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drainage water in the winter time because of (3) above, and thus reduce Arizona' allotment for consumptive use under the anticipated Supreme Court decision, (2) above. The proposal by the United States Panel that additional wells and a bypass channel be constructed would ultimately save water for U. S. uses, because if would result in removing the present salt water from the Wellton-Mohawk aquifer, and thus eventually allow the storage of drainage water. All Wellton-Mohawk return flows could then be pumped out during the summer months and credited to United States deliveries. But for a long time, this system would not meet Mexico's salt balance requirement unless there were a marked reduction in the water available for actual consumptive use in Arizona as opposed to the legal definition in the expected Supreme Court decision. Because of (3) above, the condition stated in Senator Hayden's letter of June 7, 1962, that "...all water delivered to Mexico be charged against Mexico's allotment under the Treaty" is clearly unrealistic. If this requirement is interpreted as being applicable only to the Wellton-Mohawk return flows; it precludes the possibility of installing a tile drainage system, even for the mesa lands where such drainage might be essential. In effect, this requirement says that all Wellton-Mohawk return flows must be delivered to the River during the summer months. This can be accomplished only by continuing the present pump drainage system, and constructing more wells and a larger conveyance channel. The salinity of the water delivered to Mexico during the summer months, will be very considerably above salt balance, and they can be expected to seek legal redress in the International Court of Justice. The work of the United States and Mexical scientific panels has been helpful in obtaining the facts and clarifying the issues bearing on this difficult problem. The studies to be undertaken by the Bureau of Reclamation will undoubtedly also be helpful. I have become convinced, however, that definitive steps toward a solution will require not only a broadly-based technology (including sophisticated ground water hydrology), but firm political statesmanship. The issues involved are applicable not only to the Colorado River, but also to the Rio Grande, the Columbia, and other rivers which cross our Canadian and Mexican boundaries. Perhaps Congressional and other representatives of the northwestern states and of Texas should be brought into the conversation. Roger RevelleEpson Perfection 4870 Photo, 400 dpi, 24 bit, 1,968,157 byte