenbach 1998), but it is unknown if water temperatures have affected 
silvery minnow reproduction within this reach. Although reservoirs can 
modify river flows and habitat (e.g., the downstream river reaches have 
increased in depth and water velocity) (Hoagstrom 2000), we believe 
this river reach is essential to the conservation of the silvery minnow 
because we believe it is still occupied by the species and contributes 
to its survival in downstream reaches (because the eggs and larvae of 
the silvery minnow drift in the water column and may be transported 
downstream depending on river flows and habitat conditions). We 
reviewed aerial photographs from 1997 and other information, and have 
determined that the river through this reach is braided in areas and 
contains many side channels (e.g., Richard 2001). We also spoke with 
the Corps and have concluded that there is a high potential to increase 
the amount of suitable habitat (e.g., debris piles, low velocity 
backwaters, side channels) within the entire reach, but particularly in 
the proximity of the confluences of Galisteo Creek and the Rio Grande 
and the Sante Fe River and the Rio Grande (D. Kreiner, U.S. Army Corps 
of Engineers, pers. comm. 2001). Thus, we conclude special management 
is needed in this reach. We conclude that this area contains suitable 
habitat for the silvery minnow and contains the primary constituent 
elements (described above) during all or part of the year. Therefore, 
this reach is designated as critical habitat.
    c. Angostura Diversion Dam to Isleta Diversion Dam (Angostura 
Reach)--38 mi (61 km) (of river immediately downstream of the Angostura 
Diversion Dam to the Isleta Diversion Dam, not including the lands of 
Santa Ana and Sandia Pueblos. Silvery minnows and suitable habitat are 
still present throughout this reach of the river, although their 
abundance appears to be low (Dudley and Platania 2001, 2002a, 2002b; 
Service 2002). This reach is relatively wide at 183 m (600 ft) and the 
substrate is mostly coarse sand to gravel (Baird 2001). The river bank 
within this reach is dominated by bank stabilization (e.g., jetty 
jacks), which has led to the floodplain being predominantly 
disconnected from the river. Bank stabilization devices and other flood 
control operations (e.g., channelization) have led to flows that seldom 
exceed channel capacity, such that the river dynamics that likely 
provided backwater habitat for the silvery minnow no longer function 
naturally. These river processes historically shaped and reshaped the 
river, constantly redefining the physical habitat and complexity of the 
river. Historical large flow events allowed the river to meander, 
thereby creating and maintaining the mosaic of habitats necessary for 
the survival of the silvery minnow and other native fish (Middle Rio 
Grande Biological Interagency Team 1993). We conclude that the creation 
and maintenance of these habitats is essential to the conservation of 
the silvery minnow. We believe that special management is necessary in 
this and other downstream reaches within the middle Rio Grande to 
create and maintain the habitat complexity (e.g., backwater areas, 
braided channels) that was historically present but may not be 
currently present in these river reaches. This reach currently contains 
the primary constituent elements (described above) during all or a part 
of the year. Thus, we designate this reach as critical habitat.
    d. Isleta Diversion Dam to San Acacia Diversion Dam (Isleta 
Reach)--56 mi (90 km) of river downstream of the Isleta Diversion Dam 
to the San Acacia Diversion Dam, not including the lands of Isleta 
Pueblo. The river bank within this reach is also dominated by bank 
stabilization (e.g., jetty jacks), and the floodplain is predominantly 
disconnected from the river. The substrate is mostly sand and silt and 
there are many permanent islands within the river channel (J. Smith, 
pers. comm. 2001). This reach provides continuous water flow in most 
years with infrequent periods of low or no flow (Service 2001b). 
Nevertheless, flows vary markedly in magnitude, from high spring to low 
summer flows. The variable flow regime is a result of irrigation 
demand, irrigation returns (e.g., augmented flow), precipitation, 
temperature, and sediment transport. This reach also contains numerous 
arroyos and small tributaries that provide water and sediment during 
rainstorm events, which may periodically augment river flows (Service 
2001b; J. Smith, pers. comm. 2001). Silvery minnows and suitable 
habitat are still present throughout this reach of the river; however, 
abundance

[[Page 8123]]

appears to be low (Dudley and Platania 2001, 2002a, 2002b; Service 
2002). Nevertheless, we conclude that this area is essential to the 
conservation of the silvery minnow because the additional loss of any 
habitat that is currently occupied could increase the likelihood of 
extinction (Hoagstrom and Brooks 2000, Service 1999). Similarly, if the 
species or habitat were severely impacted within this reach, the 
continued existence of silvery minnows in downstream reaches would be 
affected (i.e., the extirpation of fish within this reach would create 
a very unstable population within the downstream reaches). This reach 
currently contains the primary constituent elements (described above) 
during all or part of the year. We believe that special management is 
necessary within this reach to create and maintain the habitat 
complexity (e.g., backwater areas, debris piles, meandering river) that 
was historically but may not be currently be present within this reach. 
Thus, we designate this reach as critical habitat.
    e. San Acacia Diversion Dam to the utility line crossing the Rio 
Grande with UTM coordinates of UTM Zone 13: 311474 E, 3719722 N, near 
Elephant Butte Reservoir (San Acacia Reach)--9 mi (14.5 km) of river 
immediately downstream of the San Acacia Diversion Dam to the utility 
line crossing the Rio Grande with UTM coordinates of UTM Zone 13: 
311474 E, 3719722N. The channel width within this reach varies from 
approximately 15 m (50 ft) to approximately 198 m (650 ft). The 
substrate is mostly sand and silt. The flow regime within this reach 
was historically, and is currently highly variable. In fact, this 
stretch may not have provided continuous flow in some years prior to 
the 1900s (MRGCD 1999; Scurlock and Johnson 2001).
    Currently, the river channel has been highly modified by water 
depletions from agricultural and municipal use, dams and water 
diversion structures, bank stabilization, and the infrastructure for 
water delivery (e.g., irrigation ditches). These modifications have led 
to the loss of sediment, channel drying, separation of the river from 
the floodplain, and changes in river dynamics and resulting channel 
morphology. Consequently, this reach requires special management 
considerations similar to those discussed above. This reach currently 
contains the primary constituent elements (described above) during all 
or a part of the year. Although the silvery minnow continues to be 
widespread within this reach with higher abundance than the Angostura 
or Isleta reaches (Dudley and Platania 2001, 2002a, 2002b), the 
variable flow regime and modifications to the river have increased the 
potential for short- and long-term impacts not only to the silvery 
minnow, but also to its habitat. Thus, we determine that this area is 
essential to the conservation of the species and in need of special 
management considerations or protections; we designate this reach as 
critical habitat.
    3. Downstream of Elephant Butte Reservoir to the Caballo Dam, 
Sierra County, NM. This short 16-mi (26-km) reach is highly channelized 
with widely variable flow regimes. Construction of Elephant Butte and 
Caballo Reservoirs in 1916 and 1938, respectively, severely altered the 
flows and habitat within this reach (Bestgen and Platania 1991). The 
silvery minnow has not been documented within this reach since 1944 
(Service 1999). This river reach is currently highly channelized to 
expedite water deliveries and very few native fish remain (Propst et 
al. 1987; International Boundary and Water Commission 2001). This reach 
is subject to prolonged periods of low or no flow and there is no 
spring runoff spike (Service 1999). Altered flow regimes will continue 
to affect habitat quality in this reach, which does not contain 
suitable habitat for the silvery minnow. The stream length in this 
reach is inadequate (e.g., less than 134 to 223 mi (216 to 358.8 km )) 
to ensure the survival of downstream drift of eggs and larvae and 
recruitment of adults (Platania and Altenbach 1998). We conclude this 
area is not essential to the conservation of the species. Therefore, 
this river reach is not designated as critical habitat.
    4. Downstream of Caballo Dam to American Reservoir Dam, Sierra and 
Dona Ana Counties, NM, and El Paso, County, TX. This approximately 110-
mi (176-km) reach has a highly regulated flow regime from releases of 
water stored in Caballo Reservoir. This reach is also highly 
channelized with winter flows near zero in the upper portions, and does 
not contain suitable habitat for the silvery minnow (Service 1999; IBWC 
2001a). Silvery minnows have not been reported from this reach since 
1944 (Bestgen and Platania 1991, Service 1999). The reach is currently 
inhabited by many non-native fish species (IBWC 2001a). Due to lack of 
suitable habitat, and diminished and highly regulated flow (IBWC 
2001a), this reach of river no longer contains suitable habitat for the 
silvery minnow and is not essential to the conservation of the species. 
Thus, this reach is not designated as critical habitat.
    5. Downstream of American Reservoir to the upstream boundary of Big 
Bend National Park, El Paso, Hudspeth, and Presidio, Counties, TX. 
Portions of this reach, primarily upstream of Presido, TX, are 
continually dewatered, especially between Fort Quitman and Presidio 
(Hubbs et al. 1977; Department of Interior 1998). River flow is 
augmented downstream of Presido by waters flowing from the Rio Conchos. 
The near-continuous input of municipal waste has led to a deterioration 
of water quality, with corresponding changes to the ichthyofauna (fish 
species assemblage within a region) (Hubbs et al. 1977; Bestgen and 
Platania 1988; IBWC 1994; El-Hage and Moulton 1998a). Flows in this 
reach consist of a blend of raw river water, treated municipal waste 
from El Paso, TX, untreated municipal water from Juarez, Mexico, 
irrigation return flow, and the occasional floodwater (Texas Water 
Development Board 2001). Water temperature patterns can be elevated and 
oxygen levels decreased by the input of various pollutants (e.g., 
nitrogen, phosphorus) (Texas Water Development Board 2001; IBWC 2001b). 
Water quality is believed to improve farther downstream of the 
confluence of the Rio Conchos and Rio Grande. The development of 
agriculture and population growth in this area has resulted in a 
decrease of water quantity and quality, which has had a significant 
impact on the range and distribution of many fish species within this 
reach (IBWC 1994; El-Hage and Moulton 1998a). There are no current or 
museum records of silvery minnow from this reach (Service 1999). 
Because of upstream dewatering and the degraded water quality, we 
believe this reach of river would never provide suitable habitat for 
the silvery minnow. Thus, this river reach is not essential to the 
conservation of the silvery minnow and is not designated as critical 
habitat.
    6. The upstream boundary of Big Bend National Park 2 mi (3.2 km) 
downstream of Lajitas), Brewster County, to the southern boundary of 
the wild and scenic river designation at Terrell/Val Verde County line, 
TX. This approximately 230-mi (368-km) reach of the lower Rio Grande 
was historically occupied but is currently unoccupied by the silvery 
minnow (Hubbs 1940; Trevino-Robinson 1959; Hubbs et al. 1977; Bestgen 
and Platania 1991). The continuing presence of members of the pelagic 
spawning guild (e.g., speckled chub and Rio Grande shiner) are evidence 
that the lower Rio Grande through Big Bend National Park area may 
support reestablishment of the

