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, onnag~ 8 WATER SUPPLY FOR THE SAN JUAN-.CHAMA PROJECT Navajo ,:Reservoir will have a total storage capacity of 1,700,000 acre-feet, of 'which 672,000 acre-feet will be dead storage below the contemplated diversion level of the main canal of the Navajo Indian irrigation project. The live storage capacity for the regulation of the streamflows will be 1,028,000 acre-feet initially. Future sediment deposition is expected to reduce the live storage capacity to 960,000 acre-feet. Bureau oj Reclamation. studies . The Bureau's hydrologic studies of the San Juan Basin indicate that, with the storage for regulation available in the Navajo Reser- voir, water will be available to meet the demands for the initial stage of the San JuancChama project and the Navajo Indian irrigation project with no shortages. The study indicates spills from the reservoir averaging 215,000 acre-feet annually, which are an indication of the amount of water available for future use. The operation study supporting the Bureau's conclusions . was furnished the committee. The study has been brought up to date an!! covers the period 1928-60. It shows an average depleted flow at Blanco near the Navajo Reservoir of 899,700 acre"feet annually after allowing for future upstream depletion by the full development of the Pine River project in Colorado, the authorized Weminuche Pass diversion in Colorado, and bypasses at damsite to meet present uses along the San Juan Reservoir between Navajo Dam and Farm- ington. The study indicates demands for the initial phase of the San Juan-Chama project averaging 104,700 acre-feet annually, for the Navajo Indian irrIgation project averaging 508,000 acre-feet annually, and for the Hammond project averaging 23,000 acre-feet annually. The amount for regulatory losses and for natural flow uses below Farmington, not supplied by return flows or by tributary inflow below the Navajo Dam, was estimated to be 20,000 acre-feet annually, and reservoir evaporation losses were estimated to average 38,400 acre-feet annually. As indicated earlier, with the above-listed demands on the reservoir, the spills averaged about 215,000 acre-feet annually for the 33-yearperiod of study. The demand for the San Juan-Chama project averaging 104,700 acre-feet is based upon the estimates of divertible flow during the period of study. The annual amounts range from a hi~h of 225,000 acre-feet to a low of 40,000 acre-feet. The long-time dIvertible flow average for the initial stage of the San Juan-Chama project is !lsti- mated to be 110,000 acre-feet annually. . The Bureau's study of the Animas-La Plata project indicates a need to divert the flow of the Animas River and its tributaries for the irri- gation of 84f500 acres, of which 64,300 acres would be in Colorado and 20,200 wou d be in New Mexico. The project would also furnish water for industrial and municipal purposes to Durango, Colo. The Bureau estimates the diversion requirements to be about 259,400 acre-feet with an annual depletion estimated to be 130,000 acre-feet, of which 95,900 acre"feet would be in Colorado and 34,100 acre-feet would be in New Mexico. Using the historic flow data tabulated above, and assuming bypass requirements of 28,000 acre-feet annually for downstream irrigation and for fishery purposes, the Bureau comes up with an annual surplus flow of 392,000 acre-feet for the 25-year period 1928-52 which would be available for meeting the Animas-.