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",' " j) C \I.)" . .,..... w The Brownell Task Force and the Mexican Salinity Problem: A Narrative Chronology of Events Introduction Seventeen years ago this summer, in June 1974, President Nixon signed into law P.L. 93,.320, the Colo$do River Basin Salinity Control Act. Title I of the Act authorized the Federal Governm~et to take measures to eliminate the effects of brackish return flows (or drainja.ge) from the Welltbn-Mohawk irrigation project on water delivered to Mexico under a 1944 treaty allocating!thewaters of the Rio Grande, Tijuana, and Colorado Rivers between the U.S. andlts southern n,eighbor. At the heart of the Title I program was a 100 million gaUon-per-qay (mgd). desalting plant to be built at a site near Yuma, Arizona. The desalting plant was to be the solution tq a water quality dispute that had periodically troubled U.S.-Mexican relations since 1961. " ~ The Yumll Desalting Plant was to remove 90 percent of the dissolved salts from the return flows, by ~ process called reverse osmosis. This desalted water was then to be blended with the remaining idrainage to yield water of the quality guaranteed Mexico under a 1973 Minute to the original tr\laty, Minute No. 242. The estimated capital cost of the plant, along with other measures Called for in Title I, was estimated at slightly under $100 million at the time of authorization. '~ ~ :}, ,~ ,"II t ~1. 'r , CompletiOn of the plant is now thirteen years behind the original schedule. Its capital, cost hils risen to mprethan $400 million, and projected yearly operation and maintenance costs range from $10 million to $33.million. The blended waters to be delivered to Mexico may cost. as much as $$00 per acre-foot to produce. I Why did tjle Federal government choose such a costly-and risky-means to implement an intemation~ Ilgreement? To answer that question, We must look at the history of that decision-the people involved, their perspectives and limitations, the courses of action they believed were available, and the constraints under which they worked. But first, whafwas. the problem th~y were solving-or thought they were solving? ^_:L j ,;!: Emergence of the Salinity Issue The treaty tjlatguaranteed Mexico 1.5 million acre-feet of Colorado River water annually "froIIl any and alllsources" did not specify its salinity. The salinity of water used for irrigation water is often critical to agricultural productivity, as high concentrations of salt reduce crop yields and may preclude the growing of salt-sensitive crops such as tomatoes and lettuce. Because Mexico 1