[[Page 8124]]

silvery minnow (Platania 1990; IBWC 1994). Moreover, water quality, 
compared to the reach upstream of the Park, is greatly improved in this 
reach by the many freshwater springs within Big Bend National Park 
(MacKay 1993; R. Skiles, pers. comm. 2001; IBWC 1994). This area is 
protected and managed by the National Park Service, and the river 
currently supports a relatively stable hydrologic regime (R. Skiles, 
pers. comm. 2001). The National Park Service's management authority 
over the wild and scenic river designation currently extends 0.25 mi 
(0.4 km) from the ordinary high water mark. Thus, the area designated 
as a wild and scenic river outside of Big Bend National Park is 
currently managed by the National Park Service under its authorities 
and is considered part of the National Park System.
    As discussed above, we have determined that recovery of the silvery 
minnow requires reestablishing populations outside of the middle Rio 
Grande (see ``Recovery Plan'' section above) and should include areas 
within the lower Rio Grande. Because the silvery minnow has been 
extirpated from this reach, Federal agencies have determined that their 
actions will not adversely affect the silvery minnow and therefore have 
not consulted with us under section 7(a)(2) about their actions related 
to this reach. We believe it is important to ensure that the assistance 
of Federal agencies, the State of Texas resource agencies, and non-
Federal entities in future recovery actions, such as the establishment 
of an experimental population, is not compromised. Although Big Bend 
National Park expressed support for a critical habitat designation for 
the silvery minnow within the National Park, it also indicated that if 
areas outside the National Park but within the wild and scenic river 
were included, their attempts at developing a river management plan 
could be compromised (F. Deckert, Big Bend National Park, pers. comm.).
    We have determined that this reach is essential to the conservation 
of the silvery minnow. However, our conservation strategy for the 
silvery minnow is to establish populations within its historic range 
under section 10(j) of the Act, and all or portions of this river reach 
could be included in such an effort. We believe that this area will 
contribute to the recovery of the silvery minnow, but have not 
designated this river reach as critical habitat.
    7. The Terrell/Val Verde County line, TX to the Amistad Dam, TX. 
This short reach is highly influenced by the Amistad Dam at its 
terminus. It is also believed that introduced fish played a role in the 
extirpation of silvery minnow in this reach (Bestgen and Platania 
1991). Water quality conditions within this reach are generally 
degraded, and are also a concern for this reach, particularly during 
low-flow conditions (Texas Water Development Board 2001; Texas Natural 
Resource Conservation Commission 1996). For these reasons, we do not 
believe that this river reach is essential to the conservation of the 
silvery minnow; therefore, it is not designated as critical habitat.
    8. Downstream of the Amistad Dam to the Falcon Dam, Val Verde, 
Kinney, Maverick, Web, Zapata, and Starr Counties, TX. This reach 
provides continuous base flows ranging between 500 and 3000 cfs 
(Service 1999), but the reach is highly urbanized and has many instream 
barriers (e.g., earthen dams) at Maverick, Eagle Pass, and Indio that 
would prevent movements of silvery minnow. Water quality is also a 
potential concern for this reach, particularly during low-flow 
conditions (Texas Water Development Board 2001; Texas Natural Resource 
Conservation Commission 1996). This reach is heavily channelized with 
little to no stream braiding and inappropriate substrate (e.g., cobble) 
in areas. There is no suitable habitat for the silvery minnow within 
this reach, and the species was last recorded here in the 1950s 
(Service 1999). The fish community within this reach is dominated by 
warm water non-native predators (Platania 1990; Service 1999). Because 
this reach does not have suitable habitat for the silvery minnow and 
water quality during variable flow conditions is a concern, this reach 
of river is not essential to the conservation of the silvery minnow and 
is not designated as critical habitat.
    9. Downstream of Falcon Reservoir to the Gulf of Mexico, Starr, 
Hildago, and Cameron, Counties, TX. The silvery minnow historically 
occupied this reach of river (Service 1999). In fact, the type locality 
(the location from which the species was originally described) for the 
species is Brownsville, TX (Hubbs and Ortenburger 1929). However, the 
last collection of the silvery minnow occurred in 1961 just downstream 
of Falcon Reservoir (Bestgen and Platania 1991). The flow regime of 
this reach of the Rio Grande is highly influenced by releases from 
Falcon Reservoir. Most of the tributary inflow is controlled or 
influenced by small impoundments off the main river channel. The lower 
portion of this reach is often dewatered, with the river flow stopping 
before the confluence with the Gulf of Mexico (IBWC 2001b). The fish 
community in this reach of the Rio Grande has shifted significantly 
toward estuarine (a mixture of fresh and salt water) type species (IBWC 
1994; Contreras-B. and Lozano-V.1994). There has also been a 
significant loss of the native fish fauna in the Mexican tributaries in 
the last several decades (Hubbs et al. 1977; Almada-Villela 1990; 
Platania 1990), apparently from poor water quality (e.g., Texas Water 
Development Board 2001; Texas Natural Resource Conservation Commission 
1996). Finally, invasive weeds (e.g., hydrilla and hyacinth) have 
clogged many areas of this reach and have reduced the amount of 
dissolved oxygen in the water (IBWC 2001b). Because this reach does not 
have suitable habitat, there appears to be little benefit in trying to 
intensively manage the flow regime in this reach of river. For these 
reasons, this reach is not considered essential to the conservation of 
the silvery minnow and is not designated as critical habitat.
    10. Pecos River from Santa Rosa Reservoir to Sumner Dam, Guadalupe 
County, NM. This reach is approximately 55 mi (89 km) and is typified 
by wide fluctuations in flow regimes from upstream releases from Santa 
Rosa Reservoir (Hoagstrom 2000). Within this reach there is one 
diversion at Puerto del Luna, NM. The silvery minnow has not been 
collected within this reach since 1939 (Bestgen and Platania 1991; 
Service 1999). The habitat in this reach is not suitable for the 
silvery minnow because much of the surrounding topography is composed 
of steep cliffs and canyons (Hoagstrom 2000). Canyon habitat does not 
provide suitable habitat (e.g., shallow, braided, streams with sandy 
substrates) for the silvery minnow (Bestgen and Platania 1991; Dudley 
and Platania 1997; Remshardt et al. 2001). Because of the short length 
of this reach, fluctuations in the flow regime, and the absence of 
suitable habitat for the silvery minnow, this reach of river is not 
essential to the conservation of the silvery minnow and is not 
designated as critical habitat.
    11. Middle Pecos Reach--approximately 214 mi (345 km) of river 
immediately downstream of Sumner Reservoir to the Brantley Reservoir 
Dam in De Baca, Chaves, and Eddy Counties, NM. The Pecos River was 
historically occupied but is currently unoccupied by the silvery minnow 
(Bestgen and Platania 1991). In fact, the silvery minnow was once one 
of the most common fish species present between Sumner and Avalon 
Reservoir (the area currently inundated by Brantley Reservoir) (Bestgen 
and Platania 1991). The Pecos River can support a relatively

