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., ; , '. . . - 3 - I. Current and Potential Iniurv to the Dolores River ISF Typically, the Unit is in priority one to two months a year, and the Unit's out-of-priority depletions have averaged about 240 acre-feet per year. The Division Engineer for Water Division 4 estimates that approximately 315 acre-feet of the 700 acre- feet released from McPhee Reservoir would reach the Unit to replace out-of-priority depletions. While the amount of augmentation water to be released appears to be sufficient to cover the Unit's annual out-of- priority depletions, the releases may not always match the timing of the Unit's depletions, which could injure the Dolores River (SF. Further, the potential exists for Reclamation to increase the operation of the Unit from 325 days a year to 365 days a year if the need to pump more brine ground water arises, which could result in additional out-of-priority depletions. It is important to note that currently, Reclamation does not intend to increase Unit operations, and the 700 acre- feet release will result in a minimal amount of injury that only will occur if the released water does not match the timing of the out-of-priority depletions. 2. Proposed Mitigation Under this proposal, the mitigation results from both the Unit operations and from the guaranteed annual release of 700 acre-feet of water from McPhee Reservoir. Unit operations have significantly benefited the natural environment of the Dolores River at and below the Unit. Prior to the initiation of the Unit's operation in 1990, the salinity levels in the Dolores River through Paradox Valley most often exceeded levels that aquatic life could tolerate. By 1996, about ninety per cent reduction of the brine inflow had been realized (313 tons per day to 29 tons per day). This reduction in total dissolved solids has allowed aquatic organisms to reinhabit the last seven miles of the Dolores River to its confluence with the San Miguel River. Further, due to reductions in salinity levels, the Dolores River through Paradox Valley is no longer a barrier to upstream migration for native fishes as it most often was prior to Unit operations. The guaranteed release of 700 acre-feet to Dolores River below McPhee Reservoir and the addition of water to the fishery pool will benefit the natural environment of the Dolores River by enhancing habitat conditions for the tail water trout fishery and the native fishery further downstream. The native fishes benefited include the flannelmouth sucker, bluehead sucker and the roundtail chub, all three of which have suffered serious population declines in recent years throughout the Colorado River Basin. In addition, riparian vegetation will also be benefited during the growing season by the slight increase in Dolores River water elevations. The additional released water will benefit the entire lSF reach of 125 miles, including the approximately seven-mile segment of the reach that could be injured by the Unit's depletions. Proposed Memorandum of Al!reement Staff has negotiated a proposed Memorandum of Agreement ("MOA") with Reclamation that is attached hereto. The MOA . describes the operations of the Unit . quantifies the past and potential future injury to the Dolores River ISF . describes the mitigation provided by the Unit and the 700 acre-feet of water to be released annually Flood Protection. Water Project Planning and Finance. Stream and Lake Protection Water Supply Protection. Conservation Planning