10

e. The bald eagle ( Haliaeetus leucocephalus), the only North American representative of the sea eagles (Grossman and Hamlet 1964), is restricted to North America. The breeding range formerly included most of the continent, but the species currently nests primarily in Alaska, Canada, the Pacific Northwest States, the Great Lakes States, Florida, and Chesapeake Bay. Winter range extends from Alaska, western Canada, and southern Nova Scotia south to the Caribbean and Mexico (American

Ornithologists Union 1957). Eagles were last; Qbservmd breeding in Nevada ic 1888 at eyramid Lake ( Linsdale 1936). Some wintering of eagles occurs in Nevada, primarily in the western portion of the State.

Decline of bald eagles throughout their range has been positively linked to reproductive failure due to organo-chlorine pesticides. Other mortality causes include shooting, lead poisoning from feeding on contaminated waterfowl, electrocution by power lines, and habitat destruction. Since DDT and other organo-chlorines were banned in the early 1970's, eagle reproduction seems to have improved. Currently, the greatest-threat to bald eagles is destruction of habitat from land development, logging, mineral exploration, and other human activities ( U.S.Fish and Wildlife Service 1982).

The Newland* Project area includes the Stillwater Wildlife Management Area ( Stillwater), a known wintering area for bald eagles. Wetlands in Stillwater are supported by water from several sources, including seepage from unlined canals, oxcess irrigation returns, and spills from Lahontan Reservoir. Wintering eagles at Stillwater prey upon fish and waterfowl. Mid-winter eagle counts from 1954 to 1984 indicate that the number of eagles using the area varied considerably from year-to- year but averaged 5 to 15 birds. During the winters of 1986 and 1987, 35 to 40 bald eagles were present on the refuge. Based on mid-winter counts, the number of eagles can not be directly

correlated with the amount of water reaching StillWetter in eny given yonr ( P=r•ueal Comments, Steve Thompson, Wildlife Biologist, Stillwater, August 1986).

Analysis of Impacts

The Service calculates that the draft preferred alternative Procedures would result in an annual average wetland loss of 7,000 to 9,000 acres (Navarre 1987). Of this total, 5,815 acres would be on Stillwater. Concurrently, water quality would be degraded in remaining wetlands. All losses of wetlands would adversely impact migratory bird and forage fish populations. In turn, this could also negatively affect bald eagle numbers and/or usage at Stillwater. Procedures may have some detrimental SigliellialegialeadatiftlatalaggatiNSWIAMIlailliEMMDMINO*01*Mlw1111011110ago 1411`3517■41.70.4......

11

effects on overwintering eagles during some years, but individual eagles would be expected to disperse to other areas. No known bald eagle nesting occurs anywhere in Nevada, and even the complete loss of overwintering bald eagle use at Stillwater would not jeopardize the species as a whole.

Effects of the Newlands Project, and possible Procedures, on the endangered cui-ui were analyzed as follows:

1. Use of Reclamation's Truckee-Carson Hydrologic Model to calculate hypothetical monthly flows in the Truckee River system which would have occurred during each year from 1901 to 1980 (80- yesr period of r000rd) under each ur the eight diversion criteria. The model also computes 80-year annual averages for such parameters as Pyramid Lake inflow, shortages to the Carson Division of the Newlends Project, and spills at Lahontan Dba.

2. Incorporation of a Cui-ui Index Subroutine into the model to compare the relative impacts of different water management plans on the species. The subroutine combines actual historic hydrologic data with known and attributed biological characteristics and population dynamics of cui-ui to calculate the response of a hypothetical cui-ui population.

The Cui-ui Index Subroutine tracks the reproductive response of a hypothetical cui-ui population to changes in environmental conditions over time. It is the latest of many attempts over the past 3 years to quantify the impacts of various water management plans on the survival of the species. The version used in this analysis is based upon the Habitat Evaluation Subroutine included in the 1986 draft Environmental Impact Statement for the Newlands Project Operating Criteria and Procedures which utilized prescribed lower Truckee River inflow to Pyramid Lake as the sole parameter affecting cui-ui reproduction. The new version is more sensitive to hydrologic variability because it uses a greater array of biological and physical information. It calculates the number of swim-up larvae recruited to the population each year (i.e., new year class) and the number of individuals remaining in each year class by incorporating the following parameters: river access, attraction flows, instream flow/temperature relation, fecundity rates, egg viability, temperature tolerance of eggs and larvae, annual mortality rates, and population size. Because of the numerous assumptions used in the subroutine the population projections should not be considered as absolute. The calculated number, however, can be used as a comparative index to compare the relative impact of various Procedures. Even if the values used in some of the assumptions were to change, the relative impacts of the different Procedures on cui-ui would be similar and would not affect conclusions.