[[Page 8125]]

stable hydrologic regime between Sumner and Brantley Reservoirs, and, 
until summer 2001, this stretch had maintained continuous flow for 
about the last 10 years (D. Coleman, pers. comm. 2001). Groundwater 
seepage areas and base flow supplementation from Sumner Dam bypasses 
can offer a degree of stability for the river flow, especially during 
low flow periods (Hatch et al. 1985; Service 2001). Still, segments of 
this river reach were dewatered for at least 5 days during summer 2001 
(D. Coleman, pers. comm 2001). Although springs and irrigation return 
flows maintain water flow in the lower portions of this river reach 
during times when no water is being released from Sumner Dam, periods 
of low discharge or intermittency have the potential to impact much of 
the suitable habitat within portions of this reach (Service 2001).
    After the construction of Sumner Dam, major channel incision 
(deepening) occurred during the 1949 to 1980 period, accompanied by 
salt cedar (Tamarix ramosissima) proliferation along the river banks 
(Hoagstrom 2000). High-velocity flows within the incised river channel 
can displace eggs from pelagic spawners such as the silvery minnow. 
This channel incision also reduced the areas of low-velocity habitat 
within this river reach (Hoagstrom 2000). Recently, lengthy reservoir 
releases such as those that occurred in 1988 (36 days) and in 1989 (56 
days) have been shortened to about 10 days, which has benefitted 
species such as the Pecos bluntnose shiner (Service 2001). 
Nevertheless, historic block releases of water from Sumner Reservoir 
have modified river flows and habitat (e.g., the downstream river 
reaches have increased in depth and water velocity) (Hoagstrom 2000).
    The recovery of the silvery minnow requires reestablishing 
populations outside of the middle Rio Grande (Service 1999). We believe 
that reintroduction is required outside of the area presently occupied 
by the species (i.e., the middle Rio Grande) to ensure the recovery of 
the silvery minnow (50 CFR 424.12(e)) (see ``Recovery Plan'' section 
above). We recognize that habitat within this river reach is degraded, 
but believe this reach within the middle Pecos River may provide one of 
the most promising areas for conducting recovery efforts because we 
believe it still contains habitat suitable for the silvery minnow 
(Hoagstrom 2000). The continuing presence of members of the pelagic 
spawning guild (e.g., speckled chub, Rio Grande shiner, Pecos bluntnose 
shiner) is evidence that this reach of the Pecos River contains habitat 
suitable for the silvery minnow and may support reestablishment of the 
species (Hoagstrom 2000).
    Federal agencies have not consulted with us on how their actions 
will affect the silvery minnow, because the species no longer occurs 
within the Pecos River (D. Coleman, pers. comm. 2001). Because habitat 
suitable for the silvery minnow is still present within this river 
reach, we find that this river reach is essential to the conservation 
of the species. Although we have determined that this reach is 
essential to the conservation of the silvery minnow, we have not 
designated this area as critical habitat (see ``Exclusions Under 
Section 4(b)(2) of the Act'' section above). Our conservation strategy 
is to develop, through Federal rulemaking procedures, one or more 
experimental populations within the historic range of the silvery 
minnow. We believe this river reach may provide a suitable area for an 
experimental population.
    12. Downstream of Brantley Reservoir, Eddy County, NM to Red Bluff 
Reservoir, Loving and Reeves Counties, TX. This reach is short, with a 
highly variable flow regime that is dependent on agricultural demand. 
This reach is also highly segmented, with small closely placed 
impoundments (e.g., permanent and temporary diversion dams) that pond 
water, impede fish movements, and would not allow for adequate stream 
length (e.g., 134 to 223 mi (216 to 358.8 km)) to ensure the survival 
of downstream drift of eggs and larvae and recruitment of adults 
(Platania and Altenbach 1998). Additionally, agricultural and oil field 
pollution and Permian salts (i.e., brine) are added to the river in 
this reach, decreasing the water quality to levels that likely would 
not support the silvery minnow (Campbell 1959; Larson 1994). The 
silvery minnow was historically uncommon within this reach; only14 
specimens from two collections are known (Bestgen and Platania 1991). 
Due to the short length of this reach, fluctuations in the flow regime, 
degraded water quality, and the absence of suitable habitat for the 
silvery minnow, this reach is not considered essential to the 
conservation of the silvery minnow and is not designated as critical 
habitat.
    13. Downstream of Red Bluff Reservoir to the confluence with the 
Rio Grande, Loving, Reeves, Pecos, Ward, Crane, Crockett, and Terrell 
Counties, TX. Historically silvery minnows occurred in this reach, 
though their exact distribution and abundance is unclear (Campbell 
1958; Trevino-Robinson 1959; James and De La Cruz 1989; Linam and 
Kleinsasser 1996; Garrett 1997; Service 1999). Bestgen and Platania 
(1991) suggest that silvery minnows may have been uncommon within this 
reach because of pond habitat and high water salinity. However, this 
area may not have been well surveyed when the silvery minnow was still 
extant in the Pecos River (D. Propst, New Mexico Game and Fish, pers. 
comm. 2001). Sampling the middle and lower parts of this river reach 
has been historically difficult because of dense vegetation, steep 
canyon banks, and lack of public access (Campbell 1959). The upper 
segment of this reach can be characterized as devoid of suitable 
habitat, and has a highly variable flow regime from release of water 
from Red Bluff Reservoir for agricultural use. Indeed, many freshwater 
springs that historically augmented the Pecos River throughout this 
reach have recently diminished or gone dry (Campbell 1959; Brune 1981 
cited in Hoagstrom 2000; Barker et al. 1994; El-Hage and Moulton 
1998b). The water quality in this upper portion is also poor and 
dominated by high salinity (generally exceeding 5 parts per thousand) 
(Hiss 1970; Hubbs 1990; Linam and Kleinsasser 1996; Miyamoto et al. 
1995; El-Hage and Moulton 1998b). Additionally, algal blooms 
(Prymnesium parvum) have essentially eliminated all the fishes 
throughout from Malaga, NM, to Amistad Dam, TX (James and De la Cruz 
1989; Hubbs 1990; Rhodes and Hubbs 1992). The river channel is also 
somewhat incised and dominated by non-native vegetation in parts 
(Koidin 2000; Harman 1999; IBWC 2001b). Agricultural needs diminish 
south of Girvin, TX, and water quality conditions (e.g., salinity) 
generally begin to improve downstream from the confluence of 
Independence Creek to Amistad Dam (Hubbs 1990; Linam and Kleinsasser 
1996). This improvement could result from the freshwater springs within 
the lower 100 mi (160 km) stretch of this reach. Nevertheless, gaging 
records from the lower segment indicate that there is virtually no flow 
during drought conditions (Texas Water Development Board 2001); 
further, water quality (e.g., total dissolved solids) at Shumla Bend, 
just upstream of Amistad Reservoir, would be expected to have a 
deleterious effect on aquatic life (IBWC 1994).
    We did not include this reach because the current or potential 
suitability for the silvery minnow is unknown; detailed habitat studies 
have not been conducted in this reach. Moreover, it is believed that 
this area contains a network of steep canyons, with rock and coarse 
gravel substrate (Campbell 1959;

[[Page 8126]]

Texas Parks and Wildlife 1999). Canyon habitat reduces river channel 
width, which decreases sinuosity and meandering, and creates deep 
channels that do not provide suitable habitat (e.g., shallow, braided 
streams with sandy substrates) (Bestgen and Platania 1991; Dudley and 
Platania 1997; Remshardt et. al 2001). Additionally, the presence of 
algal blooms will continue to affect water quality in this reach. For 
these reasons, we do not believe that this reach is essential to the 
conservation of the silvery minnow. It is unknown whether this reach 
contains or has the potential to develop the primary constituent 
elements. Although portions of this river reach may contain fresh water 
(i.e., salinity less than 1 part per thousand), we suspect that much of 
this river reach may never provide suitable habitat for the silvery 
minnow, and it is not designated as critical habitat. On June 6, 2002, 
we proposed designating 212 mi of critical habitat for the silvery 
minnow. This final rule designates 157 mi as critical habitat for the 
silvery minnow.

