[Federal Register Volume 63, Number 116 (Wednesday, June 17, 1998)]
[Rules and Regulations]
[Pages 32981-32996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16099]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17


Endangered and Threatened Wildlife and Plants; Notice of 
Determination To Retain Endangered Status for the Bruneau Hot 
Springsnail in Southwestern Idaho Under the Endangered Species Act

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of determination.

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SUMMARY: The U.S. Fish and Wildlife Service, in a court-ordered 
reconsideration of the 1993 final listing decision, affirms its earlier 
determination that listing the Bruneau Hot Springsnail (Pyrgulopsis 
bruneauensis) as endangered is appropriate. Federal protection pursuant 
to the Endangered Species Act of 1973 (Act), as amended, for the 
Bruneau Hot Springsnail is thus continued. This species occurs only in 
a complex of flowing thermal springs arising from a single source 
aquifer along the Bruneau River in Owyhee County, Idaho. Bruneau Hot 
Springsnails are not known to occur elsewhere and have not been located 
outside of the thermal plumes of hot springs entering the Bruneau 
River. The primary threat to this species is the reduction of thermal 
spring habitats from agricultural-related ground water withdrawal/
pumping.

DATES: The effective date of this notice is June 17, 1998.


[[Page 32982]]


ADDRESSES: The complete file for this notice is available for 
inspection, by appointment, during normal business hours at the Snake 
River Basin Office, U.S. Fish and Wildlife Service, 1387 S. Vinnell 
Way, Room 368, Boise, Idaho 83709.

FOR FURTHER INFORMATION CONTACT: Robert Ruesink at the above address, 
208/378-5243.

SUPPLEMENTARY INFORMATION:

Background

    This notice of determination is in response to a June 29, 1995, 
U.S. Court of Appeals for the Ninth Circuit (Court) decision directing 
the Service to reconsider the listing of the Bruneau Hot Springsnail 
(Idaho Farm Bureau Federation v. Babbitt, 58 F.3d 1392 (1995)). In its 
ruling, the Court directed the Service to provide the public with ``* * 
* notice and a period in which to comment on the U.S. Geological 
Survey's (USGS) * * *'' 1993 report and ``* * * also provide the public 
with any other new information * * *'' the Service planned to consider. 
The Court further stated that the public could submit any other 
information relevant to determining whether the Bruneau Hot Springsnail 
should continue to be listed as endangered. The following determination 
is based on a review of all existing information used in the original 
1993 listing rule, and new information received since that time, 
including information contained in written comments received during 
three public comment periods, totaling 218 days.

Current Status

    Boys Malkin first collected the Bruneau Hot Springsnail in thermal 
springflows at the Indian Bathtub in upper Hot Creek along the Bruneau 
River in 1952 (Hershler 1990). The following year, W.F. Bar collected 
additional specimens, which were sent to J.P. Morrison of the U.S. 
National Museum in Washington, D.C. (now the National Museum of Natural 
History) (Hershler 1990). Taylor (1982) pursued subsequent field and 
laboratory studies of this species from 1959 through 1982. Based on 
these studies, Taylor prepared a brief physiological and biological 
description of the species and suggested the common name of the Bruneau 
Hot Spring Snail. In 1990, Robert Hershler formally described the 
species from type specimens collected from the Indian Bathtub in Hot 
Creek, naming it Pyrgulopsis bruneauensis, with a new common name of 
Bruneau Hot Springsnail (Hershler 1990).
    Adult Bruneau Hot Springsnails have a small, globose to low-conic 
shell reaching a length of 5.5 millimeters (mm) (0.22 inch (in.)) with 
3.75 to 4.25 whorls. Fresh shells are thin, transparent, white-clear, 
appearing black due to pigmentation (Hershler 1990). In addition to its 
small size (less than 2.8 mm (0.11 in.) shell height), distinguishing 
features include a verge (penis) with a small lobe bearing a single 
distal glandular ridge and elongate, muscular filament. They are 
dioecious (individuals are either male or female) and lay single round 
to oval eggs on hard surfaces such as rock substrates or other snail 
shells (Mladenka 1992).
    The species occurs in flowing thermal (hot) springs and seeps with 
water temperatures ranging from 15.7 deg. Celsius (C) (60.3 deg. 
Fahrenheit (F)) to 36.9 deg. C (98.4 deg. F) ( Mladenka and Minshall 
1996). The highest Bruneau Hot Springsnail densities (greater than 1000 
individuals per square meter (m<SUP>2</SUP>) (100 per square foot 
(ft\2\)) occur at temperatures ranging from 22.8 deg. C (73 deg. F) to 
36.6 deg. C (98 deg. F) ( Mladenka and Minshall 1996). Bruneau Hot 
Springsnails have not been located outside thermal plumes of hot 
springs entering the Bruneau River. They occur in these habitats on the 
exposed surfaces of various substrates, including rocks, gravel, sand, 
mud, algal film and the underside of the water surface (Mladenka 1992). 
However, during the winter period of cold ambient temperatures and 
icing, Bruneau Hot Springsnails are most often located on the 
undersides of outflow substrates, habitats least exposed to cold 
temperatures (Mladenka 1992). In madicolous habitats (thin sheets of 
water flowing over rock faces), the species has been found in water 
depths less than 1 centimeter (cm) (0.39 in.). Current velocity is not 
considered a significant factor limiting Bruneau Hot Springsnail 
distribution, since they have been observed to inhabit nearly 100 
percent of the available current regimes (Mladenka 1992). In a 
September 1989 survey of 10 thermal springs in the vicinity of the Hot 
Creek-Bruneau River confluence, the total number of Bruneau Hot 
Springsnails per spring ranged from 1 to 17,319 (Mladenka 1992). The 
species abundance fluctuates seasonally but is generally stable under 
persistent springflow conditions (Mladenka 1992; Robinson, et al. 1992; 
Royer and Minshall 1993; Varricchione and Minshall 1995; Varricchione 
and Minshall 1996; Varricchione and Minshall 1997). Depending on site 
conditions, abundance is influenced primarily by temperature, spring 
discharge, and chlorophyll ratios (Mladenka 1992).
    Based on the most recent survey in 1996, Bruneau Hot Springsnails 
were found in 116 of 204 small, flowing thermal springs and seeps along 
an approximately 8 kilometer (km) (5 mile (mi)) length of the Bruneau 
River in southwestern Idaho (Mladenka and Minshall 1996). Surveys 
conducted since 1991 indicate a general decline in the number of 
occupied sites from a total of 130 occupied springs to the current 116 
springs, representing a 10 percent decrease (Mladenka 1992, 1993; 
Mladenka and Minshall 1996). The majority (n = 86) of occupied springs 
are located upstream of the confluence of Hot Creek with the Bruneau 
River (Mladenka and Minshall 1996). In 1996, Bruneau Hot Springsnail 
occurred in an additional 10 spring sites at the confluence of Hot 
Creek and 20 sites downstream (Mladenka and Minshall 1996). Since 1991, 
the total number of thermal springs in the Bruneau River has decreased 
by approximately 5 percent (from 214 to 204), the number of springs 
occupied by Bruneau Hot Springsnails has decreased by 10 percent (from 
130 to 116), and the total surface area of springs occupied by Bruneau 
Hot Springsnails has decreased by 13 percent (from 496 to 430.2 
m<SUP>2</SUP> (5338.9 to 4630.7 ft<SUP>2</SUP>)) (Mladenka and Minshall 
1996).
    Total site area (including all thermal springs and seeps, occupied 
and unoccupied by Bruneau Hot Springsnails) increased by 4.3 percent 
from 1991 to 1996 (Mladenka and Minshall 1996). Most of this increase 
was due to lower flows at one unoccupied spring site, resulting in more 
exposure of thermal outflow area below Buckaroo Dam, downstream of the 
majority of the occupied springs (Mladenka and Minshall 1996). Further 
analysis of the total spring surface area shows that from 1991 through 
1996, there was a 32 percent decrease at upper (above the confluence 
with Hot Creek) occupied spring sites versus a 41 percent increase in 
lower occupied springs (Mladenka and Minshall 1996). Most of the 
thermal springs and seeps containing Bruneau Hot Springsnails are small 
and occur mainly upstream of the confluence of Hot Creek with the 
Bruneau River. From 1991 to 1996, the number of occupied sites 
decreased 20 percent (107 to 86) upstream of the confluence of Hot 
Creek with the Bruneau River, decreased 17 percent (12 to 10) at the 
confluence, and increased 45 percent (11 to 20) downstream of the 
confluence. Many of the thermal springs located in the downstream 
section are unsuitable as habitat for the Bruneau

[[Page 32983]]

