188. Memorandum from McGhee to Woodward, March 71

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  • ARA—Mr. Woodward


  • S/S


  • M—George C. McGhee

The attached memorandum, “The Salt Water Problem of the Mexicali and San Luis Valleys,” describes a problem which has arisen in connection with our border treaty with Mexico of February 1944. I would appreciate it if you would advise me whether or not the problem of undue salinity of the water delivered has been called to the attention of the Department and has been considered by the United States Government. If not, would you take appropriate steps to consider whether or not this issue should be raised with the appropriate U.S. authorities.

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“The Salt Water Problem of the Mexicali and San Luis Valleys”

Under the Water Treaty between Mexico and the U.S. of February 1944, Mexico is guaranteed annually 1½ million acre-feet of Colorado River water—from all sources. In the past, the dissolved salt content of the water delivered to Mexico has averaged about 750 ppm (parts per million), and Mexicali and San Luis Valley farmers have built up their farming practices and procedures based on water of this quality.

The Water Treaty does not provide for a guarantee of water quality, but “custom and usage,” plus that of treaty administration in the “spirit of good will and friendly cooperation,” morally demand that water of usable quality be delivered, if it is available, and this has been done until fairly recently.

Recently, however, a sudden and abrupt change was made in the quality of the water delivered to Mexico, this change having been [Typeset Page 450] brought about by the pumping of drainage water or “waste” from the Wellton-Mohawk Area of Arizona into the Gila River. This drainage water, with 6,400 ppm or more of dissolved salts, flows down the Gila to the Colorado, commingles with Colorado River water and then flows on to Mexico. Please note the attached map showing location of the Wellton-Mohawk Area and its nearness to the Colorado River and to Mexico.

As a result of the above, Mexico is now receiving extremely poor quality water (with 3,500 ppm or more of dissolved salts)—water that is unsuitable for use on the “tight” soils of the Mexicali and San Luis Valleys.

In a 1953 report issued by the Arizona Underground Water Commission, an extract of same being attached, Nicholas A. Rose of Houston, William Guyton of Austin and R. J. Tipton of Denver, nationally known, reputable ground-water [Facsimile Page 3] geologists forecast the cause and the source of the difficulty resulting in the delivery of poor quality water to Mexico and, at the same time, they also forecast the solution to the difficulty.

The first forecast made by Messrs. Rose, Guyton and Tipton has now been proven to be fully correct (the necessity of drainage pumping in the Wellton-Mohawk Area), and it is reasonable to assume that their second forecast is both sound and logical—that drainage water pumped from drainage wells will improve, because of dilution with good quality Colorado River water used in the Wellton-Mohawk Area, until it becomes entirely suitable for irrigation purposes. When this second forecast comes about, as it undoubtedly will, the Mexicali-San Luis difficulty will come to an end.

In the meantime, however, some 400,000 acres or more of Mexicali-San Luis farmland is being injured and a very large number of owners unnecessarily penalized for the benefit of a limited number of owners of some 75,000 acres in the Wellton-Mohawk Area.

The Bureau of Reclamation of the U.S. Department of Interior, the agency responsible for the Wellton-Mohawk drainage pumping, may be within its legal rights in pumping drainage waste into the bed of the Gila River even if it knows that such “waste” will end up on Mexican farmland; however, it is morally wrong and it is not being a good neighbor by throwing its waste over its fence onto its neighbor’s property.

The Bureau of Reclamation had ample notice and warning of the forthcoming necessity of drainage pumping in the Wellton-Mohawk Area, and had it commenced the solution to this particular reclamation project some years ago, it could have been easily worked out to the best interests of all concerned. A reclamation problem is not solved by merely moving it from one location to another.

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If there is an urge and desire to do so, this problem and difficulty can still be solved without serious damage or injury to either party.

  1. Transmits memorandum entitled “The Salt Water Problem of the Mexicali and San Luis Valleys.” No classification marking. 4 pp. DOS, CF, 611.12322/3–762.