The subroutine is initiated with a known number of male and female cui-ui in each year class. For this analysis, we began 12 the subroutine with the number of estimated to be present in the summer of 1987 so that the simulated impacts on the population would reflect current conditions. The elevation of Pyramid Lake, established at the 1987 level of 3,814 feet mean sea level, was adjusted annually for inflow and evaporation. The 1987 Stampede Reservoir storage of 90,000 acre-feet was also incorporated at initiation of the subroutine.

The occurrence and size of a spawning run depend upon the total inflow to Pyramid Lake from January through April (attraction flow), Z.he number of adults in the population, and lake elevation at the beginning of May. The relation of these variables to one another is based on observations at Marble Bluff Fish Facility from 1980 through 1987 and an estimate of the adult population during these years. These data indicated a curvilinear relation between the percent of the adult female population entering the spawning run and total inflow from January through April. The percentage also depends upon the passage avenue available. For example, if Pyramid Lake's elevation is below 3,812 feet mean see level bei above 3,783 feet mean sea level, passage is only available through the Pyramid Lake Fishway. At these elevations, less than 0.1 percent of the population would enter the fishway with total inflow of 51,000 acre-feet, 1.2 percent at 176,000 acre-feet, and 4.6 percent from 349,000 to_676,000 acre-feet. When the lake's elevation exceeds 3,811 feet mean sea level, passage is usually available over the delta and the spawning run percentages increase. With a total inflow of 60,000 acre-feet, 4.7 percent of the adult female population enter the spawning run, while 12.0 percent enter at 491,000 acre-feet, and 23.9 percent at 716,000 acre-feet. No spawning runs are predicted below these low elevations and inflows. There is no minimum number of adults required to initiate the run. The number of males and females in each year class, including the new year class, are reduced by natural mortality each year.

Females of prime reproductive age (7 to 30 years) are represented proportionately in the annwning run. For oxample, if lAttetmAiiiii voluwe and lake elevation indicate that 6.0 percent of the adult female population would enter the run, then 6.0 percent of the females in each prime reproductive age class are assumed to enter the run. Percentages are reduced for older than prime reproductive age. Because Pyramid Lake Fishway and the river trap at Marble Bluff Fish Facility have restricted passage capacities, the maximum run size was limited to 30,000 through the fishway or 150,000 through the river trap Run ciao in then reduced by 12.6 percent, based on studies which indicate that some fish are swept over the Marble Bluff Dam spillway before spawning.

The total number of eggs deposited is estimated by multiplying the number of female spawners by the average fecundity rate for their respective ages and then reducing the total by 10 percent 13 for egg retention. The number of swim-up larvae produced by these eggs depends upon the age of the female (i.e., egg viability), water temperature during incubation, and variability of instream flow.

The historic cui-ui population in Pyramid Lake may have numbered in the millions (Snyder 1917; La Rivers 1962). The adult female cui-ui population is now approximately 50,000 to 75,000 individuals which consists mostly of old females from the 1969 year class. The fate of the cui-ui depends on their reproductive success in recent years and the future availability of water. The status of the population is directly tied to the spawning runs which have occurred since 1980. If year classes fail to develop or prove to be relatively small, the population would be expected to decrease drastically in the next few years as the 1969 year class gradually ages and dies. However, if the year classes are relatively strong, the population will be more secure.

For the 80-year period of hydrologic record, the alternative diversions you have suggested result in 14 possible combinations of allowable diversions (7) and diversion criteria (2) are possible (Table 2). For any given allowable diversion, Criteria H always:

1. maintains a higher average Pyramid Lake inflow and elevation;

2. diverts significantly less water from the Truckee River;

3. noticeably reduces spills at Lahontan Reservoir; and

4. slightly increases shortages to the Carson Division.