Hot Springsnail, due to high temperatures (greater than 37 deg. C 
(98.6 deg. F)). Surveys completed by Mladenka and Minshall in 1993 and 
1996 found the size of occupied sites ranged from 0.1 m<SUP>2</SUP> (1 
ft<SUP>2</SUP>) to 120 m<SUP>2</SUP> (1291.9 ft<SUP>2</SUP>) in 1993 
and from 0.02 m<SUP>2</SUP> (0.22 ft<SUP>2</SUP>) to 84 m\2\ (904 
ft\2\) in 1996 (Mladenka 1993; Mladenka and Minshall 1996).
    Bruneau Hot Springsnails prefer areas of locally warm water. 
Mladenka (1992) found, however, that there is a maximum thermal 
tolerance limit of 35  deg.C (95  deg.F), and that few Bruneau Hot 
Springsnails occurred in cooler springs, with minimum temperatures to 
15.7  deg.C (60.3  deg.F). Springs with cooler minimum temperatures are 
likely warmer in the summer (greater than 20  deg.C (68  deg.F)), 
providing the species opportunities for increased growth and 
reproduction (Mladenka 1992). Temperature extremes affect both 
abundance and recruitment of Bruneau Hot Springsnails (Mladenka 1992).
    Spring sites occupied by Bruneau Hot Springsnail are located 
primarily above the high-water mark of the Bruneau River. Some of the 
Bruneau Hot Springsnail colonies are separated by distances of less 
than 1 meter (m) (3.28 feet (ft)) (Mladenka and Minshall 1996). The 
Bureau of Land Management (BLM) measured spring outflow elevations at 
12 thermal springs from November 1993 to December 1993 (J. David 
Brunner, BLM, in litt. 1994). Due to time constraints, thermal springs 
that were measured for elevations represented the upper and lower most 
springs within the Bruneau River corridor, a few thermal springs in 
between, and the Indian Bathtub spring. Spring elevations ranged from 
803.7 m (2636.9 ft) to 815.7 m (2676.1 ft) (Brunner, in litt. 1994). Of 
the 12 thermal springs measured, 2 were not occupied by Bruneau Hot 
Springsnail. The Indian Bathtub (the type locality) occurs at an 
elevation of 814.7 m (2672.9 ft) and the uppermost thermal spring site 
occurs at 815.7 m (2676.61 ft).
    The hot springs and seeps that occur along the Bruneau River are 
outflows of the Bruneau Valley geothermal aquifer (Berenbrock 1993). 
Based on studies conducted by Mladenka (1992) and Varricchione and 
Minshall (1997), seasonal fluctuations in water discharge (flow over 
rockfaces) and water temperatures occur at some occupied spring sites. 
Discharge fluctuations correspond with pumping; lower flows in the late 
spring to early fall when the need for pumping is greatest, and higher 
flows during late fall to spring when the need for pumping is lowest. 
Temperatures can affect Bruneau Hot Springsnail recruitment; 
reproduction usually occurs between 20 deg. and 35  deg.C (68 deg. and 
95  deg.F), but growth and reproduction is retarded at temperatures 
cooler than 24  deg.C (75.2  deg.F) (Mladenka 1992).
    The Indian Bathtub area (now covered with sediment) and most of the 
thermal springs along the Bruneau River upstream of Hot Creek are on 
lands administered by the BLM, while most Bruneau Hot Springsnail 
habitats downstream of the Indian Bathtub and Hot Creek are on private 
land.
    The Indian Bathtub spring and its outflow, Hot Creek, represent the 
type localities of the Bruneau Hot Springsnail. Taylor (1982) found 
that the Bruneau Hot Springsnail population and its habitat at the Hot 
Creek/Indian Bathtub spring site had been reduced by more than 90 
percent from 1954 to 1981. Taylor (1982) noted in 1981 that the 
remaining Bruneau Hot Springsnail population at the Indian Bathtub 
spring occurred on vertical rock cliffs (rockface sites) protected from 
flash flood events. Varricchione and Minshall (1997) found that ``The 
rockface sites are probably more suitable for Bruneau Hot Springsnail 
success * * *'' because they provide the necessary substrate for 
reproduction. In 1964, spring discharge at the Indian Bathtub spring 
was approximately 9,300 liters per minute (L/min) (2,400 gallons per 
minute (gal/min)). By 1978, discharge had dropped to between 503.8 to 
627.8 L/min (130 to 162 gal/min) (Young et al. 1979). By the summer of 
1990, discharge was zero during the summer and early fall (Berenbrock 
1993). Taylor (1982) speculated that this reduction in rockface seep 
flows would leave the Bruneau Hot Springsnail vulnerable to the 
occasional flash-flood events known to occur in the Hot Creek drainage.
    Today, water from the Indian Bathtub sinks below the ground surface 
and reemerges about 300 m (984.3 ft) below the bathtub area 
(Varricchione and Minshall 1997). In 1991, a flash flood event occurred 
sending large amounts of sediment into the Hot Creek drainage and 
resulting in a 50 percent reduction in the size of the Indian Bathtub 
(a portion of which is now covered by approximately 10 feet of 
sediment) (Mladenka 1992). Rockface habitat in the immediate vicinity 
of Indian Bathtub was also severely reduced and covered with sediment 
during this and other flash flood events (Mladenka 1992). Ongoing 
population monitoring studies indicate a lack of movement or 
recruitment of Bruneau Hot Springsnails back to the original Hot Creek/
Indian Bathtub sites (Varricchione and Minshall 1997). Varricchione and 
Minshall (1997) suggest several factors including unsuitable substrate 
type (primarily silt and sand, with little to no available rockface 
surfaces), weak migration abilities, fish predation, and a lack of an 
upstream colonization that may have prevented the Bruneau Hot 
Springsnails from returning to the upper Hot Creek and Indian Bathtub 
sites. Visible spring discharge at the Indian Bathtub continues to be 
low, ranging from 5.9 and 11 liters per second (0.21 and 0.39 cubic 
feet per second) and is intermittent in most years (Varricchione and 
Minshall 1997; Derrill J. Cowing, USGS, in litt. 1996).
    The Bruneau Hot Springsnails appear to be opportunistic grazers 
feeding upon algae and other periphyton in proportions similar to those 
found in their habitat (Mladenka 1992). However, Bruneau Hot 
Springsnail densities are lowest in areas of bright green algal mats, 
while higher Bruneau Hot Springsnail densities occur where periphyton 
communities are dominated by diatoms (Mladenka 1992). Diatoms may 
provide a more nutritious food source than other food types and their 
presence may explain higher snail densities in such areas (Gregory 
1983; Mladenka 1992). Bruneau Hot Springsnails may select for general 
food quality rather than selecting for individual food items. Mladenka 
(1992) noted that fluctuations in Bruneau Hot Springsnail abundance 
corresponded with changes in food quality based on chlorophyll content.
    Sexual maturity can occur within 2 months, with a sex ratio 
approximating 1:1. Reproduction occurs throughout the year except when 
inhibited by high or low temperatures (Mladenka 1992). Reproduction 
occurs at temperatures between 24 deg. to 35  deg.C (75.2 deg. to 95 
deg.F) (Mladenka 1992). At sites affected by high ambient temperatures 
during summer and early fall months, recruitment corresponds with 
cooler periods. Sites with cooler ambient temperatures also exhibit 
recruitment during the summer months. Bruneau Hot Springsnails use 
``hard'' surfaces such as rock substrate to deposit their eggs, or they 
may deposit eggs on other snail's shells when suitable substrates are 
unavailable (Mladenka 1992).
    Mladenka (1992) believed that some natural transfer of Bruneau Hot 
Springsnails may occur among sites. The mechanisms for dispersal 
possibly include waterfowl passively carrying Bruneau Hot Springsnails 
up or down the river corridor and spates (a sudden overflow of water 
resulting from a downpour of rain or melting of snow) in the Bruneau 
River that would carry Bruneau Hot Springsnails into other warm spring 
areas downstream. Thus,

[[Page 32984]]

dispersal would favor upstream to downstream genetic exchange (Mladenka 
1992).
    Common aquatic community associates of the Bruneau Hot Springsnail 
include three molluscs, Physella gyrina, Fossaria exigua, and Gyraulus 
vermicularis; the creeping water bug (Ambrysus mormon minor); and the 
skiff beetle (Hydroscapha natans) (Bowler and Olmstead 1991). In 
addition, Hot Creek and several of the thermal springs along the 
Bruneau River support populations of exotic guppies, (Poecilia 
reticulata and Tilapia sp.). Guppies were apparently originally 
released into upper Hot Creek at the Indian Bathtub, from which they 
spread downstream and into nearby thermal springs and seeps along the 
Bruneau River (Bowler and Olmstead 1991).
    The Bruneau study area, delineated by Berenbrock (1993), was 
purposely limited geographically to focus on the hydrology of the 
regional geothermal aquifer system where the effects of pumping on 
thermal springs discharge may be occurring. Specifically, the USGS 
implemented a study of the geohydrology of the Bruneau area, including 
ground water recharge, discharge, movement and hydraulic head; and 
determined the effects of ground water pumping on hydraulic heads and 
spring flows that could affect the Bruneau Hot Springsnail and its 
habitat. Thermal spring habitats of the Bruneau Hot Springsnail are 
formed as a result of water discharging from faults or fractures 
originating from the underlying, confined volcanic-rock (geothermal) 
aquifer (Berenbrock 1993). These natural, artesian vents discharge at 
the ground surface where the ground surface level or elevation is lower 
than the potentiometric or hydraulic head of the geothermal aquifer. 
Berenbrock (1993) has developed a conceptual model of the geothermal 
aquifer system that characterizes the geohydrology of the aquifer 
system in the Bruneau study area. Using both direct and indirect 
evidence, the model describes the hydraulic connection between the 
large aquifer system underlying the Bruneau study area and the series 
of thermal springflows along the Bruneau River containing Bruneau Hot 
Springsnails. The 1554 square kilometer (km\2\) (600 square mile 
(mi\2\)) Bruneau study area encompasses the Bruneau, Little and Sugar 
valleys in north-central Owyhee County and is underlain with 
hydraulically connected sedimentary and volcanic rocks that together 
form a regional geothermal aquifer.
    In general, ground water in the geothermal aquifer originates from 
natural recharge from precipitation in and around the Jarbidge and 
Owyhee mountains south of the Bruneau study area (Young and Lewis 1982, 
Mink 1984). Ground water flows northward from volcanic rocks to 
sedimentary rocks where it is discharged as either natural springflow, 
ground water well withdrawals, or leaves the area as underflow 
(Berenbrock 1993). Natural recharge to the regional geothermal aquifer 
underlying the 1554 km\2\ (600 mi\2\) Bruneau area was estimated to be 
approximately 70,281 cubic dekameters (dam\3\) (57,000 acre-feet (ac-
ft)) (Berenbrock 1993). Prior to extensive ground water development, 
approximately 12,453 dam\3\ (10,100 ac-ft) was discharged from 
springflows. The estimated recharge amount is a minimum value because 
10 percent of the contributing area was not estimated due to inadequate 
data being available (Berenbrock 1993).
    Ground water withdrawals from wells for domestic and agricultural 
purposes began during the late 1890's (Berenbrock 1993). From 1890 to 
1978, well discharge increased from zero to approximately 50,059.8 
dam\3\ (49,900 ac-ft) per year. Changes in discharge from thermal 
springs corresponds with changes in hydraulic head, which fluctuate 
seasonally and are substantially less during late summer than in the 
spring (Berenbrock 1993). Water in the volcanic-rock in the northern 
part of the study area near Hot Creek is confined by the overlying 
sedimentary rocks, with temperatures at the surface ranging from 15 
deg.C to more than 80  deg.C (59 to 176  deg.F) (Young et al. 1979).
    Berenbrock (1993) described both the geothermal aquifer as well as 
a shallow, unconfined cold-water aquifer within the upper layer of 
sedimentary rock. This ``second'' aquifer system is recharged from the 
infiltration of precipitation, streamflow, and applied irrigation 
water. Both Mink (1984) and Berenbrock (1993) indicated that there may 
be recharge from upward-moving geothermal water into the cold-water 
aquifer. Mink (1984) also believes that additional recharge to the 
shallow water aquifer may be occurring through leaks in irrigation 
wells. Mink (1984) believed that leaks from uncased or poorly cased 
wells were an additional reduction in water levels in the geothermal 
aquifer.

Previous Federal Actions

    Dr. Dwight Taylor carried out a field survey of the status of the 
Bruneau Hot Springsnail in 1981 and 1982. His status report, received 
by the Service on November 3, 1982, was the basis for the placement of 
this species on the Service's comprehensive notice of review on 
invertebrate candidate species published in the Federal Register (49 FR 
21664) on May 22, 1984. A candidate species is a species for which the 
Service has substantial information on hand to support the biological 
appropriateness of proposing to list as endangered or threatened. The 
Service first proposed the Bruneau Hot Springsnail for listing as 
endangered on August 21, 1985 (50 FR 33803). The comment period on this 
proposal, which originally closed on October 21, 1985, was extended to 
December 31, 1985 (50 FR 45443). To accommodate public hearings in 
Boise and Bruneau, Idaho, the comment period was reopened until 
February 1, 1986 (50 FR 51894). At the time of the hearings and 
subsequently, the Idaho Department of Water Resources (IDWR) and others 
questioned the Service's analysis of available scientific information. 
In particular, IDWR believed that surveys of available habitat were 
incomplete and the analysis of human induced impacts, such as pumping, 
was erroneous. To address these concerns and to solicit additional 
information, on December 30, 1986, the Service reopened the public 
comment period until February 6, 1987 (51 FR 47033).
    Following the extension of the comment period in which the IDWR 
proposed additional biological and hydrological studies in the Bruneau-
Grandview area, a decision was agreed upon by two former Idaho U.S. 
Senators and the Service to develop a multi-agency cooperative 
conservation plan for the Bruneau Hot Springsnail. In 1987, the U.S. 
Congress appropriated additional monies to the Service to fund these 
studies. Information developed from these studies was to be used to 
develop a cooperative conservation (management) plan to conserve and 
protect the Bruneau Hot Springsnail, precluding the need to list the 
species under the Act. Three agencies conducted these studies: IDWR, 
USGS, and Idaho State University (ISU). The IDWR was funded to: (1) 
prepare a Geographic Information System for the study area to provide a 
detailed information base from which to derive management decisions, 
including existing data and data to be developed by USGS and ISU; (2) 
prepare geological maps to define the bedrock geology and record the 
location, elevation, flow and temperature of area springflows; and (3) 
evaluate and analyze Federal and State laws applicable to a 
conservation plan for Bruneau Hot Springsnails and assess management 
alternatives open to the IDWR to protect Bruneau Hot Springsnail 
habitats. The USGS was