Land Ownership

    Except for the river reaches on Pueblos lands covered by special 
management plans (see ``Relationship of Critical Habitat to Pueblo 
Lands under Section 3(5)(A) and Exclusions Under Section 4(b)(2)'' 
section), the designated critical habitat for the silvery minnow 
encompasses river reaches where the species has been collected in the 
recent past and where it is currently known to exist. Critical habitat 
for the silvery minnow includes both the active river channel and the 
area of bankfull width plus 300 feet on either side of the banks, 
except in areas narrowed by existing levees.
    Ownership of the river channel and the lateral width along the bank 
is unclear in the designated critical habitat of the middle Rio Grande. 
However, most of the land in the middle Rio Grande valley that abuts 
critical habitat is within the administrative boundaries of the MRGCD. 
The MRGCD is a political subdivision of the State of New Mexico that 
provides for irrigation, flood control, and drainage of the middle Rio 
Grande valley in NM, from Cochiti Dam downstream 150 mi (285 km) to the 
northern boundary of the Bosque del Apache National Wildlife Refuge. 
Within these 150 mi are also the lands of the communities of Algodones, 
Bernalillo, Rio Rancho, Corrales, Albuquerque, Los Lunas, Belen, 
Socorro, and a number of smaller incorporated and unincorporated 
communities. Other landowners, sovereign entities, and managers 
include: the Pueblos of Cochiti, Santo Domingo, San Felipe, Santa Ana, 
Sandia, and Isleta; the BOR; the Service; the U.S. Bureau of Land 
Management (BLM); New Mexico State Parks Division; New Mexico 
Department of Game and Fish; New Mexico State Lands Department; and the 
Corps. The Pueblo lands of Santo Domingo, Santa Ana, Sandia, and Isleta 
include 29.5 river mi (47.5 km), and are not included in the final 
designation.

Effect of Critical Habitat Designation

Section 7 Consultation

    Section 7(a)(2) of the Act requires Federal agencies, including 
ourselves, to ensure that actions they fund, authorize, or carry out do 
not destroy or adversely modify critical habitat to the extent that the 
action appreciably diminishes the value of the critical habitat for the 
survival and recovery of the species. Individuals, organizations, 
States, Indian Pueblos and Tribes, local governments, and other non-
Federal entities are affected by the designation of critical habitat 
only if their actions occur on Federal lands, require a Federal permit, 
license, or other authorization, or involve Federal funding.
    Activities on Federal lands that may affect the silvery minnow or 
its critical habitat will require section 7 consultation. Actions on 
private, State, or Indian Pueblo and Tribal lands receiving funding or 
requiring a permit from a Federal agency also will be subject to the 
section 7 consultation process if the action may affect critical 
habitat. Federal actions not affecting the species or its critical 
habitat, as well as actions on non-Federal lands that are not federally 
funded or permitted, will not require section 7 consultation. 
Regulations implementing this interagency cooperation provision of the 
Act are codified at 50 CFR part 402.
    Section 7(a)(4) of the Act requires Federal agencies to confer with 
us on any action that is likely to jeopardize the continued existence 
of a proposed species or to result in destruction or adverse 
modification of proposed critical habitat. Conference reports provide 
conservation recommendations to assist the agency in eliminating 
conflicts that may be caused by the proposed action. The conservation 
recommendations in a conference report are advisory.
    We may issue a formal conference report if requested by a Federal 
agency. Formal conference reports on proposed critical habitat contain 
a biological opinion that is prepared according to 50 CFR 402.14, as if 
critical habitat were designated. We may adopt the formal conference 
report as a biological opinion if the critical habitat is designated 
and if no significant new information or changes in the action alter 
the content of the opinion (see 50 CFR 402.10(d)).
    Regulations at 50 CFR 402.16 also require Federal agencies to 
reinitiate consultation in instances where we have already reviewed an 
action for its effects on a listed species if critical habitat is 
subsequently designated. Consequently, some Federal agencies may 
request reinitiation of consultation or conferencing with us on actions 
for which formal consultation has been completed, if those actions may 
affect designated critical habitat or adversely modify or destroy 
critical habitat.
    When we issue a biological opinion concluding that a project is 
likely to result in jeopardy or the destruction or adverse modification 
of 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 are 
consistent with the scope of the Federal agency's legal authority and 
jurisdiction, that are economically and technologically feasible, and 
that the Director of the Service believes would avoid the likelihood of 
jeopardizing the continued existence of listed species or result in the 
destruction or adverse modification of 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.
    Section 4(b)(8) of the Act requires us to describe in any proposed 
or final regulation that designates critical habitat a description and 
evaluation of those activities involving a Federal action that may 
adversely modify such habitat or that may be affected by such 
designation. When determining whether any of these activities may 
adversely modify critical habitat, we will analyze the effects of the 
action in relation to designated critical habitat (Service and National 
Marine Fisheries Service 1998). Therefore, the analysis (i.e., the 
determination whether an action destroys or adversely modifies critical 
habitat) conducted through consultation or conferencing should evaluate 
whether that loss, when added to the environmental baseline, is likely 
to appreciably diminish the capability of critical habitat to satisfy 
essential

[[Page 8127]]

