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0001;87 Fish and Wildlife Releases Historically, releases from Navajo Reservoir were made at a levels to satisfy the demands of the Navajo Indian Irrigation Project (See following discussion) and the other major irrigation and industrial water rights downstream on the main stem of the San Juan River. Early operational experience indicated that a release of approximately 500 cfs during the irrigation season, together with the inflows from the Animas River, was sufficient to satisfy all of the downstream demands, without shortage. Occasionally, it was necessary to release 600 - 700 cfs at times when the Animas River was unusually low. During the late winter and early spring months, the releases were increased as necessary to create flood control space for the anticipated runoff. . In recent years, as part of the Recovery Implementation Plan, the U.S. Fish and Wildlife Service (USFWS), in concert with the USBR and other water users on the San Juan River, has been re-evaluating the release patterns from the reservoir. One alternative being considered involves an increased flow release during the spring runoff months to more closely replicate the historic runoff hydrograph. To support this higher spring release, it is also necessary to reduce the normal release during the non-irrigation season in the fall and winter months, typically from the historic practice of 500 cfs :l: to about 250 - 300 cfs. This evaluation is on'going and no specific alterations of the historic release pattern have yet been approved by all parties. For purposes of the CROSS WRPM, it is recommended that the reservoir operation include a minimum release of 500 cfs during the irrigation season and the winter months. The release should be set up as a variable to accommodate future release rates that may evolve from the Recovery Implementation Plan. Navajo Indian Irrigation Project (NIIPI In addition to flood control, recreation and fishery benefits, Navajo Reservoir is operated primarily to provide water to the NIIP, an extensive irrigation project constructed by the USBR and administered by the Navajo Agricultural Products Industry (NAPI). The NIIP was authorized in 1962 to provide full service irrigation to approximately 110,630 acres of land owned by the Navajo Nation in northwest New Mexico on the south side of the San Juan River, generally between Kutz Canyon and the Chaco River. Construction of the NIIP began in 1973 and the first irrigation deliveries were made in 1976. The project is constructed in "blocks" of approximately 8,000 to 10,000 acres, developed as congressional appropriations are available. As of 1995, Blocks 1 - 7 are operational and are receiving irrigation water. Blocks 1 - 7 contain an estimated 63.450 acres of irrigable land. The Gallegos Pumping Plant which is currently under construction, will enable additional deliveries of irrigation water to higher elevation ground in Blocks 8 - 11, which constitute the remainder of the irrigated land. Diversions for the NIIP are made directly from Navajo Reservoir through a headworks operated by the NAPI. At full development, the average diversions from the reservoir are expected to range from 360,000 to 385,000 acre-feet per year (3.25 to 3.50 acre-feet/acrel. During the CROSS study period, the historic diversions to the NIIP, recorded by the USBR, ranged from approximately 33.463 acre,feet in water year 1976 to about 150,930 acre-feet for water year 1991. These historic monthly deliveries are incorporated in the CROSS WRPM. For future modeling scenarios, at full development of the NIIP, the following monthly diversions from Navajo Reservoir are included, based on recommendations of the USBR: 22