[[Page 32985]]

funded to develop and implement a three-phase ground water study of the 
Bruneau River valley and basin. The study focused on describing the 
hydrology of the regional geothermal aquifer system and associated 
thermal springs, with an overall goal to determine the cause of 
declining springflows affecting the Bruneau Hot Springsnail and its 
habitat. Finally, funds were provided to ISU to study the biological, 
ecological, and physiological needs of the Bruneau Hot Springsnail.
    The Service entered into a short-term conservation easement with 
Owen Ranches, Inc., landowners of the Bruneau Hot Springsnail's habitat 
in Indian Bathtub spring. The conservation agreement included fencing, 
through funds provided by the Service, to regulate livestock use and 
improve stream conditions. Although the agreement expired in October 
1992, the current landowner has honored the terms of the agreement and 
voluntarily excludes livestock grazing from the Indian Bathtub spring.
    On July 6, 1992, the Idaho Conservation League and the Committee 
for Idaho's High Desert filed a lawsuit over the failure of the Service 
to make a determination and publish in the Federal Register a decision 
regarding the listing of the Bruneau Hot Springsnail. To respond to the 
lawsuit, and to ensure the accuracy of any final decision concerning 
the appropriateness of listing, the Service reopened the public comment 
period to solicit any new information on October 5, 1992 (57 FR 45762), 
for a period of 30 days, and on December 18, 1992 (57 FR 60610), for a 
period of 10 days.
    A final rule listing the Bruneau Hot Springsnail as endangered, 
without critical habitat, was published in the Federal Register on 
January 25, 1993 (58 FR 5938). On February 26, 1993, the Idaho Farm 
Bureau Federation, Owyhee County Farm Bureau, Idaho Cattle Association, 
Owyhee County Cattleman's Association and Owyhee County Board Of 
Commissioners (Plaintiffs), jointly filed a Notice of Intent to 
challenge the listing. On May 7, 1993, the Plaintiffs filed a Complaint 
for Declaratory and Injunctive Relief in the U.S. District Court for 
the District of Idaho to overturn the final listing rule. On December 
14, 1993, Senior United States District Court Judge Harold L. Ryan 
issued a ruling in favor of the Plaintiffs and set aside the final 
listing rule (Judgment) for the Bruneau Hot Springsnail (Civil No. 93-
0168-E-HLR). In the Judgment, Judge Ryan stated that the Service 
committed ``* * * serious due process violations * * *'' and ``* * * 
court finds the final rule to be arbitrary, capricious, an abuse of 
discretion, and otherwise not in accordance with law.''
    The district court decision was appealed to the United States Court 
of Appeals for the Ninth Circuit by two intervening conservation 
groups, the Idaho Conservation League and Committee for Idaho's High 
Desert. On June 29, 1995, the appellate court overturned the district 
court decision and reinstated the Bruneau Hot Springsnail to the 
endangered species list. However, the appellate court concluded that 
the Service should have made the draft USGS report (i.e., Berenbrock 
1992) available for public review, as the Service relied largely on 
this report to support the final listing rule. The appellate court 
directed the Service to provide an opportunity for additional public 
comment on the final USGS report (Berenbrock 1993) and other new 
information, and to reconsider its original 1993 listing decision.
    To comply with the appellate court's direction, the Service 
published a notice on September 12, 1995 (60 FR 47339), announcing that 
the USGS report (Berenbrock 1993), and other reports and data 
pertaining to the listing of the Bruneau Hot Springsnail were available 
for public comment for 60 days, until November 13, 1995. In response to 
a request from Susan E. Buxton on behalf of her client (John B. 
Urquidi, J & J Ranches, Bruneau, Idaho), the Service, in a notice 
published on November 13, 1995 (60 FR 56976), extended the public 
comment period until December 15, 1995. Over 400 comments were received 
from individuals and agencies during this 95-day public comment period.
    Public Law 104-6 enacted by Congress on April 10, 1995, placed a 
moratorium on the expenditure of the Service's listing funds beginning 
in October 1995 that remained in effect until April 26, 1996, when 
President Clinton approved the Omnibus Reconciliation Act of 1996. As a 
result, the Service was unable to comply with the June 1995 court 
decision and complete a reconsidered listing decision. After the 
moratorium was lifted, the Service established priorities for 
completing listing actions based on interim guidance issued on March 
11, 1996 (61 FR 9651), final guidance for fiscal year 1996 on May 16, 
1996 (61 FR 24722), and final guidance for fiscal year 1997 issued on 
December 5, 1996 (61 FR 64475). These guidance documents focused the 
Service's limited listing funding on emergency listing and multi-
species final rules. Consequently, the Service took no action on the 
Bruneau Hot Springsnail during fiscal year 1996. Although listing 
priorities allowed the Service to take final action on this court 
decision beginning in fiscal year 1997, it had been over one year since 
the close of the last public comment period. Therefore, the Service 
solicited additional comments and made available for public review new 
information and other data pertaining to the Bruneau Hot Springsnail 
received since the last comment period. On January 23, 1997 (62 FR 
3493), the Service opened a second public comment period for 46 days 
until March 10, 1997. Because of requests from the High Desert 
Coalition Inc., Bruneau Valley Coalition and Quey Johns, the Service 
opened a third public comment period, for an additional 77 days, until 
June 9, 1997, in a notice published on March 25, 1997 (62 FR 14101). 
Fifteen comments were received from individuals and agencies during 
these two additional comment periods in 1997. In total, 416 comments 
were received between September 1995 and June 1997 during 3 public 
comment periods.

Summary of Comments and Recommendations

    Comments were received from 416 individuals and agencies during the 
3 public comment periods from September 1995 to June 1997 (60 FR 47339, 
60 FR 56976, 62 FR 3493, 62 FR 14101) for a total of 218 days. 
Additionally, advance notice of re-opening the comment periods was 
given to several people by telephone for the January and March 1997 
comment periods. Persons notified represented various interested 
parties in this issue including; Dick Bass, Owyhee County Commissioner; 
Tim Lowry, Chair of the Owyhee County Land Use Planning Committee 
(OCLUPC); Cindy Bachman, Chair of the Endangered Species Subcommittee 
for the OCLUPC; Eric Davis, President of the Bruneau Valley Coalition; 
and Laird Lucas, Land and Water Fund. Advance notice, including a press 
release and background information, was also sent by mail, fax and/or 
phone to Idaho Senators Larry Craig and Dirk Kempthorne, Idaho 
Representatives Mike Crapo and Helen Chenoweth, Idaho State Senator 
Laird Noh, and Idaho State Representative Golden Longhaired. Legal 
notices announcing each of the public comment periods were published in 
five Idaho newspapers: Idaho Statesman, Boise; Glenns Ferry Pilot, 
Glenns Ferry; Idaho Press Tribune, Nampa; Owyhee Avalanche, Homedale; 
and Mountain Home News, Mountain Home. Fifty-three copies of the 
Federal Register notices of public comment periods were

[[Page 32986]]

sent to various interested parties, including 7 Federal agencies, the 
8-member Idaho Water Resources Board, IDWR, Idaho Department of Fish 
and Game (IDFG), Idaho Department of Parks and Recreation (IDPR), ISU, 
the Idaho Congressional delegation, Governor Phillip Batt, State of 
Idaho elected officials including State Representatives Frances Field 
and Golden Longhaired and State Senators Laird Noh and R. Clair 
Wetherell, Elmore and Owyhee County Commissioners and 19 other 
individuals.
    The majority of the comments opposed endangered species status for 
the Bruneau Hot Springsnail--of the dissenting comments, 349 comment 
letters were derived from the same source (i.e., a form letter) 
received during the first re-opened comment period in September 1995 
and were considered together as one comment. Comments opposed to 
endangered species status were received from Idaho Governor Philip 
Batt, Idaho State Senator Grant Ipsen, IDWR, the Office of the State 
Treasurer, the Owyhee County Board of Commissioners, OCLUPC, and other 
user groups. No request for a public hearing was received.
    Comments of a similar nature or point of concern are grouped for 
consideration and response. A summary of these issues and the Service's 
response to each are discussed below.
    Issue 1: Several respondents believe that the range of the Bruneau 
Hot Springsnail is not completely known. They stated that comprehensive 
surveys have not been conducted throughout all potentially suitable 
habitat in the region and one study (Mladenka 1995) surveyed fewer 
sites than previous surveys. Because it is believed that the Bruneau 
Hot Springsnail has stabilized (based on studies from 1992 through 
1996) or appears to be increasing in certain areas, some respondents 
stated that the species is not truly endangered. Also, some respondents 
believe that the fish predation study was inadequate to determine if 
fish predation is a threat to the Bruneau Hot Springsnail. It is also 
believed that Bruneau Hot Springsnails are highly adaptable and can 
easily relocate. For example, a colony is being kept in an aquarium at 
the BLM, Boise District office indicating that the species may be 
adaptable to environments outside their thermal spring habitats in the 
Bruneau River.
    Service Response: Snail surveys have been conducted in Idaho and 
elsewhere since 1994 (Frest, in litt. 1994; Frest and Johannes 1995; 
Robert Hershler, Smithsonian Institution, in litt. 1994, 1995). Surveys 
included regions within the Great Basin, including Utah, Nevada and 
eastern Idaho, and the Interior Columbia Basin. Thermal springs along 
the Bruneau River have been re-surveyed specifically for additional 
Bruneau Hot Springsnail sites in 1993 and 1996 (Mladenka and Minshall 
1993, 1996). No other new information has been presented to the Service 
to substantiate the claim that the Bruneau Hot Springsnail is not 
endemic to springs along Hot Creek and the Bruneau River drainage. No 
historic collections of this species have been verified in other areas 
of the United States. In 1991, Mladenka (Mladenka 1992) described the 
known range of the Bruneau Hot Springsnail as an 8 km (5 mi) reach of 
the Bruneau River, above and below the confluence of Hot Creek. Other 
studies outside the Bruneau River corridor (Terrence J. Frest, DEXIS, 
in litt. 1994; Frest and Johannes 1995; Hershler in litt. 1994, 1995) 
have not located additional sites for the Bruneau Hot Springsnail.
    Studies conducted by Mladenka (1992) and Mladenka and Minshall 
(1993; 1996) indicate a general decline in the total number of thermal 
springs along the Bruneau River, the number of springs occupied by 
Bruneau Hot Springsnails and a general decline in densities of Bruneau 
Hot Springsnails (see BACKGROUND section for further discussion). 
Mladenka and Minshall (1993) found dead Bruneau Hot Springsnails at one 
previously occupied spring site where flows had recently diminished and 
nine additional spring sites showed noticeable reductions in discharge. 
From 1991 to 1996, the total number of springs had been reduced from 
214 to 204. The number of springs occupied by Bruneau Hot Springsnails 
had declined from 130 to 116. Additionally, although Mladenka and 
Minshall's (1993; 1996) population densities were only estimates, there 
appears to be a trend in declining densities overall that corresponds 
to the decline in the number of occupied spring sites.
    While two of the three populations of the Bruneau Hot Springsnail 
monitored since 1991 appear to be stable (Varricchione and Minshall 
1997), the Service believes that all remaining habitat for this species 
is threatened by those factors described in this rule (Factors A and E, 
Summary of Factors Affecting the Species). Given that all thermal 
springs along this reach of the Bruneau River arise from a single 
regional geothermal aquifer (Berenbrock 1993), Bruneau Hot Springsnails 
and their habitats continue to be threatened by long-term declines in 
the Bruneau Valley aquifer. The Bruneau Hot Springsnail, endemic to 
this small geographic area in southwestern Idaho, and its habitat are 
totally dependent on remaining thermal springflows originating from 
this single source of ground water. As noted by Varricchione and 
Minshall (1997), ``Given enough reduction in springflow, Bruneau Hot 
Springsnail populations (at the two monitored sites) could be reduced 
to abundances that are too small to remain viable.''
    Regarding the comment that Mladenka's 1995 survey study looked at 
fewer sites than previous surveys, the purpose of the study was to 
survey the macroinvertebrate assemblages in several thermal springs 
along the Bruneau River in the vicinity of its confluence with Hot 
Creek. The Service funded this study to further define the species 
richness of the thermal springs occupied by the Bruneau Hot 
Springsnail. Due to the replication of species found in several of the 
initial hot springs sampled, the Service made a decision that sampling 
fewer sites would be representative of all thermal springs along the 
Bruneau River. This study, therefore, was not strictly a Bruneau Hot 
Springsnail survey.
    A study to determine the effects of fish predation on the Bruneau 
Hot Springsnail was conducted by Varricchione and Minshall (1995a). The 
study focused on two exotic species of fish, Gambusia and Tilapia, in 
the Hot Creek drainage. Hot Creek no longer has a viable population of 
Bruneau Hot Springsnails (too few in total numbers of individuals), and 
no Bruneau Hot Springsnails were detected in the diet of these two 
species of fish (Varricchione and Minshall 1995a). Mladenka (1992) 
however, found Gambusia aggressively preying upon Bruneau Hot 
Springsnails in a controlled (aquarium) environment. Additionally, a 
commenter indicated that the time of year that the fish predation study 
was undertaken was inappropriate since water temperatures may have been 
too cold and Bruneau Hot Springsnails are less available during winter 
conditions. The fish predation study was undertaken during the winter 
months, which for the Hot Creek site is the optimal time for 
reproduction and recruitment of Bruneau Hot Springsnails. Water 
temperatures in the summer reach or exceed the thermal maximum 
temperature due to exposure to higher ambient temperatures 
(Varricchione and Minshall 1997). During periods of higher 
temperatures, the species retreats to areas protected from high ambient 
temperatures among sedges, underneath rocks or under superficial algal 
mats (Mladenka 1992). Pending further study,

