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economy. Southern Nevada requires additional water to provide for its phenomenal population growth. Southern Utah needs water conservation and control facilities to overcome seasonal shortages of surface water. There is not enough water available to the region at economic cost to provide for an expansion of irrigated acreage, except on Indian reservations and limited areas having local water supplies available, such as the Moapa Valley Pumping and Dixie Projects. However, because of the importance of agriculture to the region, a major objective is to augment the water supplies to maintain irrigated agriculture as close as practicable to present levels. Many crops are grown in the Pacific Southwest that cannot be grown else-where in the Nation or do not have proper market relations. The greatest future water requirements of the region will be for municipal and industrial uses, caused by the Nation's fastest rate of population growth. Other important needs are for irrigation, power, and flood control. The development plans presented in this report further include water supplies for recreation and fish and wildlife to cultivate those cultural activities which are considered essential to the well-being of an expanding population. The region presently has an estimated total developed water supply of 13,160,000 acre-feet annually. This is 1,360,000 acre-feet less than the present demand of 14,520,000 acre-feet. Demand will increase to 17,015,000 acre-feet by 1975; 18,725,000 acre-feet by 1990; and 19,805,000 acre-feet by the year 2000. In the meantime, the flows of the Colorado River available to the lower basin will diminish steadily because of continuing development in the upper basin within its Compact entitlement. The California State Water Project will provide 1,900,000 acre-feet before the year 2000. The balance will have to come from improved water management and from new sources. The precepts under which the Department of the Interior has historically acted have never encouraged the development of one area to the detriment of another. The diminishing of an existing economy, or the retarded development of another, carries nationwide implications. In the Pacific Southwest, defined for the purposes of this study as portions of each of the above five States--each dependent to some extent on the Colorado River--it is incumbent upon the Secretary of the Interior in any plan of regional water development to preserve, protect, and promote the economy and interests of all the affected States. The water plan contained in this report meets these objectives. The Initial Plan proposes that the Congress guarantee, as a matter of Federal policy through construction of necessary works, 2Epson Perfection 4870 Photo, 400 dpi, 8 bit, 14,045,184 byte