requirements of the species. In other words, activities that may 
destroy or adversely modify critical habitat include those that alter 
the primary constituent elements (defined above) to an extent that the 
value of critical habitat for the silvery minnow is appreciably reduced 
(50 CFR 402.02).
    A number of Federal agencies or departments fund, authorize, or 
carry out actions that may affect the silvery minnow and its designated 
critical habitat. We have reviewed and continue to review numerous 
activities proposed within the range of the silvery minnow that are 
currently the subject of formal or informal section 7 consultations. A 
wide range of Federal activities have the potential to destroy or 
adversely modify critical habitat of the silvery minnow. These 
activities may include land and water management actions of Federal 
agencies (e.g., Corps, BOR, Service, and the Bureau of Indian Affairs) 
and related or similar actions of other federally regulated projects 
(e.g., road and bridge construction activities by the Federal Highway 
Administration; dredge and fill projects, sand and gravel mining, and 
bank stabilization activities conducted or authorized by the Corps; 
construction, maintenance, and operation of diversion structures; 
management of the conveyance channel; levee and dike construction and 
maintenance by the BOR; and NPDES permits authorized by the EPA). These 
types of activities have already been examined under consultation with 
us upon listing the species as endangered and in our previous 
designation of critical habitat. We expect that the same types of 
activities will be reviewed in section 7 consultation now that critical 
habitat is again designated. However, there is some potential for an 
increase in the number of proposed actions we review under section 7 of 
the Act from actions proposed in areas that are contained within the 
300-foot lateral width. We believe that we currently review most 
actions (e.g., indirect effects) that could affect silvery minnow 
through section 7 that occur in this lateral width, but acknowledge 
that an explicit boundary could result in a slight increase in 
consultations.
    Activities that we are likely to review under section 7 of the Act 
include, but are not limited to:
    1. Significantly and detrimentally altering the river flow or the 
natural flow regime of any of the river reaches designated in the 
middle Rio Grande. Possible actions would include groundwater pumping, 
impoundment, and water diversion with a Federal nexus (i.e., activities 
that are authorized, funded, or carried out by a Federal agency). We 
note that such flow reductions that result from actions affecting 
tributaries of the designated river reaches may also destroy or 
adversely modify critical habitat.
    2. Significantly and detrimentally altering the characteristics of 
the 300-ft (91.4-m) lateral width (e.g., parts of the floodplain) in 
the designated critical habitat of the middle Rio Grande. Possible 
actions would include vegetation manipulation, timber harvest, road 
construction and maintenance, prescribed fire, livestock grazing, off-
road vehicle use, powerline or pipeline construction and repair, 
mining, and urban and suburban development with a Federal nexus.
    3. Significantly and detrimentally altering the channel morphology 
(e.g., depth, velocity) of any of the river reaches within the 
designation. Possible actions would include channelization, 
impoundment, road and bridge construction, deprivation of substrate 
source, reduction of available floodplain, removal of gravel or 
floodplain terrace materials, reduction in stream flow, and excessive 
sedimentation from mining, livestock grazing, road construction, timber 
harvest, off-road vehicle use, and other watershed and floodplain 
disturbances with a Federal nexus.
    4. Significantly and detrimentally altering the water quality 
within the designation. Possible actions with a Federal nexus would 
include EPA's NPDES permitting or the release of chemical or biological 
pollutants into the surface water or connected groundwater at a point 
source or by dispersed release (non-point).
    5. Introducing, spreading, or augmenting non-native aquatic species 
within the designation. Possible actions with a Federal nexus would 
include fish stocking for sport, aesthetics, biological control, or 
other purposes; use of live bait fish; aquaculture; construction and 
operation of canals; and interbasin water transfers.
    Not all of the identified activities are necessarily of current 
concern within the middle Rio Grande. However, they do indicate the 
potential types of activities that will require consultation and, 
therefore, may be affected by the designation of critical habitat. We 
do not expect that the designation of critical habitat will result in a 
significant regulatory burden above that already in place because of 
the presence of the listed species. However, areas included within the 
300-ft (91.4-m) lateral width of the designation that are not currently 
occupied by the species may result in an additional regulatory burden 
when there is a Federal nexus (Federal funding, authorization, or 
permit).
    As discussed previously, Federal actions that are found likely to 
destroy or adversely modify critical habitat may often be modified, 
through development of reasonable and prudent alternatives, in ways 
that will remove the likelihood of destruction or adverse modification 
of critical habitat. Such project modifications may include such things 
as adjustment in timing of projects to avoid sensitive periods for the 
species and its habitat; replanting of riparian vegetation; 
minimization of work and vehicle use in the main river channel or the 
300-ft (91.4-m) lateral width; restriction of riparian and upland 
vegetation clearing in the 300-ft (91.4-m) lateral width; fencing to 
exclude livestock and limit recreational use; use of alternative 
livestock management techniques; avoidance of pollution; minimization 
of ground disturbance in the 300-foot lateral width; use of alternative 
material sources; storage of equipment and staging of operations 
outside the 300-foot lateral width; use of sediment barriers; access 
restrictions; and use of best management practices to minimize erosion.
    The silvery minnow does not need a large quantity of water to 
survive but it does need a sufficient amount of flowing water to reduce 
prolonged periods of low or no flow and minimize the formation of 
isolated pools. The identification of primary constituent elements for 
the silvery minnow is not intended to create a high-velocity, deep 
flowing river, with a bank-to-bank flow. The silvery minnow does not 
require such habitat characteristics. Instead, the silvery minnow 
requires habitat with sufficient flows through the irrigation season to 
avoid prolonged periods of low or no flow; additionally, a spike in 
flow in the late spring or early summer to trigger spawning, and a 
relatively constant winter flow are also required.
    If you have questions regarding whether specific activities will 
likely constitute destruction or adverse modification of critical 
habitat, contact the Field Supervisor, New Mexico Ecological Services 
Field Office (see ADDRESSES and FOR FURTHER INFORMATION CONTACT 
sections). If you would like copies of the regulations on listed 
wildlife or have questions about prohibitions and permits, contact the 
U.S. Fish and Wildlife Service, Division of Endangered Species (see 
ADDRESSES and FOR FURTHER INFORMATION CONTACT sections).

Economic Analysis

    Section 4(b)(2) of the Act requires that we designate critical 
habitat on the basis

[[Page 8128]]

of the best scientific and commercial information available and that we 
consider the economic and other relevant impacts of designating a 
particular area as critical habitat. We based this final rule on the 
best available scientific information, including the recommendations in 
the Recovery Plan (Service 1999). In order to make a final critical 
habitat designation, we furthered utilized the economic analysis and 
our analysis of other relevant impacts, and considered all comments and 
information submitted during the public hearing and comment period. No 
areas proposed as critical habitat were excluded or modified because of 
economic impacts. However, we have excluded areas from the final 
designation on the basis of a final determination that the benefits of 
such exclusions outweigh the benefits of specifying such areas as 
critical habitat (see ``Exclusions Under Section 4(b)(2) of the Act'' 
section). In accordance with section 4(b)(2) of the Act, we cannot 
exclude areas from critical habitat when their exclusion will result in 
the extinction of the species. We have prepared an economic analysis 
that was available for public review and comment during the comment 
period for the proposed rule. You can request copies of the economic 
analysis and EIS from the New Mexico Ecological Services Field Office 
(see ADDRESSES section).
    Section 4(b)(2) of the Act and 50 CFR 424.19 require us to consider 
the economic impact, and any other relevant impact, of specifying any 
particular area as critical habitat. Executive Order 12866 defines 
``significant regulatory action,'' in part, as a regulatory action that 
is likely to result in a rule that may have an annual effect on the 
economy of $100 million or more. The final Economic Analysis for this 
rule estimates that the potential economic effects could range from 
$1.9 to $16.2 million annually. This includes potential economic 
effects related to consultations, project modifications, and providing 
target flows, including those effects that may be attributed co-
extensively with the listing of the species. Thus, we do not believe 
that the adverse modification prohibition (from critical habitat 
designation) will have significant economic effects such that it will 
have an annual economic effect of $100 million or more. We recognize, 
however, that while the impacts may not be considered ``significant'' 
under Executive Order 12866, there will be some economic impact within 
the middle Rio Grande area. Additionally, the final Economic Analysis 
recognizes the benefits associated with conservation of an endangered 
species. The economic analysis provides information on the social 
welfare benefits associated with maintaining instream flows in the 
Middle Rio Grande (e.g., ecological improvements, recreational 
opportunities, and protection afforded to other species). These 
benefits are described in detail in the final Economic Analysis. On the 
basis of our evaluation of lands proposed as critical habitat, we 
believe that the designation of the lands in this final rule as 
critical habitat are essential to the conservation of the silvery 
minnow, and these lands are currently occupied by the species. 
Consequently, none of the proposed lands have been excluded from the 
designation on the basis of potential economic impacts pursuant to 
section 4(b)(2) of the Act.

American Indian Tribal Rights, Federal-Tribal Trust Responsibilities, 
and the Endangered Species Act

    In accordance with Secretarial Order 3206, ``American Indian Tribal 
Rights, Federal-Tribal Trust Responsibilities, and the Endangered 
Species Act'' (June 5, 1997); the President's memorandum of April 29, 
1994, ``Government-to-Government Relations with Native American Tribal 
Governments'' (May 9, 1994, 59 FR 22951); Executive Order 13175; and 
the Department of the Interior's requirement at 512 DM 2, we believe 
that, to the maximum extent possible, Indian Pueblos and Tribes should 
be the governmental entities to manage their lands and tribal trust 
resources. To this end, we support tribal measures that preclude the 
need for Federal conservation regulations. We provided technical 
assistance to Indian Pueblos and Tribes who asked for assistance in 
developing and expanding tribal programs for the management of healthy 
ecosystems so that Federal conservation regulations, such as 
designation of critical habitat, on tribal lands are unnecessary.
    The Presidential Memorandum of April 29, 1994, also requires us to 
consult with the Indian Pueblos and Tribes on matters that affect them, 
and section 4(b)(2) of the Act requires us to gather information 
regarding the designation of critical habitat and the effects thereof 
from all relevant sources, including Indian Pueblos and Tribes. 
Recognizing a government-to-government relationship with Indian Pueblos 
and Tribes and our Federal trust responsibility, we have and will 
continue to consult with the Indian Pueblos and Tribes that might be 
affected by the designation of critical habitat.
    We consulted with the affected Indian Pueblos and Tribes during the 
comment period for the proposed rule to gain information on: (1) 
Possible effects if critical habitat were designated on Tribal lands; 
and (2) possible effects on tribal resources resulting from the 
proposed designation of critical habitat on non-tribal lands. At their 
request, we met with each potentially affected Pueblo or Tribe to 
ensure that government-to-government consultation on proposed critical 
habitat issues occurred in a timely manner.

