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27 ,I Activities Prior to Mav 7. 1990 Draft BioloQical Ooinion In attempting to identify reasonable and prudent alternatives to the proposed Project, the Service, in cooperation with Reclamation, examined several options during the formulation of the first draft biological opinion that WaS issued on May 7, 1990. Initially, the Service queried Reclamation as to existing flexibility within the Project features and/or potential design changes that would allow for operation of Project storage facilities to benefit Colorado squawfish in the San Juan River. Reclamation responded that there was not any Project flexibility and that, if they released water from storage, it would necessitate pumping additional water out of the Animas River to refii1 Project reservoirs. The use of the Navajo Dam and Reservoir was considered as a possible means of offsetting Project impacts since it is a Reclamation-operated facility and is situated on the San Juan River upstream of occupied habitat. Three options were considered: (1) the Service took the preliminary position that, because the Project would annually deplete 154,800 acre-feet of water from the San Juan River subbasin, Reclamation should provide that same amount of water back to the San Juan River via releases from the Navajo Dam; (2) Reclamation proposed an alternative to the Service position which would replace Project depletions, totaling 90,800 acre-feet of water in April, May, June, and July only. During the remaining 8 months of the year (August-March) Reclamation would not release water from the Navajo Dam to offset Project depletions; and (3) phasing Project depletion replacements consistent with the cDnstruction schedule. Because the Project would be constructed in phases (i.e., Phase 1: Ridges Basin Dam, Reservoi r, and associ ated conveyance facil it i es; and Phase 2: Southern Ute Dam, Reservoir, and associated conveyance facilities), an additional option considered was offsetting PrDject depletions associated with Phase 1 (approximately 111,200 to 138,300 acre-feet) which would be completed by the year 2000; and then use the results of continued biological studies which would be done concurrently with construction of Phase 1 to formulate any additional needs that may accrue as a result of Phase 2. As the biological and hydrological ramification of the three options were discussed, it was realized that none were biologically defensible. The Service believes that in most years the river regime is already at or below the threshold for minimum flows (particularly during the spring months) whereby the fish could survive and reproduce in the river. Any further depletions to the river system without a complete redistribution of the annual hydrograph could render the San Juan River unusable by the Colorado squawfish. Reproduction appears to be occurring only during years of high spring flows. Under current operation of the Navajo Dam and Reservoir, spring peaks are severely reduced in all but wet years, while summer and winter flows are substantially increased, Merely replacing the amount of water depleted as a result of the Project with water stored in the Navajo Reservoir still results in a net depletion in the San Juan River subbasin and would further reduce flows in the San Juan River commensurate with Project depletions, and, therefore, within occupied habitat for Colorado squawfish. Additional discussions continued; however, no solutions or additional alternatives were identified by the time the May 7, 1990, draft biological opinion was completed. :~; y~ .~ , :.'" ,', " , ,.~~ .,- r:t ~~ ~""" :-') if