[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 (m2) (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
m2 (5338.9 to 4630.7 ft2)) (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 m2 (1
ft2) to 120 m2 (1291.9 ft2) in 1993
and from 0.02 m2 (0.22 ft2) 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 dam3 (49,900 ac-ft) to a low of 40,935.6
dam3 (33,200 ac-ft) in 1987 (1995 levels were 45,374.4
dam3 (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 dam3 (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 dam3 (10,100 ac-ft). Between 1978 and
1991 total well withdrawals were 673,218 dam3 (546,000 ac-
ft), averaging 51,786 dam3 (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 dam3 (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 dam3 (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 dam3 (45,800
to 33,200 ac-ft), with an average amount of 45,390 dam3
(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
dam3 (49,900 ac-ft) in 1981 to 42,785 dam3
(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
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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
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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