Designation of Critical Habitat on Tribal Lands

    Section 3(5) of the Act defines critical habitat, in part, as areas 
within the geographical area occupied by the species ``on which are 
found those physical and biological features (I) essential to the 
conservation of the species and (II) which may require special 
management considerations and protection.'' We included lands of the 
Indian Pueblos of Cochiti, Santo Domingo, San Felipe, Santa Ana, 
Sandia, and Isleta in the proposed designation of critical habitat for 
the silvery minnow; however, Santo Domingo, Santa Ana, Sandia, and 
Isleta were not included for the final designation because they 
submitted sufficient management plans during the open comment period, 
and we concluded that these river reaches did not meet the definition 
of critical habitat because adequate special management is being 
provided for the silvery minnow on these lands. The plans and our 
analysis of other relevant issues are summarized above under the 
``Relationship of Critical Habitat to Pueblo Lands Under Section 
3(5)(A) and Exclusions Under Section 4(b)(2)'' section.

Effects on Tribal Trust Resources From Critical Habitat Designation on 
Non-Tribal Lands

    We do not anticipate that the proposal of critical habitat on non-
tribal lands will result in any impact on tribal trust resources or the 
exercise of tribal rights. However, in complying with our tribal trust 
responsibilities, we communicated with all Indian Pueblos and Tribes 
potentially affected by the designation. At their request, we arranged 
meetings with them during the comment period on potential effects to 
them or their resources that may result from critical habitat 
designation. We sent preproposal letters and the proposed rule and 
associated documents to all affected Indian Pueblos, including Cochiti, 
Santo Domingo, San Felipe, Santa Ana, Sandia, Isleta, and San Juan,

[[Page 8129]]

and solicited additional information from them regarding biological, 
cultural, social, or economic data pertinent to the proposed rule, 
economic analysis, or EIS. We will continue to provide assistance to 
and cooperate with Indian Pueblos and Tribes that potentially could be 
affected by this critical habitat designation at their request.

Required Determinations

Regulatory Planning and Review

    In accordance with Executive Order 12866, this document is a 
significant rule as the Office of Management and Budget (OMB) 
determined that this rule may raise novel legal or policy issues, but 
was not reviewed by OMB due to the court ordered deadline. We prepared 
an economic analysis of this action. We used this analysis to meet the 
requirement of section 4(b)(2) of the Endangered Species Act to 
determine the economic consequences of designating the specific areas 
as critical habitat. The draft economic analysis was made available for 
public comment, and we considered those comments during the preparation 
of this rule. The draft analysis indicates that this rule will not have 
an annual economic effect of $100 million or more or adversely affect 
an economic sector, productivity, jobs, the environment, or other units 
of government. Under the Act, critical habitat may not be destroyed or 
adversely modified by a Federal agency action; the Act does not impose 
any restrictions related to critical habitat on non-Federal persons 
unless they are conducting activities funded or otherwise sponsored or 
permitted by a Federal agency. Because of the potential for impacts on 
other Federal agencies' activities, we reviewed this action for any 
inconsistencies with other Federal agency actions. We believe that this 
rule will not materially affect entitlements, grants, user fees, loan 
programs, or the rights and obligations of their recipients, except 
those involving Federal agencies which would be required to ensure that 
their activities do not destroy or adversely modify designated critical 
habitat. As discussed above, we do not anticipate that the adverse 
modification prohibition (from critical habitat designation) will have 
any significant economic effects such that it will have an annual 
economic effect of $100 million or more. OMB has determined that the 
critical habitat portion of this rule will raise novel legal or policy 
issues, but this rule was not reviewed by OMB due to the court ordered 
deadline. The final rule follows the requirements for designating 
critical habitat contained in the Act.

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

    Under the Regulatory Flexibility Act (as amended by the Small 
Business Regulatory Enforcement Fairness Act (SBREFA) of 1996; 5 U.S.C. 
804(2)), whenever a Federal 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 effect of the rule on small entities (i.e., small 
businesses, small organizations, and small government jurisdictions). 
However, no regulatory flexibility analysis is required if the head of 
an agency certifies that the rule will not have a significant economic 
impact on a substantial number of small entities. SBREFA amended the 
Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a rule will not have 
a significant economic impact on a substantial number of small 
entities. We are certifying that the rule will not have a significant 
effect on a substantial number of small entities. The following 
discussion explains our rationale.
    The economic analysis determined whether this critical habitat 
designation potentially affects a ``substantial number'' of small 
entities in counties supporting critical habitat areas. It also 
quantifies the probable number of small businesses that experience a 
``significant effect.'' While SBREFA does not explicitly define either 
``substantial number'' or ``significant effect,'' the Small Business 
Administration (SBA) and other Federal agencies have interpreted these 
terms to represent an impact on 20 percent or more of the small 
entities in any industry and an effect equal to 3 percent or more of a 
business' annual sales.
    Based on the past consultation history for the silvery minnow, 
wastewater discharges from municipal treatment plants are the primary 
small business activities anticipated to be affected by the designation 
of critical habitat. To be conservative, (i.e., more likely to 
overstate impacts than understate them), the economic analysis assumes 
that a unique company will undertake each of the projected 
consultations in a given year, and so the number of businesses affected 
is equal to the total annual number of consultations (both formal and 
informal).
    The first step was to estimate the number of small businesses 
affected. As shown in Exhibit 1 below, the following calculations yield 
this estimate:
    [sbull] Estimate the number of businesses within the study area 
affected by section 7 implementation annually (assumed to be equal to 
the number of annual consultations);
    [sbull] Calculate the percent of businesses in the affected 
industry that are likely to be small;
    [sbull] Calculate the number of affected small businesses in the 
affected industry;
    [sbull] Calculate the percent of small businesses likely to be 
affected by critical habitat.

   Exhibit 1.--Estimated Annual Number of Small Businesses Affected by
         Critical Habitat Designation: The ``Substantial'' Test
------------------------------------------------------------------------
                                                             Sanitary
                      Industry name                        services  ISC
                                                              \1\4959
------------------------------------------------------------------------
Annual number of affected businesses in industry:
    By formal consultation..............................            0.13
(Equal to number of annual consultations): \2\
    By informal consultation............................            0.75
Total number of all businesses in industry within study                6
 area
Number of small businesses in industry within study area               6
Percent of businesses that are small (Number of small               100%
 businesses)/(Total Number of businesses)
Annual number of small businesses affected (Number of               0.88
 affected businesses)*(Percent of small businesses)
Annual percentage of small businesses affected (Number              15%
 of small businesses affected)/(Total number of small
 businesses); 20 percent is substantial
------------------------------------------------------------------------
\1\ ISC = Interstate Stream Commission.

[[Page 8130]]

 
\2\ Note that because these values represent the probability that small
  businesses will be affected during a 1-year time period, calculations
  may result in fractions of businesses. This is an acceptable result,
  as these values represent the probability that small businesses will
  be affected.

    This calculation reflects conservative assumptions and nonetheless 
yields an estimate that is still far less than the 20 percent threshold 
that would be considered ``substantial.'' As a result, this analysis 
concludes that a significant economic impact on a substantial number of 
small entities will not result from the designation of critical habitat 
for the silvery minnow. Nevertheless, an estimate of the number of 
small businesses that will experience effects at a significant level is 
provided below.
    Costs of critical habitat designation to small businesses consist 
primarily of the cost of participating in section 7 consultations and 
the cost of project modifications. To calculate the likelihood that a 
small business will experience a significant effect from critical 
habitat designation for the silvery minnow, the following calculations 
were made:
    [sbull] Calculate the per-business cost. This consists of the unit 
cost to a third party of participating in a section 7 consultation 
(formal or informal) and the unit cost of associated project 
modifications. To be conservative, the economic analysis uses the high-
end estimate for each cost.
    [sbull] Determine the amount of annual sales that a company would 
need to have for this per-business cost to constitute a ``significant 
effect.'' This is calculated by dividing the per-business cost by the 3 
percent ``significance'' threshold value.
    [sbull] Estimate the likelihood that small businesses in the study 
area will have annual sales equal to or less than the threshold amount 
calculated above. This is estimated using national statistics on the 
distribution of sales within industries.
    [sbull] Based on the probability that a single business may 
experience significant effects, calculate the expected value of the 
number of businesses likely to experience a significant effect.
    [sbull] Calculate the percent of businesses in the study area 
within the affected industry that are likely to be affected 
significantly.
    Calculations for costs associated with designating critical habitat 
for the silvery minnow are provided in Exhibit 2 below.