Similarly, for criteria C or E thv following relationohips alwayu v1/4; vur as the atiowable diversion decreases (see Table 2):

1. Pyramid Lake inflow and elevation increase rapidly.

2. Diversions from the Truckee River decrease rapidly.

3. Lahontan Reservoir spills increase slightly.

4. Carson Division shortages decrease.

The reduction in shortages under criteria C always occurs in conjunction with a relatively large increase in pills at Lahonten Reservoir. For example, at an allowable diversion of 320,000 acre-feet, a 1,250 acre-feet smaller head gate shortage under criteria C occurs at the expense of an increase in Lahontan Reservoir spills of 6,800 acre-feet. In other words, five times as much water is spilled (wasted, in terms of benefit to cui-ui) 14 as is saved for the benefit of irrigators. Similar, or greater, ratios occur at other allowable diversions. Differences in shortages of only two or three thousand acre-feet represent less than 1 percent of total Newlands Project allowable diversions. Such quantities are undetectable with monitoring facilities currently in use which are only 86 to 90 percent accurate.

Hydrologic data are available and were utilized for the Truckee/Carson systems from 1901 through 1980. However, different hydrologic periods may be selected for analysis. Three such periods were selected to represent wet/dry extremes, and a moderate period containing no prolonged drought or wet periods. The period 1901 through 1917 was one of high runoff, whereas 1925 through 1937 was one of severe drought. From 1940 through 1980, no prolonged droughts nr wet periods occurred, but numerous smaller oscillations occurred which represent a more moderate period of record. For any hydrologic period of analysis, however, the foregoing basic relationships between allowable diversions and criteria C and B hold true (Table 2).

The hydrologic period of analysis greatly affects the cui-ui index (Table 3). Under a "wet" scenario (1901 through 17/1940 through 80) the first 17 years of exceedingly high runoff are followed by conditions of the 1940 through 1980 period and the cui-ui index under either criteria H or C at all allowable diversions would be very high. Conversely, a "drought" scenario (1918 through 80) omits the high runoff years, but includes the very dry years in the 1930's, and then follows with conditions in the 1940 through 1980 period. Under this scenario, the cui-ui index reached such low numbers under either criteria 13 or C at all allowable diversions that extinction would be assured. The 80-year period of analysis (1901 through 80) includes both the prolonged drought of the 1930's and the prolonged wet period during the first 17 years of hydrologic records. In contrast, the 40-yeal period from 1940 through 80 does not include any such extreme periods, but does include a number of shorter term dry periods and wet periods. The Service believes that this moderate hydrologic regime avoids extremes of "drought" or "wet" scenarios and represent reasonable approach to comparing effects on the cui-ui index of various possible allowable diversions and diversion criteria. The model indicates that under a "wet" scenario, long-term cui-ui survival will occur under any allowable diversion and/or diversion criteria whereas cui-ui survival is in jeopardy under any combination of criteria or diversion amounts under a "drought" scenario.

Under all hydrologic scenarios analyzed, the cui-ui index with Criteria B is higher than with C at all allowable diversions ( Table 3). Under the 40-year analysis period (expanded to 80 years to be comparablt to the entire period of record; indicaLcd as "X2" in Table 3), Criteria 13 would increase the cui-ui index by 16,039 at 320,000 acre-feet of diversion. While the relative 18 differences between Criteria C and E increase dramatically at higher diversions, the important factor for cui-ui is maintenance of a high absolute index (i.e., a high number of female cui-ui in the pnpnlation).

For each hydrologic period of analysis, a hypothetical baseline cui-ui index was computed which would have resulted if no diversions from the Truckee River to the Newlands Project had occurred (Table 4). This base index represents the highest cui- ui index which could hypothetically be reached under each hydralegiL 's cenario. The index for each allowable diversion and both Criteria E and C was then compared to the base and expressed as a percent of the base for the 1901 through 1980 and 1940 through 1980 (X2) analyses. This comparison shows that the relative percent gain is much higher as diversions are reduced at the upper end of the scale than at lower diversion amounts. This "return on investment" becomes noticeably less at a 320,000 acre- foot allowable diversion. Similarly, percent gain in the population index can be calculated as the allowable diversion decreases. As in the comparison with pev . L-of-base index, the percent gain in index is much higher for pair-wise comparisons above 320,000 acre-feet than below this figure. As an example, a 40,000 acre-foot decrease in allowable diversion (1940-1980/X2) from 360,000 acre-feet to 320,000 acre-feet results in a 204 percent increase in the cui-ui index, whereas a reduction from 320,000 acre-feet to 280,000 acre-feet results in a 32 percent increase. The index for 280,000 acre-feet was not modeled, but was interpolated manually). Thus, the 320,000 acre-foot allowable diversion represents the point below which additional benefits to the cui-ui index begin to decrease markedly in relation to additional reductions in the allowable diversion.