[[Page 32987]]

the Service considers the presence of these two exotic fishes a 
possible threat to Bruneau Hot Springsnails residing in Hot Creek and 
at other thermal spring sites along the Bruneau River.
    Bruneau Hot Springsnails may be limited in their ability to 
relocate and re-colonize new spring sites. The parameters required for 
acceptable habitat are specific in nature, i.e. minimum and maximum 
temperatures of 7.6 and 35.7 deg. C (45 and 96 deg. F) respectively and 
adequate substrate and spring discharge (Varricchione and Minshall 
1997). Mladenka (1992) found that reproduction occurred at temperatures 
between 20 and 35 deg. C (68 and 95 deg. F), with a noted decline in 
reproduction (and hence recruitment) at 24 deg. C (75.2 deg. F). Few 
springs along the Bruneau River meet these requirements. Mladenka 
(1992) indicated that dispersal likely occurs through spates within the 
Bruneau River corridor.
    Since approximately 1985, the BLM has maintained a population of 
Bruneau Hot Springsnails in an aquarium. The environment is being 
artificially maintained using an aquarium heating device and periodic 
additions of distilled water, with occasional augmentations of water 
from Hot Creek. Due to the regular maintenance required of this system, 
the Service does not consider this population a viable and sustainable 
population under the definition of recovery for endangered species.
    Issue 2: Many respondents believe that the Service did not use the 
best or sufficient scientific information in listing this species. 
Other comments indicated that few sites have been surveyed for the 
presence of the Bruneau Hot Springsnail and that the surveys were 
biased against farming and ranching. Other concerns were that 
monitoring has not been adequate to assess the status of the species. 
Many respondents believe that this species is widespread and additional 
populations exist elsewhere that have not been reported. Several 
respondents also stated that because Bruneau Hot Springsnail 
populations are stable or increasing at some sites, listing is not 
appropriate. One commenter indicated that because monitoring was 
terminated in 1993, data collected subsequently was not reliable.
    Service Response: The Service believes that the decision to retain 
the Bruneau Hot Springsnail as endangered is based on the best 
available scientific information. The Service is unaware of any bias on 
the part of the researchers involved in biological or ground water 
studies. The Service believes that all research has been conducted in a 
professional and credible scientific manner.
    Ground water studies conducted by the USGS, funded by the Service 
beginning in 1989, with monitoring of water levels, spring discharge 
and pumping rates continuing until September 1996. Biological surveys 
and monitoring for the Bruneau Hot Springsnail, funded by the BLM and 
the Service, have been ongoing through ISU from 1991 through 1996. 
Although Bruneau Hot Springsnails have been located at new thermal 
spring sites, all these sites are within the known range of the 
species, an 8 km (5 mi) reach of the Bruneau River (Mladenka and 
Minshall 1993, 1996) and all these thermal springs are subject to 
similar threats affecting the single source geothermal aquifer 
providing the necessary springflows. It has been documented that from 
1992 to 1996, there has been an overall reduction in the number of 
thermal springs along the Bruneau River; the number of thermal spring 
sites occupied by Bruneau Hot Springsnails; and a reduction in the 
overall densities of Bruneau Hot Springsnails at the known occupied 
sites (see BACKGROUND section and issue #1 for further discussion). As 
already discussed, thermal springs along the Bruneau River are 
influenced by activities affecting the condition of a single geothermal 
aquifer. The decision to continue the listing of the Bruneau Hot 
Springsnail is appropriate based primarily on continued habitat loss 
and modification resulting from reduced thermal springflows.
    As previously stated in the issue #1 response, snail surveys have 
been conducted in Idaho and elsewhere since 1994 (Frest, in litt. 1994; 
Frest and Johannes 1995; Hershler, in litt. 1994, 1995). These surveys 
included regions within the Great Basin, including Utah, Nevada and 
eastern Idaho, and the Interior Columbia Basin. Thermal springs along 
the Bruneau River have been re-surveyed specifically for additional 
Bruneau Hot Springsnail sites in 1993 and 1996 (Mladenka and Minshall 
1993, 1996). No other new information has been presented to the Service 
to substantiate the claim that the Bruneau Hot Springsnail is not 
endemic to springs along Hot Creek and the Bruneau River drainage. No 
historic collections of this species have been verified in other areas 
of the United States. The Bruneau Hot Springsnail is part of a small 
group of thermophile species (requiring high temperatures for normal 
development), most or all of which are highly endemic (Frest and 
Johannes 1995). In addition, most taxa in the Pyrgulopsis genus are 
endemic to a single spring or spring groups widely separated from each 
other geographically (Frest and Johannes 1995).
    In regard to the comment about an abrupt halt to monitoring efforts 
* * * ``In light of Mr. Lobdell's abrupt termination of the 1992 data 
collection for the (Bruneau Hot Springsnail), reliance on the ISU 
Stream Ecology Center Studies--all referencing the 1992 data gathering 
activities--are suspect.'', the Service believes this refers to a brief 
halt in 1992-1993 data gathering as a result of the 1993 listing of the 
Bruneau Hot Springsnail, at which time the species was given the full 
protection of the Act. The Service issues permits to individuals 
wishing to conduct research to further the recovery of the species. 
Once the necessary permitting requirements under section 10 of the Act 
were satisfied, data collection for the 1992-1993 season continued and 
was completed. The Service is satisfied with the reliability of the 
data.
    Issue 3: Some respondents believed that the Bruneau Hot Springsnail 
is not native or does not appear to have any ecological significance 
and therefore should not be listed.
    Service Response: Congress directed that, in determining whether a 
species warrants listing under the Act, the Service may consider only 
the five factors set forth in section 4(a)(1) of the Act. These factors 
do not include the ``ecological significance'' of the species; hence, 
the Service has no authority to decline to list a species on the basis 
of whether or not the species is considered ecologically significant.
    Issue 4: Many respondents believe that the hydrologic studies 
conducted to date are inconclusive with regard to determining that 
water withdrawals cause the decline in the geothermal aquifer. Many 
noted that the 1993 USGS report (Berenbrock 1993) is incorrect or 
incomplete because it does not account for the effects of climatic 
(e.g., drought) or geologic factors that may be affecting springflow 
and well discharge characteristics and Bruneau Hot Springsnail 
population estimates, even accounting for the significant reductions in 
pumping in recent years. Recent reports (Cowing, in litt. 1996; Karl J. 
Dreher, IDWR, in litt. 1997) indicate that water levels in the aquifer 
have increased. It was also suggested that studies on the dynamics of 
the local aquifer system should be subject to independent peer-review. 
Many respondents believe that the recharge calculation error found in 
the draft USGS report (Berenbrock 1992) is still unresolved and should 
be corrected

[[Page 32988]]

before further assessment of the aquifer can occur.
    Service Response: Berenbrock (1993) indicated that water levels and 
spring discharge were likely not related to recent climatic (drought) 
conditions. It has been established that recharge to the aquifer is 
related to precipitation in the Jarbidge Mountain range (Berenbrock 
1993). The effect of this recharge is over several thousand years, as 
evidenced by the age of the water currently residing in the aquifer. 
Although the amount of withdrawals has been reduced since 1981, from 
61,526.7 dam<SUP>3</SUP> (49,900 ac-ft) to a low of 40,935.6 
dam<SUP>3</SUP> (33,200 ac-ft) in 1987 (1995 levels were 45,374.4 
dam<SUP>3</SUP> (36,500 ac-ft)), spring discharge and available Bruneau 
Hot Springsnail habitat have continued to decline (Cowing, in litt. 
1996). Berenbrock (1993) calculated natural recharge to the geothermal 
aquifer to be 70,281 dam<SUP>3</SUP> (57,000 ac-ft) (Berenbrock 1993). 
This value does not account for the underflow (recharge) drained by the 
Little Jacks and Logan creeks, which represents 10 percent of the 
contributing area. Therefore, the natural recharge estimated by 
Berenbrock (1993) is a minimum value only. Total estimated discharge 
from springs prior to extensive ground water development was 
approximately 12,453 dam<SUP>3</SUP> (10,100 ac-ft). Between 1978 and 
1991 total well withdrawals were 673,218 dam<SUP>3</SUP> (546,000 ac-
ft), averaging 51,786 dam<SUP>3</SUP> (42,000 ac-ft) per year.
    The Service concurs with Berenbrock's (1993) conclusions and with 
the results of the continued monitoring efforts by USGS through 
September 1996 (Cowing, in litt. 1996). The conclusions reached by 
Berenbrock and the monitoring data demonstrate a relationship between 
water levels in the aquifer, seasonal variations in water levels, 
spring discharge, and pumpage rates. Annual pumpage rates are related 
to climatic conditions in the Bruneau Valley, i.e., well withdrawals 
increase when spring precipitation is low. Spring discharge exhibits a 
similar seasonality to water level measurements June through September, 
reflecting the amount of pumping through the irrigation season (Cowing, 
in litt. 1996). A relation between potentiometric levels and spring 
discharge has persisted through the drought and into ``normal'' 
precipitation cycles. As indicated above, although ground water levels 
may be depleted fairly rapidly by human utilization for agricultural or 
other uses, the geothermal aquifer recharge typically occurs very 
slowly and from a source well outside the Bruneau area (see Factor A of 
the Summary of Factors Affecting the Species section for further 
discussion). Therefore, although there was a slight increase in water 
levels at some well monitoring sites in 1996, and a slight increase in 
spring discharge at some springs monitored at the same time, the 
general trend for Bruneau Hot Springsnail habitat remains in decline 
and water levels in the geothermal aquifer are low when compared to 
historic levels. Of the 19 wells within the Bruneau study area, 11 
wells have continued to show slight declines in water levels, and 6 
have shown slight increases in water levels (2 wells were difficult to 
determine from graphs) (Cowing, in litt. 1996) . In general, water 
levels in the geothermal aquifer continue to decline.
    A relation between hydraulic head and spring discharge has been 
established, the Service has not received any new information 
indicating a change in this relation between total aquifer discharge 
(including spring discharge, underflow and well withdrawals) and 
recharge. The question of what levels of pumping can occur without 
further declines in aquifer water levels and thermal spring flows has 
not been defined.
    The USGS report and document review process consists of a three-
step process: (1) local (originating office) review includes review by 
2 district (Idaho) colleagues that are experts in the technical 
information contained in the report, review by the section supervisor 
and editorial review by an experienced editor; (2) regional USGS review 
includes another specialist review by a technical expert in the 
discipline of the report and a second editorial review; and (3) USGS 
headquarters review involves a third technical reviewer and a third 
editorial review. The final document is then signed by the Director of 
the USGS. In the case of Berenbrock (1992), IDWR was provided a copy of 
the draft document prior to the Service completing the original listing 
rule. IDWR used the information in preparing their contractual report 
submitted to the Service entitled ``Analysis of Management Alternatives 
and Potential Impacts on Ground-Water Development Due to Proposed 
Endangered Species Classification of The Bruneau Hot Springs Snail'' 
(IDWR 1992).
    The recharge ``error'' referred to by comments relates to a 
miscalculation of natural recharge using Darcy's equation in the draft 
1992 Berenbrock report. The error in natural recharge occurred due to a 
miscalculation in average hydraulic conductivity (Jerry Hughes, USGS, 
in litt. 1993). The final (1993) version of the Berenbrock report 
(pages 23 through 26) incorporates the correct information for 
calculating natural recharge by another method. Therefore, the Service 
believes that the issue of ``errors'' in the draft report has been 
resolved.
    Issue 5: Some respondents believed that there is no evidence that 
reducing agricultural or domestic water use will actually benefit 
Bruneau Hot Springsnail habitat. Other comments suggested that casing 
deep wells to reduce leakage would contribute to water conservation and 
reduce or remove the need to list this species. Two respondents 
referred to the disappearance of ``Deer Water'' in Hot Creek (as an 
indicator that declining water levels have occurred in the historic 
past). It was also speculated that stabilization of the aquifer will 
occur at some point in the future.
    Service Response: The Service believes that on-going, unrestricted 
ground water pumping has contributed to the loss of Bruneau Hot 
Springsnail thermal spring habitats in the Bruneau River drainage. 
Protection of the remaining Bruneau Hot Springsnail habitat can only be 
achieved through cooperative efforts with the State of Idaho and 
others, which address water levels within the geothermal aquifer and 
the maintenance of thermal springflows.
    It is recognized that the geothermal aquifer in the Bruneau Valley 
is a complex, multi-layered aquifer, and that water leakage may occur 
in a stepwise fashion upward between permeable zones through faults, 
fractures, and wells (Kimball E. Goddard, USGS, in litt. 1995; IDWR 
1992; Mink 1984; Leland R. Mink, IWRRI, in litt. 1995) (see BACKGROUND 
section for further discussion). The ground water reservoir in the 
aquifer functions as a three-dimensional flow system: (1) water flows 
northward from the recharge area in the Jarbidge and Owyhee mountains, 
where it is discharged as springs and as seepage to streams or leaves 
the area as ground water underflow; (2) in recharge areas there is a 
downward component of water movement; and (3) in discharge areas there 
is an upward component (Berenbrock 1993). In 1984, the Idaho Water 
Resources Research Institute (IWRRI), along with the University of 
Idaho, proposed an investigation of geothermal wells to determine 
whether older or uncased wells are losing water to the upper aquifer 
and determine the feasibility and estimated cost of repairing those 
wells (Mink and Lockwood 1995). Mink and Lockwood (1995) indicated that 
Ron Hiddleston (drilling expert in Mountain Home) believed that ``* * * 
there are very few properly constructed wells in the Bruneau Valley.'' 
Mink and Lockwood (1995) also found that Merion Kendall