      Exhibit 2.--Estimated Annual Effects on Small Businesses: The
                       ``Significant Effect'' Test
------------------------------------------------------------------------
                                        Sanitary Services  ISC \1\ 4959
                                     -----------------------------------
                                           Formal
              Industry                  consultations       Informal
                                        with project      consultations
                                        modifications
------------------------------------------------------------------------
Annual Number of Small Businesses                 0.13              0.75
 Affected (from final Economic
 Analysis)..........................
Per-Business Cost...................           $34,100            $2,900
Level of Annual Sales Below which           $1,136,667           $96,667
 Effects Would Be Significant (Per-
 Business Cost/3%)..................
Probability that Per-Business Cost                 48%                3%
 is Greater than 3% of Sales for
 Small Business \2\.................
Probable Annual Number of Small                   0.06              0.02
 Businesses Experiencing Significant
 Effects (Number Small Businesses)*
 (Probability of Significant Effect)
                                     -------------------
    Total Annual Number of Small
     Businesses Bearing Significant
     Costs in Industry..............                  0.08
                                     ===================
    Total Annual Percentage of Small
     Businesses Bearing Significant
     Costs in Industry..............                 1.4%
------------------------------------------------------------------------
\1\ ISC = Interstate Stream Commission.
\2\ This probability is calculated based on national industry statistics
  obtained from the Robert Morris Associated Annual Statement of
  Studies: 2001-2002, which provides data on the distribution of annual
  sales in an industry within the following ranges: $0-1 million, $1-3
  million, $3-5 million, $5-10 million, $10-25 million, and $25+
  million. This analysis uses the ranges that fall within the SBA
  definition of small businesses (i.e., for industries in which small
  businesses have sales of less than $5.0 million, it uses $0-1 million,
  $1-3 million, and $3-5 million) to estimate a distribution of sales
  for small businesses. It then calculates the probability that small
  businesses have sales below the threshold value, using the following
  components: (1) All small businesses (expressed as a percentage of all
  small businesses) in ranges whose upper limits fall below the
  threshold value experience the costs as significant; (2) for the range
  in which the threshold value falls, the percentage of companies in the
  bin that fall below the threshold value is calculated as [(threshold
  value--range minimum)/(bin maximum--range minimum)] x percent of small
  businesses captured in range. This percentage is added to the
  percentage of small businesses captured in each of the lower ranges to
  reach the total probability that small businesses have sales below the
  threshold value. Note that in instances in which the threshold value
  exceeds the definition of small businesses (i.e., the threshold value
  is $10 million and the definition of small businesses is sales less
  than $5.0 million), all small businesses experience the effects as
  significant.

    Because the costs associated with designating critical habitat for 
the silvery minnow are likely to be significant for less than one small 
businesses per year (approximately 1 percent of the small businesses in 
the sanitary services industry) in the affected counties, the economic 
analysis concludes that a significant economic impact on a substantial 
number of small entities will not result from the designation of 
critical habitat for the silvery minnow. This would be true even if all 
of the effects of section 7 consultation on these activities were 
attributed solely to the critical habitat designation.

Executive Order 13211

    On May 18, 2001, the President issued an Executive Order (E.O. 
13211) 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. 
We have a very good consultation history for the silvery minnow; thus, 
we can describe the kinds of actions that have undergone consultations. 
Within the critical habitat designated in the middle Rio Grande, the 
BLM has the highest likelihood of any Federal agency to undergo section 
7 consultation for actions relating to energy supply, distribution, or 
use. However, since 1994, the BLM has not conducted any consultations 
for resource management plans that relate to energy supply, 
distribution, or use. We do not anticipate the development of oil and 
gas leases within the area we are designating as critical habitat (J. 
Smith,

[[Page 8131]]

pers. comm. 2001). Nevertheless, if we were to consult on a proposed 
BLM energy-related action, the outcome of that consultation likely 
would not differ from the BLM's policy of not allowing oil and gas 
development within the 100-year floodplain. For these reasons, we do 
not anticipate that this rule will be a significant regulatory action 
under Executive Order 12866, and 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.

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

    In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501 
et seq.):
    1. On the basis of information contained in the Economic Analysis, 
this rule will not ``significantly or uniquely'' affect small 
governments. A Small Government Agency Plan is not required. Small 
governments will be affected only to the extent that any of their 
actions involving Federal funding or authorization must not destroy or 
adversely modify the critical habitat or take the species under section 
9.
    2. This rule will not produce a Federal mandate of $100 million or 
greater in any year (i.e., it is not a ``significant regulatory 
action'' under the Unfunded Mandates Reform Act).

Takings

    In accordance with Executive Order 12630 (``Government Actions and 
Interference with Constitutionally Protected Private Property Rights,'' 
March 18, 1988; 53 FR 8859), we have analyzed the potential takings 
implications of the designation of critical habitat for the silvery 
minnow. The takings implications assessment concludes that this final 
rule does not pose significant takings implications. A copy of this 
assessment can be obtained by contacting the New Mexico Ecological 
Services Field Office (see ADDRESSES section).
    On the basis of the above assessment, we find that this final rule 
designating critical habitat for the silvery minnow does not pose 
significant takings implications.

Federalism

    In accordance with Executive Order 13132, we have considered 
whether this rule has significant Federalism effects and have 
determined that a Federalism assessment is not required. In keeping 
with Department of the Interior policy, we requested information from 
and coordinated development of this final rule with appropriate 
resource agencies in NM and TX (i.e., during the EIS scoping period and 
proposed rule comment period). We will continue to coordinate with the 
appropriate agencies.
    We do not anticipate that this regulation will intrude on State 
policy or administration, change the role of the Federal or State 
government, or affect fiscal capacity. We have conducted two formal 
section 7 consultations with the Corps and BOR, and a non-Federal 
agency (MRGCD) over actions related to water operations on the middle 
Rio Grande (Service 2001b, 2002a). As a result, we do not believe that 
this designation of critical habitat will have significant Federalism 
effects. For example, in the recent formal section 7 consultations, the 
MRGCD's regulatory burden requirement was only affected to the extent 
that the MRGCD was acting as the United States' agent for the operation 
and maintenance of facilities. Federal agencies also must ensure, 
through section 7 consultation with us, that their activities do not 
destroy or adversely modify designated critical habitat. Nevertheless, 
we do not anticipate that the amount of supplemental instream flow, 
provided by past consultations (e.g., Service 2001b), will increase 
because an area is designated as critical habitat. This rule also will 
not change the appropriation of water rights within the area designated 
as critical habitat. For these reasons, we do not anticipate that the 
designation of critical habitat will change State policy or 
administration, change the role of the Federal or State government, or 
affect fiscal capacity.
    Within the 300-ft (91.4-m) lateral width, designation of critical 
habitat could trigger additional review of Federal activities under 
section 7 of the Act, and may result in additional requirements on 
Federal activities to avoid destroying or adversely modifying critical 
habitat. Any action that lacked Federal involvement would not be 
affected by the critical habitat designation. Should a Federally 
funded, permitted, or implemented project be proposed that may affect 
designated critical habitat, we will work with the Federal action 
agency and any applicant, through section 7 consultation, to identify 
ways to implement the proposed project while minimizing or avoiding any 
adverse effect to the species or critical habitat. In our experience, 
the vast majority of such projects can be successfully implemented 
with, at most, minor changes that avoid significant economic impacts to 
project proponents.
    The designation may have some benefit to these governments--the 
areas essential to the conservation of the species would be clearly 
defined, and the primary constituent elements of the habitat necessary 
to the survival of the species would be identified. While 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 (where otherwise they would wait for case-by-
case section 7 consultations to occur).