Given the current female cui-ui population of 60,000-75,000 and the 1940 through 80(X2) hydrologic scenario, only criteria E at an allowable diversion of 320,000 acre-feet or less would maintain or come close to maintaining, this index. Therefore, the Service expects that under this reasonable (=moderate) expectation of hydrologic conditions for the next 80 years, the cui-ui would survive as a species in Pyramid Lake and the lower Truckee River.

Stampede Reservoir, located on the Little Truckee River approximately 36 miles upstream from Derby Dam, is also a factor in divereion criteria selection and eperatluu. A 1982 U.S. Distliel Court decision (upheld by the Ninth Circuit Court of Appeals; U.S. Supreme Court declined to review) allocated Stampede Reservoir storage exclusively for conservation and management of threatened and endangered fishes in the Truckee River and Pyramid Lake. Consequently, Stampede water is available to augment Truckee River flows for the benefit of cui- ui and Lahontan cutthroat trout. Typically, water is released 16 during May and June, critical months for egg incubation and larvae out-migration, according to selection rriteris bscod on demiced water temperature (e.g., 63 degrees Fahrenheit in May) and to maintain consistent flows to prevent dewatering of spawning gravels.

A crediting system for Stampede Reservoir storage is possible under any diversion criteria. Such a system allows the District to receive storage credit in Stampede Reservoir in exchange for project water allowed to continue downstream of Derby Dam instead of being diverted to Lahontan Reservoir. Stampede crediting provides additional water in the lower Truckee River to benefit cui-ui in the early sprAng (spewning months) whila .1111 providing the Newlands Project with its total allowable diversion via releases from Stampede Reservoir for irrigation during late summer. Stampede credit is an overall benefit to the system because it improves operation of Lahontan Reservoir by reducing spills and precautionary drawdowns, and reduces evaporation losses because Stampede evaporation rates are lower than those for Lahontan Reservoir. The preferred alternative Procedures have not been analyzed by the computer model factoring in Stampede credit, but the Service believes that such credit would benefit cui-ui by increasing water supplies in the lower Truckee River under any Procedures scenario.

In our most recent Biological Opinion on 1987 Interim Procedures we concluded that continuation of annual Interim Procedures may well be inadequate to provide for the survival of the cui-ui ( Service 1987). We consider the preferred alternative long-term Procedures to be superior to previous long-term and annual Interim Procedures we have evaluated to date.

Cumulative Effekts

The only such program which may conceivably have an effect is the approval by the State of Nevada (State Engineer) of applications for pending water rights transfers. These applications request that water rights for lands taken from agriculture by municipal development be transferred to agricultural lands not presently certified for use of Newlands Project water. Under the presently proposed draft Procedures, however, such approval should have no effect on listed species because the maximum annual project limit on allowable diversion will he fived at 320,000 aetc-feli by Most, if not all, of the water-right transfer lands are already included in calculations which enable the allowable diversion to be lowered to the 320,000 acre-foot figure. .0906I'LDRE.EN

17

Incidental Tpke

Documentation of incidental take occurring under a proposed long- term water management plan such as is the subject of this consultation is not possible, even if any such take were to occur. We do not anticipate that any such incidental take of cui-ui. Thus, we have no measures to suggest that will minimize incidental take.

Conservation Recommendations

Conservation recommendations are provided to agencies as suggestions which, if implemented, will promote the conservation of listed species. Implementation of such measures is not required by the 1973 Endangered Species Act, as amended, and are, therefore, not legally binding:

1. Reclamation should consider buying water rights, including those proposed to be transferred between private lands, for transfer to the Federal government for use in conservation of listed species.

2. Reclamation should investigate the possibility of modifying the operation of Lake Tahoe Dam and the downstream Floriston Rates in the Truckee River to provide benefits to Pyramid Lake and the lower Truckee River.

3. Reclamation should provide ASSISTANCE to the Fish and Wildlife Service to resolve cui-ui passage problems at Marble Bluff Dam and Pyramid Lake Fishway.

4. Affected pertiea (Service, Roolomatien, DiftlLict, Department of the Interior) should cooperate to assess the water requirements orthe Stillwater Wildlifo MANTRGEWENI —Area, as well as the sources of water for the area. Efforts should then be made to relate this information to overwintering bald eagle usage of the area to determine if any quantifiable relationship exists. Possible effects of Procedures on bald onglen might then be Fltsdicted with greater accuracy.