[[Page 32989]]

(in 1989) estimated that 77 percent of the wells in the Bruneau area 
had the potential for interaquifer flow. Mink and Lockwood (1995) 
concluded that water is moving horizontally out of wells into 
shallower, more permeable zones. It was not determined what volume of 
water could be moved from the deeper aquifer (geothermal) to the 
shallower aquifer (cold-water) system. In 1995, the Service provided 
$2,500 to IWRRI to evaluate the cross-flow potential of individual 
wells. It was not until the summer of 1997 that IWRRI was able to 
obtain permission to investigate a single well. By the close of the 
public comment period in June 1997, the Service had not received a 
report from IWRRI on the results of their limited investigation. The 
Service agrees with others (Goddard 1995; IDWR 1992; Mink 1984, Mink 
and Lockwood 1995) who believe that leakage from some agricultural 
wells may be a contributing factor in the loss of water from the 
geothermal aquifer.
    No information has been provided to the Service regarding the 
specifics of the disappearance of ``Deer Water'' and there has been no 
reference to ``Deer Water'' in previous studies. Therefore, the Service 
is unaware of a prehistoric disappearance of ``Deer Water'' on Hot 
Creek.
    Although the Service agrees that ``stabilization'' of the aquifer 
may occur some time in the future, it is uncertain that 
``stabilization'' can occur before there is further loss of thermal 
spring habitats. A relationship between hydraulic head and spring 
discharge has been established; the Service has not received any new 
information indicating a change in this relation between total aquifer 
discharge (including spring discharge, underflow and well withdrawals) 
and recharge. The question of what levels of pumping can occur without 
further declines in aquifer water levels and thermal spring flows has 
not, to our knowledge, been defined. If water levels in the geothermal 
aquifer system in the Bruneau area continue to decline, the Service 
believes that thermal springs will eventually cease to flow and Bruneau 
Hot Springsnails and their habitat will be eliminated.
    Issue 6: Many respondents stated that existing regulatory 
mechanisms are sufficient to protect this species in lieu of listing. 
For example, the Bruneau Valley Coalition has developed a habitat 
conservation plan; the Governor of Idaho stated that ``as soon as the 
bull trout conservation plan is complete, (he) will turn the State's 
attention to developing a conservation plan for the (Bruneau Hot 
Springsnail)'' (Phillip E. Batt, Governor of Idaho, in litt. 1995); and 
the Idaho State Legislature has developed State law to prevent the 
waste or ``mining'' of ground water (Dreher, in litt. 1997). Dreher (in 
litt. 1997) asserted that water withdrawals have never exceeded 
61,526.7 dam<SUP>3</SUP> (49,900 ac-ft), which is below the natural 
recharge calculated by USGS and therefore, concern for further loss of 
thermal springs is probably not warranted. Many respondents believe 
that listing the Bruneau Hot Springsnail would adversely affect local 
and regional planning efforts that are currently in progress. For 
example, the IDWR has designated the area as a Ground Water Management 
Area (GWMA), which should provide protection for the aquifer and ensure 
adequate flows for the Bruneau Hot Springsnail. IDWR has presented 
alternatives to listing that would protect Bruneau Hot Springsnail 
habitat and these alternatives have been incorporated into the Owyhee 
County Land Use and Management Plan.
    Service Response: IDWR can regulate ground water development in the 
Bruneau area. Through this regulatory authority, IDWR may designate an 
area as a GWMA if it has been determined that a ground water basin or 
part thereof may be approaching the conditions of a ``critical ground 
water area'' (I.C. 42-233a et seq.). Under this designation, the 
Director of IDWR may approve applications for permits only after it is 
determined that sufficient water is available (I.C. 42-233a et seq.). 
In 1982, the IDWR established the Bruneau-Grandview area as a GWMA 
(Dreher in litt. 1997). Since that time, no new water withdrawal 
permits have been issued for agricultural use. The Director may also 
determine whether or not a ground water supply is insufficient to meet 
demand within a designated water management area and will order those 
water rights holders on a time priority basis to cease or reduce 
withdrawal of water until it is determined that there is sufficient 
ground water (I.C. 42-233a et. seq.). The State of Idaho has determined 
that a level of 61,526.7 dam<SUP>3</SUP> (49,900 ac-ft) does not 
constitute ``mining'' of ground water in the Bruneau-Grandview area. 
This amount of withdrawal was reached in 1981 (Cowing, in litt. 1996). 
Withdrawals have ranged from 56,471 to 40,935.6 dam<SUP>3</SUP> (45,800 
to 33,200 ac-ft), with an average amount of 45,390 dam<SUP>3</SUP> 
(36,813 ac-ft) over a 13-year period from 1982 to 1995, excluding 1994 
(Cowing, in litt. 1996). Although withdrawal rates have remained below 
the 1981 level, aquifer levels continued to decline through 1994, with 
only a slight increase in water levels occurring in early 1996. At this 
time, pumping rates during the late 1996 to early 1997 irrigation 
season are unknown. Pumping rates have been similar to 1995 levels due 
to higher precipitation during the 1996 irrigation season. To date, the 
State of Idaho has not taken any action to implement legislation 
intended to control existing withdrawals (Dreher in litt. 1997).
    In 1992, IDWR developed four management alternatives to preclude 
the listing of the Bruneau Hot Springsnail. Three of the alternatives 
were included by the Owyhee County Commissioners (OCC) in the Owyhee 
County Interim Comprehensive Land Use and Management Plan (OCC 1993). 
The preferred alternative by both IDWR and OCC was Alternative A, to 
``Do Nothing.'' In support of Alternative A, IDWR (1992) stated that 
``it is not reasonable to assume that all spring flows are declining or 
that water levels will decline at the same rate as monitored springs 
and wells.'' IDWR further stated that there are ``no data to support 
how much of (the) decline (in spring flow) is related to the extended 
drought in southern Idaho and how much might be related to ground water 
withdrawals.'' IDWR also asserted that ``with the existing reduced 
level of ground water withdrawal, due in large part to the Conservation 
Reserve Program, aquifer water levels would normally be expected to 
reduce their rate of decline if drought conditions were no longer 
present.'' IDWR assumed that only those springs with elevations lower 
than Indian Bathtub are being affected by reduced spring flows and that 
at some point in the future, when the aquifer stabilizes, these springs 
also will stabilize. As indicated under issue #4 the Service believes 
that there is a strong relationship between water levels in the 
geothermal aquifer, spring discharge and ground water pumping rates, 
with short-term climatic patterns not a significant factor in the long-
term declines that have occurred. Until the trend of declining thermal 
springflows is reversed, the Bruneau Hot Springsnail will remain 
endangered because of threats to its habitat.
    In 1995, the State of Idaho authorized the creation and supervision 
of Water Management Districts (WMD) by IDWR (Idaho Code (I.C.) 42-705 
et seq.). Activities to be performed include monitoring of ground water 
levels at ground water diversions before and during pumping activities; 
and immediate reporting to the Director any water diversions that may 
have been diverted without a water right or in violation of a water 
right. To date, the Bruneau/Grandview area has not been

[[Page 32990]]

designated as a WMD. The Service is aware of only one WMD to be 
developed for the State of Idaho--for the Eastern Snake River Plain.
    The Service recognizes that the water conservation and other 
measures could be implemented to the benefit of Bruneau Hot Springsnail 
habitat in this region, and finds that participation in these programs 
could contribute significantly to reducing some of the short-term 
threats to the Bruneau Hot Springsnail. However, only the State of 
Idaho has the regulatory authority to set limits on the development of 
new wells, impose conservation measures, and require meters on all 
wells in the Bruneau/Grandview area (IDWR 1992). Other than the 
restriction mentioned above for new agricultural use wells, no other 
regulatory measures have been exercised by IDWR. It should be noted 
that as of June 9, 1997, and the implementation of the Conservation 
Reserve Program (CRP) and the restriction of no new agricultural use 
wells, there has not been any significant improvement to water levels 
in the geothermal aquifer.
    In 1995, the Bruneau Valley Coalition developed a proposed 
``Habitat Maintenance and Conservation Plan for the Bruneau Hot 
Springsnail'' (Plan). The Plan proposed two phases of implementation. 
Phase 1 had four tasks including: (1) collection and analysis of 
existing data; (2) downhole geophysical testing to identify wells that 
may have subsurface leakage problems; (3) development of corrective 
action plans and cost estimates for repair of leaking wells; and (4) 
identification of additional wells that may be impacting Bruneau Hot 
Springsnail habitat. Phase 2 included six tasks: (1) implementing 
corrective actions, such as casing, grouting, sealing and/or abandoning 
specific wells identified in Phase 1; (2) information and education 
programs targeting congressional offices, farm and ranch families and 
other entities to support water conservation programs such as the 
Conservation Reserve Program; (3) locate private abandoned leaking 
wells previously unaccessible due to private property access 
constraints; (4) investigate water transfers, including swapping ground 
water for early season surface flood water; (5) develop an alternative 
water supply for the Indian Bathtub spring; and (6) evaluate the 
feasibility of transplantation sites for new Bruneau Hot Springsnail 
colonies. On March 3, 1995, the Service met with Jim Yost, representing 
the Bruneau Valley Coalition, to discuss our comments and suggestions 
regarding the proposed Plan. In summary, the Service noted that the 
Plan: (1) was limited to a 6-mile radius from the Indian Bathtub spring 
and failed to address other critical ground water withdrawal areas; (2) 
appears to be a ``more studies'' approach rather than corrective 
actions; (3) does not provide information on the amount of water that 
would be conserved if a well was repaired or provide an accounting 
system for monitoring the success of well repairs; and (4) needed to 
state a goal that reflected the removal of threats to the species or 
that the aquifer would be maintained at a specific level, measured by 
water levels within specific wells. Additionally, the Plan makes no 
commitment on the part of any of the signatory parties to implement 
specific actions. The Service has not been contacted subsequently and 
is unaware whether the Bruneau Valley Coalition's Plan has been 
finalized or approved by any of the affected interested parties.
    During the September 1995 public comment period, the Governor of 
Idaho stated that ``as soon as the bull trout conservation plan is 
complete, (he) will turn the State's attention to developing a 
conservation plan for the (Bruneau Hot Springsnail)'' (Phillip E. Batt, 
Governor of Idaho, in litt. 1995). As of June 9, 1997, no conservation 
plan for the Bruneau Hot Springsnail had been initiated or developed by 
the Governor's office. On August 11, 1997, the Governor's office 
invited several agencies and individuals to participate in a Bruneau 
Hot Springsnail Conservation Committee. Two meetings have been 
organized by the State to discuss and update the Bruneau Hot 
Springsnail biological information. Actions to remove the threats to 
the species have not been discussed. The Service strongly supports this 
effort and will continue to participate in these efforts by the State.
    Issue 7: Many respondents indicated that the Service should 
consider the following actions for restoration/recovery of the species 
to preclude listing of the species: transplant the Bruneau Hot 
Springsnail back to Hot Creek; exchange water rights with BLM-held 
water rights to benefit the Bruneau Hot Springsnail; substitute surface 
water for the loss of ground water; mitigate the effects of flash 
flooding in Hot Creek; develop individual Habitat Conservation Plans. 
It was also noted that the ban on new wells and rehabilitation of new 
wells has occurred and therefore additional protection for the Bruneau 
Hot Springsnail is unnecessary.
    Service Response: According to section 2(b) of the Act, ``* * * the 
purposes of this Act are to provide a means whereby the ecosystems upon 
which endangered species and threatened species depend may be 
conserved.'' Although captive propagation and translocation can be 
valid conservation tools in recovery efforts for some species, the 
Service maintains that in the case of the Bruneau Hot Springsnail, 
these measures would not contribute to secure, self-sustaining 
populations in their natural habitat. Translocation can only occur into 
native, secure habitats; therefore, the question of adequate thermal 
springflows must be addressed prior to any translocation efforts. The 
Service acknowledges that restoring springs flows within the historic 
range (i.e., Hot Creek) of the Bruneau Hot Springsnail would contribute 
to recovery of this taxon. Without the assurance of adequate 
springflows in Hot Creek or at the Indian Bathtub spring, actions to 
remove sediment from the Indian Bathtub would not provide for improved 
habitat conditions at that site. Water rights exchange, surface water 
substitution, development of Habitat Conservation Plans and other 
actions that may improve habitat suitability for the Bruneau Hot 
Springsnail will be addressed during during the development of a 
recovery plan for this species.
    The Service has acknowledged that in 1982 IDWR instituted a ban on 
all new agricultural (nondomestic) wells. We are unaware however, of 
any rehabilitation efforts for leaking of existing wells (see issue #4 
for further discussion of well leakage). The persistent trend in 
decline of the geothermal aquifer continues to be the primary concern 
for the survival and recovery of the Bruneau Hot Springsnail.
    Issue 8: A few comments indicated that funding has been provided 
for Bruneau Hot Springsnail conservation and that an accounting of that 
funding should be provided. The Bruneau Valley Coalition questioned 
what the Service has done specifically to protect the Bruneau Hot 
Springsnail.
    Service Response: The U.S. Congress appropriated money to the 
Service to fund studies starting in 1987. Information gained from the 
studies was to be used to develop a cooperative conservation 
(management) plan to aid in the long-term conservation and protection 
of the Bruneau Hot Springsnail. To date a conservation plan has not 
been finalized. The three entities involved in the studies for the 
cooperative conservation planning efforts included the IDWR, USGS, and 
ISU. The IDWR was to accomplish three primary tasks through the 
studies: (1)