Civil Justice Reform

    In accordance with Executive Order 12988 (February 7, 1996; 61 FR 
4729), the Office of the Solicitor has determined that this rule would 
not unduly burden the judicial system and would meet the requirements 
of sections 3(a) and 3(b)(2) of the Order. We designate critical 
habitat in accordance with the provisions of the Act. The rule uses 
standard property descriptions and identifies the primary constituent 
elements within the designated areas to assist the public in 
understanding the habitat needs of the silvery 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 the Office of Management and Budget (OMB) under 44 
U.S.C. 3501 et seq. This rule will not impose new 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 Endangered Species Act of 
1973, as amended. 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 Ninth Circuit Douglas County 
v. Babbitt, 48 F.3d 1495 (9th Cir. 1995), cert. denied, 116 S. Ct. 698 
(1996). However, when the range of the species includes States within 
the Tenth Circuit, such as that of the silvery minnow, pursuant to the 
Tenth Circuit ruling in Catron County Board of Commissioners v. U.S. 
Fish and Wildlife Service, 75 F.3d 1429 (10th Cir. 1996), we will 
undertake a NEPA

[[Page 8132]]

analysis for critical habitat designation. Additionally, on November 
21, 2000, the United States District Court for the District of New 
Mexico, in Middle Rio Grande Conservancy District v. Babbitt, 206 F. 
Supp. 2d 1156 (D.N.M. 2000), set aside the July 9, 1999, critical 
habitat designation and ordered us to issue within 120 days both an EIS 
and a new proposed rule designating critical habitat for the silvery 
minnow. We have prepared this designation and the EIS pursuant to that 
court order.

Government-to-Government Relationship With Indian Pueblos and Tribes

    In accordance with the Secretarial Order 3206, ``American Indian 
Tribal Rights, Federal-Tribal Trust Responsibilities, and the 
Endangered Species Act'' (June 5, 1997); 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 the Interior's requirement at 512 DM 2, we understand 
that we must conduct relations to recognized Federal Indian Pueblos and 
Tribes on a Government-to-Government basis. Therefore, we solicited 
information from the Indian Pueblos and Tribes and arranged meetings 
with those that requested during the comment period to discuss 
potential effects to them or their resources that may result from 
critical habitat designation.

References Cited

    A complete list of all references cited in this final rule is 
available upon request from the New Mexico Ecological Services Field 
Office (see ADDRESSES section).

Authors

    The primary authors of this notice are the New Mexico Field Office 
staff (see ADDRESSES section).

List of Subjects in 50 CFR Part 17

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

Regulation Promulgation

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

PART 17--[AMENDED]

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

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


    2. Amend Sec.  17.95(e) by revising critical habitat for the Rio 
Grande silvery minnow (Hybognathus amarus), to read as follows.


Sec.  17.95  Critical habitat--fish and wildlife.

* * * * *
    (e) Fishes. * * *

Rio Grande Silvery Minnow (Hybognathus amarus)

    (1) Designated critical habitat is depicted for Socorro, Valencia, 
Bernalillo, and Sandoval Counties, New Mexico, on the map and as 
described below.
    (2) For each river reach, the upstream and downstream boundaries 
are described below. Critical habitat includes the stream channels 
within the identified river reaches and areas within these reaches 
included within the existing levees, or if no levees are present, then 
within a lateral distance of 300 ft (91.4 m) on each side of the river 
width at bankfull stage. Bankfull stage is the flow at which water 
begins to leave the channel and move into the floodplain. The bankfull 
stage is not defined by water, and can be determined by visual or 
physical indicators, including: The top of the highest depositional 
features (e.g., point bars), staining of rocks, exposed root hairs, and 
other features.
    (3) Within these areas the primary constituent elements include, 
but are not limited to, those habitat components that are essential for 
the primary biological needs of foraging, sheltering, and reproduction. 
These elements include the following:
    (i) A hydrologic regime that provides sufficient flowing water with 
low to moderate currents capable of forming and maintaining a diversity 
of aquatic habitats, such as, but not limited to the following: 
Backwaters (a body of water connected to the main channel, but with no 
appreciable flow), shallow side channels, pools (that portion of the 
river that is deep with relatively little velocity compared to the rest 
of the channel), eddies (a pool with water moving opposite to that in 
the river channel), and runs (flowing water in the river channel 
without obstructions) of varying depth and velocity--all of which are 
necessary for each of the particular silvery minnow life-history stages 
in appropriate seasons (e.g., the silvery minnow requires habitat with 
sufficient flows from early spring (March) to early summer (June) to 
trigger spawning, flows in the summer (June) and fall (October) that do 
not increase prolonged periods of low or no flow, and a relatively 
constant winter flow (November through February));
    (ii) The presence of eddies created by debris piles, pools, or 
backwaters, or other refuge habitat (e.g., connected oxbows or braided 
channels) within unimpounded stretches of flowing water of sufficient 
length (i.e., river miles) that provide a variation of habitats with a 
wide range of depth and velocities;
    (iii) Substrates of predominantly sand or silt; and
    (iv) Water of sufficient quality to maintain natural, daily, and 
seasonally variable water temperatures in the approximate range of 
greater than 1 [deg]C (35 [deg]F) and less than 30 [deg]C (85 [deg]F) 
and reduce degraded conditions (e.g., decreased dissolved oxygen, 
increased pH).
    (4) The Pueblo lands of Santo Domingo, Santa Ana, Sandia, and 
Isleta are not designated.
    (5) Designated critical habitat is depicted on the following map 
for the middle Rio Grande, which includes the area from Cochiti 
Reservoir downstream to the utility line crossing the Rio Grande just 
east of the Bosque Well as demarcated on USGS Paraje Well 7.5 minute 
quadrangle (1980), with the Universal Transverse Mercator (UTM) 
coordinates of UTM Zone 13: 311474 E, 3719722 N (as referenced with the 
1927 North American Datum (NAD27)), Sandoval, Bernalillo, Valencia, and 
Socorro Counties, New Mexico. The designation also includes the upper 
section of the tributary Jemez River from Jemez Canyon Dam to the 
upstream boundary of Santa Ana Pueblo, Sandoval County. The river 
reaches in the middle Rio Grande include:
    (i) Jemez Canyon Reach--1 mi (1.6 km) of the Jemez River 
immediately downstream of Jemez Canyon Dam to the upstream boundary 
Santa Ana Pueblo;
    (ii) Cochiti Diversion Dam to Angostura Diversion Dam (Cochiti 
Reach)--21 mi (34 km) of river immediately downstream of Cochiti 
Reservoir to the Angostura Diversion Dam;
    (iii) Angostura Diversion Dam to Isleta Diversion Dam (Angostura 
Reach)--38 mi (61 km) of river immediately downstream of the Angostura 
Diversion Dam to the Isleta Diversion Dam;
    (iv) Isleta Diversion Dam to San Acacia Diversion Dam (Isleta 
Reach)--56 mi (90 km) of river immediately downstream of the Isleta 
Diversion Dam to the San Acacia Diversion Dam; and
    (v) San Acacia Diversion Dam to the Elephant Butte Dam (San Acacia 
Reach)--92 mi (147 km) of river immediately downstream of the San

[[Page 8133]]

Acacia Diversion Dam to the utility line crossing the Rio Grande just 
east of the Bosque Well demarcated on USGS Paraje Well 7.5 minute 
quadrangle (1980) with UTM coordinates of UTM Zone 13: 311474 E, 
3719722 N.
    (vi) Map Follows:
BILLING CODE 4310-55-P

[[Page 8134]]

[GRAPHIC] [TIFF OMITTED] TR19FE03.000

BILLING CODE 4310-55-C

[[Page 8135]]

    (6) This designation does not include the ephemeral or perennial 
irrigation canals and ditches outside of natural stream channels, 
including the low flow conveyance channel that is adjacent to a portion 
of the river reach within the middle Rio Grande (i.e., downstream of 
the southern boundary of Bosque del Apache National Wildlife Refuge to 
the Elephant Butte Dam).
    (7) Lands located within the exterior boundaries of the critical 
habitat designation (i.e., within the existing levees, or if no levees 
are present, then within a lateral distance of 300 ft (91.4 m) on each 
side of the stream width at bankfull discharge) that are not considered 
critical habitat and are therefore excluded by definition, include: 
Developed flood control facilities; existing paved roads; bridges; 
parking lots; dikes; levees; diversion structures; railroad tracks; 
railroad trestles; water diversion and irrigation canals outside of 
natural stream channels; the low flow conveyance channel; active gravel 
pits; cultivated agricultural land; and residential, commercial, and 
industrial developments.
* * * * *

    Dated: January 31, 2003.
Craig Manson,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 03-3255 Filed 2-18-03; 8:45 am]
BILLING CODE 4310-55-P