This concludes formal Section 7 consultation regarding the preferred long-term Procedures for °pared—ions of the Newlands ProjekA. If the long-term Procedures are violated and enforcement actions prove ineffective, then we will expect reinitiation of this consultation. Similarly, should the limit on diversions for any year be proposed to be increased due to recalculation of the Procedures, we would expect reinitiation. 18

Questions regarding this consultation and Biological Opinion should be directed to Dr. Randy M. McNatt in the Great Basin Complex office, Reno, Nevada.

Attachments

. ogler toiwAIMPAIMMIPIMOMPINNIMIP"M"1"1"1111.114114.1111. P. 19

TABLE 1 Newlands Project Water Use and Irrigated Acres from 1967-1987

Gross Diversion Irrigated Year ( Acre-Feet) Acres 1/

1967 426,826 59,530 1968 394,553 61,697 1969 409,898 62,158 1970 417,830 62,350 1971 391,800 62,760 1972 384,677 60,765 1973 375,206 62,018 1974 402,181 60,661 1976 390,830 64,386 1976 267,946 64,043 1977 225,242 57,530 1978 362,890 64,388 1979 382,010 67,294 1980 341,544 67,034 1981 363,657 66,595 1982 323,839 66,487 1983 362,766 63,901 1f1R4 074,802 62,000 1985 379,700 63,100 1986 423,047 63,080 1987 350,316 2/ 61,713

21 Year Average 369,112 62,976

1/ Total irrigated acres as reported by Truckee-Carson Irrigation District, including acreage irrigated by ground water, acreage iub-irrigated, acreage irrigated with drain water, and non-water-righted acreage. Water-righted acreage for each year is substantially less than figures shown; i.e., 56,400 acres in 1985.

2/ Projected, based on year-to-date figures. r .

TABLE 2

Selected average annual parameters for 80-year (1901 through 1980) computer simulations of various combinations of NewlandA Project diversial eulteria C and and allowable diversions ( 1000's acre-feet)

Allowable Pyr.Lk Pyr.Lk C.Div Lah.Res. Truckee Canal Diversion Elev. Inflow Short Spills Diversion

288,000AF C 3825 436 .930 22.100 117.5 E 3831 452 2.740 14.160 99.5

300,000AF C 3821 428 .460 20.600 125.9 E 3828 444 1.090 13.100 107.6

320,000AF C 3815 414 1.230 18.200 140.4 5 3823 431 2.480 11.400 121.4

340,000AF C 3809 400 2.690 16.600 166.3 E 3817 419 4.170 9.700 134.3

360,000AF C 3802 386 4.360 14.700 170.5 5 3812 410 6.000 8.100 147.8

380,000AF C 3796 373 6.160 12.800 184.7 5 3806 394 7.960 6.800 162.0

400,000AF C 3789 360 8.160 10.700 198.1 5 3799 380 10.420 6.200 175.0 P.21

TABLE 3

Computer-simulated adult female cui-ui index at end of hydrologic period. () indicates base index for each period.

Hydrologic Period

Allowable Diversion 1901-80 1901-17/1940-80 1918-80 1940-80(x2) ( 104,066) (250,819) (21,211) (136,567)

280,000AF C 31,963 131,363 68 41,608 E 47,637 163,713 342 67,768**

300,000AF C 30,136 128,129 50 37,430 E 41,446 159,073 83 55,178**

320,000AF 14,060 122,182 23 32,122 37,377 147,839 58 48,083**

340,000AF C 5,071 116,144 0 9,881 E 22,956 134,682 24 33,332

360,000AF 365 99,796 0 2,671 7,430 122,846 14 15,830

380,000AF 317 93,535 0 175 ,373 114,346 0 4,525

400,000AF 308 87,210 0 85 462 105,912 0 626

** diversion criteria and amounts the Fish and Wildlife Service believes aro not likely to jeopardize cui-ui. See text discussion. P.22

TABLE 4

Cui-ui index expressed as percent of base index which would result if no diversion from the Truckee River occurred. A = 1901 through 1980; R a 1940-1000(hE)

Criteria E Criteria C Allowable Cui-ui % of Cui-ui % of Diversion Index Base Index Index Base Index

A. 400 452 .5 306 .3 380 3,373 9 317 .3 360 7,430 7 365 .4 340 22,956 22 5,071 5 320 37,377 36 14,060 14 300 41,445 40 30,136 29 288 47,537 46 31,963 31 0 (Base) 104,066 104,066

B. 400 646 .6 85 < .1 380 4,525 3 175 .1 360 15,830 12 2,571 2 340 37,332 27 9,881 8 320 48,083 35 32,123 23 900 55,170 40 37,430 27 288 57,768 42 41,508 30 0 (Base) 138,667 136,567