Page 1

May 11, 1962 Memerandum To: The Secretary From: Science Adviser Subject: Joint Mexican-American Panel to Study Salinity Problems in the Lower Colorado River Basin The Joint Mexican-American Panel has now completed a preliminary draft of its report, and has submitted it to the international Water and Boundary Commission. The Commission has noted the report, and is forwarding it to the Departments of State and Interior for review before final agreement. A meeting was held yesterday (May 10) in Denver between Commissioner Friedkin and the representatives of the Governors of the seven Colorado River Basin States. I under stand that the Governor's representatives urged a delay of several months for more study before the United States Government agrees to a final report with recommendations for action. It is unlikely that Mexico will accept such a delay. Following is a summary of the work of the Panel and of its conclusions, as I understand them. The problem faced by the Panel was to find means to reduce the salt content (especially the sodium content) of the Colorado River water delivered to Mexico to a level where that water could be used for economically beneficial irrigation agriculture in the Mexicall Valley. This involved two questions: (1) Irrigation practices and drainage in the Mexicall Valley; and, (2) the high salt and sodium content of the drainage water from the Wellton-Mohawk project. Wellton-Mohawk drainage water, with a salinity of about 6,000 parts per million, has been discharged into the Colorado River at a rate of appreximately 300 cubic feet per 600 ?? second since September 1961. As a consequence, the salt content of the water delivered to Mexico at the northerly boundary has increased from less than 1,000 parts per million in prior years to about 2,600 parts per million in the winter of 1961-62.Epson Perfection 4870 Photo, 400 dpi, 8 bit, 1,299,623 byte