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time, it appears that construction of additional drainage facilities in our District, including wells, tile drains, and conveyance channels, combined with a selective and controlled pumping program, will provide a workable solution which will most nearly meet the needs of both the United States and Mexico. Such a program obviously cannot be completed by the October 1963 date mentioned by the two Presidents, and in fact will require several years to place in full operation. During the interim period it is our opinion that an alternate course to cope with the immediate problem must be followed. As you are aware, much of the problem in the Mexicali Valley is related to its cropping pattern whereby most of the acreage is devoted to cotton, which requires large summer deliveries of water. As a result, only the minimum quantity of water is scheduled during the winter months for wheat and other miscellaneous crops. Normally the minimum flow in the winter months consists largely of drainage return flow, with no releases of stored water for dilution. Any reduction in the quantity of drainage return flow reaching the Colorado River during the winter months would tend to improve the quality of Colorado River water reaching Mexico during this same period. The problem in the Mexicali Valley also relates, among other things, to the lack of adequate drainage and the irrigation of too large an acreage for the amount of water available. In view of this situation, -2-Epson Perfection 4870 Photo, 400 dpi, 24 bit, 10,472,960 byte