[[Page 32991]]

prepare a Geographic Information System (GIS) for the study area; (2) 
prepare geological maps to define the bedrock geology and record the 
location, elevation, flow and temperature of area springflows; and (3) 
evaluate and analyze Federal and State laws applicable to development 
of a conservation plan for the Bruneau Hot Springsnail and assess 
management alternatives open to IDWR to protect the species habitats. 
The Service also provided funds for the USGS to develop and implement a 
three-phase ground water study of the Bruneau River valley and basin. 
The study focused on the hydrology of the regional geothermal system 
and surrounding hot springs, with an overall goal to determine the 
cause of declining springflows affecting the Bruneau Hot Springsnail. 
Finally, the Service provided funds to the Stream Ecology Center, ISU, 
to study the biological, ecological, and physiological needs of the 
Bruneau Hot Springsnail. The Service also entered into a short-term 
conservation agreement with Owen Ranches, Inc., owners of much of the 
snail's habitat in Hot Creek and the Indian Bathtub springs. Terms of 
the agreement included fencing to regulate livestock use. Expiration of 
this agreement coincided with the completion of the hydrologic studies 
by USGS.
    In 1990 through 1996, subsequent to the funding provided by the 
Congressional appropriation, the Service has provided funding to USGS, 
ISU, and IWRRI to continue various monitoring efforts. From September 
1994 through September 1996, the Service provided funds to the USGS to 
conduct the following action items on an annual basis: (1) monthly 
water-level measurement for 11 wells in the Bruneau area; (2) semi-
annual water-level measurement for one well; (3) operation of 
continuous water-level recorders in 6 wells; (4) monthly discharge 
measurements for 8 springs; (5) annual ground water pumpage in Sugar, 
Bruneau, and Little Valleys; and (6) flume construction for spring 
discharge measurement (first year only). Due to Service-wide funding 
shortfalls, these funds were unavailable after September 1996.
    The Service also provided: funding to IWRRI to develop preliminary 
information regarding well-leakage (see issue #4 for more detailed 
information); funding to ISU in 1993 and 1996 to re-survey Bruneau Hot 
Springsnail habitats along the Bruneau River; and additional funding to 
ISU in 1994 to conduct a thermal spring invertebrate survey along the 
Bruneau River.
    In addition to the Congressional appropriation and Service funding, 
the BLM has provided challenge cost-share funding from 1994 through 
1997 to ISU to continue biological/ecological studies on the Bruneau 
Hot Springsnail at three monitoring sites. The BLM also funded the 
installation of additional fencing around Hot Creek drainage on the 
west side of the Bruneau River and cadastral surveys (elevational 
measurements) of selected springs in the Bruneau River. Maintenance of 
the fencing along the west side of the Bruneau River is being provided 
by the permittees in the affected allotments. An Environmental 
Assessment for fencing on the east side of the Bruneau River has been 
written, but is currently under protest by the Idaho Watershed Project. 
Until the concerns by this group are resolved, the BLM has provided 
upland watering for livestock as well as requiring permittees to 
provide weekly riding in the Bruneau River canyon and removal of any 
livestock that may stray into the river corridor.
    Issue 9: Many respondents were concerned with the effect of the 
Conservation Reserve Program (CRP) reductions and asked whether the 
Service has consulted on proposed requirement and eligibility changes 
in the program. It was also asserted that the Service should encourage 
more participation in the CRP.
    Service Response: As discussed under Factor A, ``Summary of Factors 
Affecting the Species'', the loss of participation in the CRP could 
have a serious effect on the continued withdrawal of water from the 
geothermal aquifer. As further discussed in issues #2, 4, 5 and Factors 
A and D in ``Summary of Factors Affecting the Species'' of this rule, 
water withdrawals have an effect on the continuing decline of the 
geothermal aquifer, and consequently the loss of thermal springs along 
the Bruneau River. In spite of the enrollment of nearly 6,880 acres of 
Bruneau area croplands in the CRP since 1981, water levels in the 
geothermal aquifer continued to decline. The Service believes that 
total well discharge has declined from a maximum of 61,526.7 
dam<SUP>3</SUP> (49,900 ac-ft) in 1981 to 42,785 dam<SUP>3</SUP> 
(34,700 ac-ft) in 1991, in large part due to area farmer participation 
in the CRP. The Service continues to support the CRP and the Natural 
Resources Conservation Service (NRCS) in its efforts to promote 
participation in the program. However, landowner participation in the 
program is voluntary. If present water management practices continue, 
or the CRP lands are returned to production, or when drier spring and 
summer climatic conditions return, all affecting pumping rates and 
duration, water levels in the aquifer will either continue to decline 
or eventually stabilize at a lower level resulting in the further loss 
of Bruneau Hot Springsnail habitat.
    In regards to the question of whether or not NRCS has consulted 
with the Service on the CRP, under section 7 of the Act, NRCS must make 
the determination whether the agency action is a ``major construction 
activity'' (50 CFR 402.12 (b)), and if so, the Federal agency must 
prepare a biological assessment of the action for listed species that 
occur in the action area (50 CFR 402.12 (j)). If the Federal agency 
determines that the action will likely adversely affect any listed 
species, the Federal agency must request formal consultation with the 
Service (50 CFR 402.12 (k)(1)).
    The CRP is administered by the Farm Services Agency (FSA) on the 
local level. The process for participation in the CRP is as follows: 
(1) an FSA representative completes an environmental benefits 
evaluation for the proposed CRP agreement, which includes an evaluation 
of the potential benefits to listed species; (2) if the proposal is 
accepted, an FSA representative develops a contract with the landowner; 
and (3) the FSA representative completes an environmental evaluation 
checklist, including an evaluation of any potential impacts to listed 
species. The determination for listed species is reviewed by NRCS for 
technical assistance and, at the option of NRCS, is sent to the Service 
for informal consultation. To the Service's knowledge, there has been 
no request for consultation from NRCS on the new CRP.
    Issue 10: A representative of the Southwestern Idaho Desert Racing 
Association stated that the use of off-road vehicles is not a threat to 
any sites occupied by the Bruneau Hot Springsnail. Therefore, no 
restrictions on off-road vehicle use should result from listing.
    Service Response: The Service agrees that off-road vehicle use may 
not currently pose a threat to habitat occupied by the Bruneau Hot 
Springsnail. Under section 7 of the Act, it is the responsibility of 
the BLM to determine whether these activities pose a threat to the 
Bruneau Hot Springsnail or its habitat (see also issue #9). The 
consultation process would be completed if the Service and the BLM 
agreed that there was no effect on the listed species.
    Issue 11: Some respondents believed that grazing does not currently

[[Page 32992]]

adversely impact the survival of the Bruneau Hot Springsnail or its 
habitat. In fact, grazing may actually improve habitat conditions by 
reducing overgrown vegetation that would otherwise render habitat 
unsuitable for the Bruneau Hot Springsnail.
    Service Response: The Service agrees that the maintenance of 
adequate fencing has served to reduce the direct impacts from livestock 
grazing on this species and its habitat in the Hot Creek drainage and 
along the west side of the Bruneau River. Livestock grazing on Federal 
lands within or adjacent to Bruneau Hot Springsnail habitats is 
authorized by the BLM and would be evaluated by the Service at the 
request of, and in consultation with, the BLM. The Service does 
believe, however, that the continued failure by Bruneau Hot 
Springsnails to return into the upper Hot Creek drainage is not limited 
by increased vegetative cover as a result of removal of livestock in 
the Hot Creek drainage. As already noted in the Background section of 
this notice, recruitment appears to be limited by the continued lack of 
adequate springflows, preferred substrate surfaces, weak migration 
abilities, and lack of an upstream colonization source.
    Issue 12: One comment expressed the concern that the Service did 
not provide the materials cited in the Federal Register notices of 
public comment periods outside of Boise.
    Service Response: The Service provided copies of all materials 
cited in the public comment period Federal Register notices upon 
request. The Service has opened three separate comment periods, with 
the first comment period beginning on September 12, 1995 and the fourth 
comment period ending on June 9, 1997, for a total of 218 days. Due to 
requests from several individuals, the Service sent copies of materials 
to 15 individuals or groups including, but not limited to: the Idaho 
Farm Bureau Federation; Scott Campbell, representing the Bruneau Valley 
Coalition; Fred Grant, representing Owyhee County; John Uriquidi; Ted 
Hoffman; and Frank Sherman, representing IDWR.
    Issue 13: Many respondents believe that the rights of private 
property owners will be violated as a result of restrictions associated 
with the listing of the Bruneau Hot Springsnail. The comments suggested 
that the Service should purchase private property considered essential 
to the Bruneau Hot Springsnail's survival, or should compensate 
landowners for not being able to fully utilize their property (e.g., 
through the loss of water rights or grazing leases). Additionally, a 
takings assessment should be prepared prior to any listing decision.
    Service Response: Issuance of this rule will not constitute a 
taking of private property. This rule does not make a determination 
about activities that may occur on private property.
    Issue 14: Some respondents indicated that the elevations of several 
springs (greater than 883.9 m (2,900 ft)) are higher than the Indian 
Bathtub spring elevation. They questioned the connection between these 
springs, the geothermal aquifer and water loss associated with the 
Indian Bathtub spring.
    Service Response: All thermal springs containing Bruneau Hot 
Springsnails along the Bruneau River, including the Indian Bathtub 
spring, arise from a single, regional geothermal aquifer. Spring 
discharges in the Bruneau Valley are related to the potentiometric 
levels (the imaginary surface representing a total head of ground water 
and defined by the level to which water will rise in a well) in the 
geothermal aquifer. As discussed by Berenbrock (1993), Pence Hot 
springs has a lower elevation (787.9 m (2,585 ft)) than the Indian 
Bathtub spring (814.7 m (2,672.9 ft)). Prior to 1966, discharge from 
the Indian Bathtub spring ranged from about 6,587.5 to 9,687.5 L/min 
(1,700 to 2,500 gal/min). After 1966, discharge from the Indian Bathtub 
spring began to decline to the point of its current flow, which 
essentially ceases seasonally. However, some springs with lower 
elevations (e.g., Pence Hot Spring), continued to flow at ``normal'' 
rates through September 1996. The reduction or loss of flow for springs 
at higher elevations reflects the lower potentiometric surface within 
the aquifer. Berenbrock (1993) found four cones of depression in the 
potentiometric surfaces for both the sedimentary and volcanic-rock 
aquifers, the largest of which occurs in the sedimentary aquifer and 
reflects a long-term water-level decline due to withdrawals. As the 
potentiometric surface continues to decline, springs with lower 
elevations will be affected in the same manner as Indian Bathtub 
spring. The continued lowering of the potentiometric surface may have 
resulted in the disappearance of additional springs since 1991. (see 
issue #1 and Factor A, ``Summary of Factors Affecting the Species'' for 
further discussion of the loss of springs.)
    The Service believes that the confusion regarding spring elevations 
stems from the spring surveys conducted by the BLM (Brunner, in litt. 
1994). The Service's understanding of the measurements in the BLM 
document, is that all the springs measured (12 in total) were between 
803.7 and 815.7 m (2636.09 and 2676.61 ft) with the Indian Bathtub 
spring at an elevation of 814.7 m (2672.89 ft). The measurements that 
are greater that these 12 springs were not actual springs but refer to 
reference and control sites used by the BLM for establishing the 
elevations of the springs (Brunner, in litt. 1994). Most of these 
higher ``elevation'' sites are located at the Bruneau River canyon rim 
(referred to as ``tie-in'' locations), or these sites represent a bench 
mark that was established as a control point to the tie-in locations. 
The elevation of the actual springs is within 1.2 m (4 ft) of Indian 
Bathtub spring. These springs are downstream of the Hot Creek 
confluence on the west side of the Bruneau River. Spring elevational 
measurements were taken at the initial point of spring discharge. 
Bruneau Hot Springsnails do not necessarily occur at that initial point 
but are usually found slightly lower on the rockface. This is due to 
tendency of the outflow to spread over the rockface, providing the 
wetted area necessary to create suitable habitat for Bruneau Hot 
Springsnail (see Background section for further details on habitat 
requirements).
    In summary, although recent information indicates a slight increase 
in water levels at 5 of 16 wells between 1994 and 1996, the total 
number of thermal springs and Bruneau Hot Springsnail occupied habitats 
has declined since 1991 along the Bruneau River. The most significant 
threat, ground water withdrawals, has not been addressed for the 
species. Opposing comments were based primarily upon concerns that 
listing of the Bruneau Hot Springsnail would affect the allocation of 
water and impact agricultural development in the Bruneau Valley. Some 
opposing comments questioned the adequacy of the Service's data. The 
Service has continued to gather information regarding the status of the 
species since publication of the listing rule in 1993. As discussed in 
the ``Summary of Factors Affecting the Species'' section, the Service 
concludes that all of the remaining populations of the Bruneau Hot 
Springsnail continue to be at risk.
    Issue 15: Commenters suggested that a National Environmental Policy 
Act (NEPA) analysis should be prepared prior to listing.
    Service Response: For the reasons cited in the NEPA section of this 
rule, the Service has determined that rules issued pursuant to section 
4(a) of the Act do not require the preparation of an

