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Phase 1 facilities by October 1963, a supplemental appropriation will be required no later than March 15, 1963. Total cost of Phase 1 is estimated to be $6,000,000. Phase 2 would consist of an additional 300 c. f. s. outlet drainage conveyance channel through the Wellton-Mohawk area, possibly some additional drain tile in selected areas, reconstruction of the existing Gila River pilot channe1, 12 new wells with appurtenant discharge facilities in the South Gila Valley, and slight modification of gates at Imperial Dam. A flood control channel with protective dikes through the length of the Wellton-Mohawk Irrigation and Drainage District has been authorized. One dike of such a channel would protect the proposed new 300 c. f. s. outlet channel and provide a common right-of-way for both purposes. From a cost, construction, and safety standpoint the flood control channel and protective dikes should be constructed ahead of the 300 c. f. s. drainage channel as a part of Phase 2. The Phase 2 program would prmit greater flexibility in selective pumping and summer regulatory pumping to conserve stored water. Phase 1 and 2 when combined (without increased cotton acreage) would reduce the peak salt concentrations in the water delivered to Mexico to about 1,800 p.p.m., while still maintaining satisfactory ground water conditions within the District. Reduced drainage pumping associated with increased cotton acreage, if combined with Phase 1 and 2, would further reduce the peak salinity. The estimated cost of Phase 2 construction is $30,000,000. Of this amount approximately $20,000,000 is for the flood control channel and dikes. Phase 3 involves total overall river regulation on the lower Colorado River, and would consist of integrating ground water pumping with the river regulation that will be provided by Senator Wash Regulatory Reservoir now under construction. As Phase 3 construction is not considered in providing relief during the winter of 1963-64 or 1964-65, it will not be outlined further in this memorandum report. The studies on which the above recommendations are made included: (1) periodic water sampling and analyses from selected locations on the Colorado River and on drains providing return flow to the river below Hoover Dam; (2) forty-nine 12-inch test wells drilled to a depth of 130 feet from which both water and soil samples were collected at varying depths to evaluate in detail the quantity, quality, and location of ground water underlying the Wellton-Mohawk Valley; (3) numerous shallow test borings in both the irrigated and noirrigated areas of the Wellton-Mohawk District from which soil and water samples were taken to evaluate the degree of land reclamtion accomplished and remaining to be accomplished; (4) a field study of soils in the Mexicali Valley, which was limited to one week, during which samples were collected from 20 type locations and subjected to detailed 3Epson Perfection 4870 Photo, 400 dpi, 8 bit, 1,877,371 byte