[[Page 32993]]

Environmental Assessment or Environmental Impact Statement.

Summary of Factors Affecting the Species

    After a thorough review and consideration of all information 
available, the Service has determined that the Bruneau Hot Springsnail 
should continue to be classified as an endangered species. Procedures 
found at section 4 of the Act (16 U.S.C. 1531 et seq.) and regulations 
(50 CFR part 424) promulgated to implement the listing provisions of 
the Act were followed. Under the Act, species may be determined to be 
endangered or threatened due to one or more of the five factors 
described in section 4(a)(1). This determination is based on the 
``Summary of Factors Affecting the Species'' and on comments received 
on the rule. These factors and their application to the Bruneau Hot 
Springsnail (Pyrgulopsis bruneauensis) are as follows:

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

    Agricultural-related ground water withdrawals threaten the 
continued existence of the Bruneau Hot Springsnail.
    Ground water withdrawal and pumping threaten the Bruneau Hot 
Springsnail through a reduction or loss of thermal spring habitats 
resulting from the decline of the geothermal aquifer that underlies 
Bruneau, Little, and Sugar Valleys in north-central Owyhee County, 
Idaho. Within the past 25 years, discharge from many of the thermal 
springs along Hot Creek and the Bruneau River has decreased or has been 
lost, thus further restricting the Bruneau Hot Springsnail habitats 
(Young et al. 1979; Berenbrock 1993; Mladenka and Minshall 1996).
    The Indian Bathtub area and Hot Creek represent the type locality 
of the Bruneau Hot Springsnail. By 1982, Taylor (1982) found that the 
Bruneau Hot Springsnail population in the Hot Creek/Indian Bathtub site 
had been significantly reduced by the reduction in spring discharge. 
Taylor (1982) noted that the core of the population occurred on 
vertical rock cliffs (rockface sites) protected from flash flood 
events. Varricchione and Minshall (1997) also found that ``The rockface 
sites are probably more suitable for Bruneau Hot Springsnail success . 
. .'' (page 50). Spring discharge in 1964 was approximately 9,300 L/min 
(2,400 gal/min), had dropped to between 503.8 to 627.8 L/min (130 to 
162 gal/min) (Young et al. 1979), and by the summer of 1990 discharge 
was zero during the summer and early fall water withdrawal season 
(Berenbrock 1993). Taylor (1982) speculated that this reduction in 
rock-face seep flows would leave the species vulnerable to the 
occasional flash-flood events known to occur in the Hot Creek drainage. 
Today, water from the Indian Bathtub spring is below the ground surface 
and reemerges about 300 m (984.3 ft) below the bathtub area 
(Varricchione and Minshall 1997). Visible spring discharge at the 
Indian Bathtub continues to be seasonal and low, ranging from 0 to 11 
liters per second (0 to .39 cubic feet per second) and is intermittent 
in most years (Varricchione and Minshall 1997; Cowing, in litt. 1996). 
This loss of discharge translates into a 10 m (35 ft) decline in water 
levels in the aquifer feeding the Indian Bathtub spring (Berenbrock 
1993).
    Beginning in the late 1890's, when ground water development for 
domestic and agricultural purposes began in the area of the geothermal 
aquifer, an estimated 339,075 dam \3\ (275,000 ac-ft) of thermal water 
discharged from Indian Bathtub spring (Berenbrock 1993). Between 1982 
and 1991, only 1,726 dam \3\ (1,400 ac-ft) discharged from the spring 
(Berenbrock 1993). This decline in discharge from the Indian Bathtub 
spring was noted beginning in the mid-1960's and coincided with the 
accelerated increase in ground water withdrawal associated with a rapid 
increase in the amount of lands irrigated with ground water throughout 
the area. From the late 1890's through 1991, nearly 1,726,200 dam \3\ 
(1,400,000 ac-ft) of water was discharged from flowing and pumped wells 
completed in the geothermal system (Berenbrock 1993).
    According to Berenbrock (1993) the two most apparent effects of 
pumping stress are declines in hydraulic head and declines in spring 
discharge. Discharge fluctuations correspond with the pumping season; 
lower flows in the late spring to early fall and high flows during late 
fall to spring. Changes in discharge from thermal springs corresponds 
with changes in hydraulic head, which fluctuate seasonally and are 
substantially less during late summer than in the spring (Berenbrock 
1993).
    It should be noted that ground water withdrawals have generally 
declined over the past 15 to 20 years, primarily due to cropland 
retired from production through participation in the CRP (Berenbrock 
1993). In the last 2 years, the time periods of ground water use during 
the irrigation seasons have been shorter and occurred later in the 
spring due to increased precipitation in Bruneau area (Cowing, in litt. 
1996). However, water levels in the geothermal aquifer have continued 
to decline, with a possible slight increase in 5 of 16 wells at the 
completion of the 1995-1996 water withdrawal season (Cowing, in litt. 
1996), again, due primarily to increased precipitation in 1995-1996 in 
the Bruneau area and thus less need for ground water withdrawals. The 
Service is concerned that the number of withdrawals may again increase 
in the next few years as croplands will again enter production when the 
current 10-year CRP expires. As of June 9, 1997, there were 24 active 
CRPs (acreage total is 6,880) in the Bruneau area, 13 of which are due 
to expire in October 1997 (acreage total is 5,500), 8 will expire in 
October 1998 (acreage total is approximately 1,000 acres) and the 
remaining CRPs will expire in October 1999 (Ron Abbott, Farm Service 
Agency (FSA), in litt. 1997). There are approximately 15,822 acres in 
CRP for all of Owyhee County. (See Factor D for further discussion of 
the CRP.) If present water management practices continue, or if the CRP 
lands are returned to production, or when drier spring and summer 
climatic conditions return, all of which affect pumping rates and 
duration, water levels in the aquifer will either continue to decline 
or will eventually stabilize at a lower level, resulting in the further 
loss of Bruneau Hot Springsnail habitat.
    While the decline/loss in springflows at Indian Bathtub spring and 
several other springs has been documented, springflow data has not been 
collected in all the remaining 116 springs containing Bruneau Hot 
Springsnails. Mladenka (1992) believes that prior to the recent decline 
in water levels in the aquifer and resultant fragmentation of remaining 
populations, all of the springs and seeps supporting Bruneau Hot 
Springsnails were connected to allow the natural dispersal and transfer 
of individuals. The studies conducted by Mladenka (1992) and Mladenka 
and Minshall (1993, 1996) indicate a general decline in the total 
number of thermal springs along the Bruneau River, the number of 
springs occupied by Bruneau Hot Springsnails, and a general decline in 
densities of Bruneau Hot Springsnails (see Background section for 
further discussion). In 1993, Mladenka and Minshall found dead Bruneau 
Hot Springsnails at one previously occupied spring site where flows had 
recently diminished and nine spring sites showed noticeable reductions 
in discharge (Mladenka and Minshall 1993). The majority of Bruneau Hot 
Springsnail occupied thermal springs

[[Page 32994]]

are located upstream of the confluence of Hot Creek to the Bruneau 
River (Mladenka and Minshall 1996). Since 1991, the total number of 
thermal springs in the referenced section of the Bruneau River has 
decreased by approximately 5 percent, the number of springs occupied by 
Bruneau Hot Springsnails has decreased by 10 percent, and the total 
area occupied by Bruneau Hot Springsnails has decreased by 13 percent 
(Mladenka and Minshall 1996). Total site area (including all springs 
and seeps, occupied and unoccupied by Bruneau Hot Springsnails) 
increased by 4.3 percent from 1991 to 1996 (Mladenka and Minshall 
1996). Most of this increase occurred due to lower flows resulting in 
more surface exposure of a single thermal spring outflow area below 
Buckaroo Dam, which is downstream of the majority of occupied springs 
(Mladenka and Minshall 1996). Further analysis of the total spring 
surface area shows a 32 percent decrease in upper (above the confluence 
with Hot Creek) occupied springs versus a 41 percent increase in lower 
occupied springs (Mladenka and Minshall 1996). This corresponds to a 20 
percent decrease in the number of occupied sites upstream of the 
confluence of Hot Creek to the Bruneau River, a 17 percent decrease in 
the number of occupied sites at the confluence, and a 45 percent 
increase in the number of occupied sites downstream of the confluence 
(see Background section for further information). At this time there is 
no information available indicating how much lower water levels can 
continue to decline before all thermal springs along the Bruneau River 
are lost. As potentiometric surfaces in the geothermal aquifer continue 
to decline, additional spring discharges will be reduced or lost, 
resulting in the continued loss of Bruneau Hot Springsnail habitat.
    In the original 1993 listing it was indicated that impacts had 
occurred as a result of cattle grazing in Bruneau Hot Springsnail 
habitats, especially along Hot Creek. These impacts included trampled 
instream substrates and habitats causing direct Bruneau Hot Springsnail 
mortality and displacement. Cattle also browsed and removed riparian 
vegetation, allowing temperatures to reach levels affecting 
reproduction or to ultimately be lethal to the Bruneau Hot Springsnail. 
Additionally, livestock grazing in the adjacent watershed, combined 
with ongoing drought conditions, contributed to an increase in 
sedimentation in Hot Creek, which eliminated Bruneau Hot Springsnail 
seep/spring habitats for almost 150 m (492 ft) in the Indian Bathtub/
Hot Creek drainage.
    The BLM has controlled livestock grazing by installing fencing on 
the north end of Hot Creek drainage and the west side of the Bruneau 
River. The BLM also plans to install additional fencing along the east 
side of the Bruneau River. Both fencing projects, if properly 
maintained, will protect Bruneau Hot Springsnail habitat from the 
effects of livestock.
    The original 1993 listing stated that recreational access also 
impacts habitats of the Bruneau Hot Springsnail along the Bruneau 
River. For example, small dams are sometimes constructed to form 
thermal pools and improve conditions for bathing. Construction of these 
pools could impact Bruneau Hot Springsnails through habitat 
modification as rock substrates are moved, flow is altered and 
sediments are trapped. These pools can also alter and possibly destroy 
the madicolous habitats preferred by the Bruneau Hot Springsnail as 
pool water levels are raised. Most of the springs along the Bruneau 
River are inaccessible to bathers due to an abundance of poison ivy 
(Rhus radicans). One or two pools downstream of the confluence of Hot 
Creek are used by recreational bathers but Bruneau Hot Springsnails 
have not been verified in those locations. Therefore, recreational use 
of the thermal springs and outflows is not considered a significant 
threat.
    In summary, the cumulative effects of water withdrawal continue to 
threaten the increasingly fragmented populations of the Bruneau Hot 
Springsnail and their thermal habitats.

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

    There are no commercial uses for this species. In other listing 
actions, certain mollusc species have become vulnerable to illegal 
collection for scientific purposes. Because the distribution of the 
Bruneau Hot Springsnail is restricted and generally well known, 
collection could become a threat to Bruneau Hot Springsnails.

C. Disease or Predation

    There are no known diseases that affect Bruneau Hot Springsnails. 
Juvenile Bruneau Hot Springsnails (less than 0.7 mm) are vulnerable to 
a variety of predators (Mladenka 1992). Damselflies (Zygoptera) and 
dragonflies (Anisoptera) were observed feeding upon Bruneau Hot 
Springsnails in the wild. The presence of a large wild population of 
guppies in Hot Creek and several of the other small thermal springs 
downstream along the west bank of the Bruneau River is a potential 
threat to the Bruneau Hot Springsnail. Mladenka (1992) observed guppies 
feeding upon the species in the laboratory. In addition to guppies, a 
species of Tilapia has ascended into and reproduced in Hot Creek 
(Bowler 1992). The presence of this new potential ``exotic'' predator 
may constitute a threat to the Bruneau Hot Springsnail by restricting 
repopulation of the species into Hot Creek (Varricchione and Minshall 
1997) and at other thermal spring sites that may be available to the 
Bruneau Hot Springsnail and the exotic fish species. Both of these 
exotic fish species can migrate into the Bruneau River corridor, both 
upstream and downstream of Hot Creek, and to other spring outflows when 
temperatures in the Bruneau River are suitable (usually during the 
summer months). Movement of these exotic fish species into other 
thermal springs occupied by the Bruneau Hot Springsnail might affect 
their continued survival within individual spring sites.
    It should be noted that madicolous habitats support neither of 
these two exotic fishes or dragonflies, but do harbor numerous 
damselflies. During his study, Mladenka (1992) observed no birds 
preying on the Bruneau Hot Springsnails.
    In summary, the Service considers the presence of predatory exotic 
fish species in Hot Creek and the Bruneau River drainage a possible 
threat to the Bruneau Hot Springsnail, which should be studied further.

D. The Inadequacy of Existing Regulatory Mechanisms

    At least three State agencies could potentially assist in the 
protection of the Bruneau Hot Springsnail. The IDPR has authority under 
I. C. Section 18-3913, 1967, to protect only plants, with animals not 
given special protection on Idaho lands. The IDFG, under I. C. Section 
36-103, is mandated to preserve, protect, perpetuate, and manage all 
wildlife. However, these mandates do not extend protection to 
invertebrate species.
    The IDWR regulates water development in the Bruneau area. It is the 
policy of IDWR to regulate and conserve ground water resources from 
depletion or ``mining''. In Baker v. Ore-Ida Foods, Inc 95 Idaho 575, 
513 P.2d 627, 635 (1973), the Idaho Supreme Court held that ``Idaho's 
Ground Water Act clearly prohibits the withdrawal of ground water 
beyond the average rate of recharge.'' However, any conservation 
measures imposed by IDWR to manage ground water ``mining'' are only for 
the

[[Page 32995]]

purpose of fulfilling senior water rights and not for the protection of 
fish and wildlife. At present, there is no specific allocation of 
either surface or ground water in the Bruneau area for the protection 
and conservation of fish and wildlife. In 1982, the IDWR established 
the Bruneau-Grandview GWMA pursuant to provisions of I. C. Section 42-
233a ``* * * to identify the area as approaching the conditions of a 
critical ground water area'' (IDWR 1992). This GWMA designation has 
allowed the IDWR to continue to receive and hold without action 
applications for water permits until it can be demonstrated that the 
proposed withdrawal will not adversely impact other water rights in the 
GWMA. Due to the continued decline in water levels in the geothermal 
aquifer, no applications for agriculture withdrawal within the GWMA 
have been approved since 1982. Without recovery of water levels, IDWR 
does not anticipate modification of the GWMA designation any time soon. 
In any event, GWMA designations are intended only to maintain 
sufficient ground water to fulfill existing water rights and supply the 
needs of irrigation, and not for the protection and conservation of 
fish and wildlife.
    The Bruneau area is also located entirely within the area of an 
ongoing water rights adjudication (Snake River Basin Adjudication). A 
Director's Report, due to the court in 1994, was to clarify existing 
water rights and water uses and permit IDWR to eliminate water rights 
that are of record but are no longer utilized. The IDWR also believes 
the adjudication process will need to be completed prior to the 
development and implementation of ground water conservation measures on 
behalf of the Bruneau Hot Springsnail that may affect existing water 
rights and uses since ``without completing this adjudication process 
there is no effective way to determine the existence or validity of 
water rights to serve as the basis for delivery'' (IDWR 1992). As of 
June 9, 1997, the Director's report, filed with the court, has not 
included agricultural reports from the Bruneau area.
    In 1995, the State of Idaho authorized the creation and supervision 
of Water Management Districts (WMD) by IDWR (Idaho Code (I.C.) 42-705 
et. seq.). Among the activities to be performed by a qualified district 
hydrographer in a WMD is--the monitoring of ground water levels at 
ground water diversions before the pumping period begins and during the 
pumping period; and immediate reporting to the Director of the 
diversion of any water appearing to be diverted without a water right 
or in violation of a water right. To date, the Bruneau/Grandview area 
has not been designated as a WMD. The Service is aware of only one WMD 
that is to be developed for the State of Idaho--for the Eastern Snake 
River Plain.
    Under the Idaho Ground Water Act, IDWR also regulates the 
construction and maintenance of geothermal (I. C. Section 42-238(4)) 
and artesian (I. C. Sections 42-1601 and 42-1603) wells so that they 
operate to conserve ground water resources and prevent unnecessary flow 
and waste. The IDWR in 1990 identified several artesian wells in the 
Bruneau area ``* * * leaking water at land surface or potentially 
wasting water in the subsurface due to inappropriate well construction 
techniques'' (IDWR 1992). To date no action has been taken to have 
these leaking wells rehabilitated so that the aquifer pressures can be 
preserved or increased. In 1995, the Service had provided funding to 
IWRRI to research the problem of well leakage in the Bruneau Valley. As 
of June, 1997, only one landowner had volunteered to participate in the 
research. The results of the research by IWRRI have not yet been 
submitted to the Service.
    In summary, the IDWR has authority to control ground water and can 
limit the development of new wells in a critical ground water area, 
impose water conservation measures, and also require meters on existing 
wells. To date, no action has been taken by IDWR to regulate 
implementation of water conservation actions or metering and repair of 
wells. IDWR has stated that
``* * * the Director has no authority under State law to shut down 
prior vested water rights in order to protect an endangered species'' 
(IDWR 1992). Therefore, measures taken by IDWR have been inadequate for 
the protection and recovery of habitats for the Bruneau Hot 
Springsnail.
    The BLM manages the public lands containing Bruneau Hot 
Springsnails and their habitats along Hot Creek and the Bruneau River. 
The BLM issues permits for livestock grazing on these lands and grants 
authorizations that could lead to the drilling of new wells or 
increased ground water use on BLM lands. In the past, the BLM has shown 
an interest in conserving the species and has solicited input from the 
Service regarding impacts that may result from any proposed activities. 
As discussed in Factor A, the BLM has implemented fencing to protect 
Bruneau Hot Springsnail habitats from grazing impacts.
    The CRP is authorized under the Food Security Act of 1985, as 
amended, to implement a voluntary program that offers annual rental 
payments, incentive payments for certain activities, and cost-share 
assistance to establish approved cover on eligible cropland (U.S. 
Department of Agriculture (USDA) 1997). This program encourages farmers 
to plant long-term resource-conserving covers to improve soil, water, 
and wildlife resources. The duration of the contracts are between 10 
and 15 years (USDA 1997). As discussed in Factor A, all of the current 
lands in CRP will expire by 1999. It is unlikely that all those 
eligible for the new CRP agreements will participate due to a dramatic 
drop in the rental rates (from about $50 per acre to about $20 per 
acre) currently offered through the CRP (Abbott, in litt. 1997). Area 
landowners have indicated that this drop in rental fees will not 
provide the necessary incentive to continue participating with the CRP.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    Sedimentation of Bruneau Hot Springsnail habitats is a threat to 
this species. Summer floods and mudflows during 1991 and 1992 delivered 
significant amounts of sand, silt and gravel to upper Hot Creek, and as 
of July 1992, completely filling the Indian Bathtub with at least 1 m 
(3 ft) of sediment (Robinson, et al., 1992). Following sediment 
delivery from a flash flood in October 1992, additional springflows 
have been completely covered over and Bruneau Hot Springsnail habitat 
eliminated from approximately 150 m (492 ft) in upper Hot Creek below 
the Indian Bathtub. While flash floods probably occurred historically, 
the decreased flushing effects of declining springflows have resulted 
in the filling in of Bruneau Hot Springsnail habitats at the Indian 
Bathtub and upper Hot Creek. Sediment deposited by periodic flash 
floods cannot be flushed by the remaining weak and declining 
springflows. Measures which could protect Bruneau Hot Springsnail 
spring/seep habitats in the Indian Bathtub and Hot Creek from the 
effects of flash flooding have not been implemented. These measures 
include the construction of small retention dams in the Hot Creek 
watershed to trap runoff sediment while maintaining thermal seep 
habitats. Therefore, sedimentation and flooding continue to threaten 
Bruneau Hot Springsnail habitat.

Determination

    The Service has carefully assessed the best scientific and 
commercial information available regarding the past, present, and 
future threats faced by the Bruneau Hot Springsnail. Based on this

[[Page 32996]]

evaluation, the preferred action is to retain the Bruneau Hot 
Springsnail as an endangered species. The species persists in only a 
few isolated thermal springs and seeps in Hot Creek and along an 8 km 
(5 mi) reach of the Bruneau River characterized by temperatures ranging 
from 15.7 to 35 deg. C (60.3 to 95 deg.). The free-flowing thermal 
spring and seep environments required by the Bruneau Hot Springsnail 
have been impacted by and are vulnerable to continued reduction from 
agricultural-related ground water withdrawal/pumping. The species and 
its habitat are also vulnerable to habitat modification from the 
effects of flash floods. The remaining complex of thermally related 
springs and their immediate outflows are not protected from the threats 
previously discussed. Existing regulations do not provide adequate 
protection to prevent further direct or indirect habitat losses. The 
Bruneau Hot Springsnail is in danger of extinction throughout all or a 
significant portion of its range, and therefore, fits the definition of 
endangered as defined in the Act.

National Environmental Policy Act

    The Fish and Wildlife Service has determined that an Environmental 
Assessment, as defined under the authority of the National 
Environmental Policy Act of 1969, need not be prepared in connection 
with regulations adopted pursuant to section 4(a) of the Endangered 
Species Act of 1973, as amended. A notice outlining the Service's 
reasons for this determination was published in the Federal Register on 
October 25, 1983 (48 FR 49244).

Author

    The primary author of this rule is Jeri Wood, Snake River Basin 
Office, U.S. Fish and Wildlife Service, 1387 S. Vinnell Way, Room 386, 
Boise, Idaho (208/378-5243).

Authority

    The authority for this action is the Endangered Species Act of 1973 
(16 U.S.C. 1531 et seq.).

    Dated: June 5, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 98-16099 Filed 6-16-98; 8:45 am]
BILLING CODE 4310-55-P