Chapter 1: Summary of "The Law of the River"

Home Browse Search

CHAPTER I 27 the Imperial Dam in the United States, which contribute to the drainage waters. Under this proposal average salinity would have been reduced to about 1,130 p/m in 1973. Mexico rejected this proposal because of the difference in quality between Colorado River water delivered to the United States water users at Imperial Dam and the quality of the waters delivered to Mexico. In the in- terim, Minute No. 218 was again continued. 0.2 Minute No. 241 Following meetings on June 15 and 16, 1972, between Presidents Nixon and Echeverria, Minute No. 241 of the International Boundary and Water Commission, dated July 14, 1972, replaced Minute No. 218. Minute No. 241 provided that the United States would discharge Wellton- Mohawk water below Morelos Dam at the annual rate of 118,000 acre -feet per year (amounting to 73,000 acre -feet during the balance of 1972) . In place thereof the United States would substitute an equal quantity of other waters, or an additional 41.000 acre -feet of water released from above Imperial Dam and 32,000 acre -feet of water pumped from 12 wells on the Yuma Mesa. The result was that the total deliveries exceeded the 1.5 million acre -feet per year guaranteed by the Treaty since the bypassed Wellton- Mohawk drainage waters were not counted as part of the Treaty water. This process reduced the average annual salinity of water delivered to Mexico from 1.242 p/m in 1971 to 1,141 p/m for the year ending June 30, 1972. Under Minute No. 241 Mexico further requested that the United States discharge the balance of Wellton - Mohawk drainage water (approximately 95,000 acre -feet) below Morelos Dam, for which no substitution of fresh water was to be made, and which was charged to Mexico's 1.5 maf deliveries. This resulted in a further decrease of the average salinity from 1,140 p/m to 980 p/m for the year ending June 30, 1973, which was about 130 p/m higher than the average salinity of water arriving at Imperial Dam for a similar period. 0.3 Minute No. 242 As promised in the June 1972 meetings by President Nixon, on August 16, 1972, he appointed Mr. Brownell as his special representative and later as a Special Ambassador and Minute No. 242, dated August 30. 1973, evolved. Ids principal '._provisions were_ : the United States would adopt measures to assure that Mexico received water with an average salinity of no more than 115 p /m, plus or minus 30 p /m, over the annual average salinity at Imperial Dam: the United States would bypass Wellton- Mohawk drainage water at the annual rate of 118,WO acre -feet per year without charge against Mexico's Treaty allotment, and substitute therefor an equal volume of other waters to be discharged to the Colorado River above Morelos Dam; the United States will continue to deliver approximately 140,000 acre -feet per year on the land boundary at San Luis Mexico, in partial satisfaction of the Treaty obligation; the existing Wellton- Mohawk drain would be extended approximately 53 miles to the Santa Clara Slough on the Gulf of Mexico at United States expense; ground -water pumping within 5 miles of the Arizona- Sonora boundary would be limited by each country to 160.000 acre -feet per year; the United States would support Mexican efforts to finance improvement of the Mexicali Valley; and the new Minute is the permanent and definitive solution to the salinity problem. The Mexican salinity problems are elaborated on in Chapter XIII. P. The Colorado River Basin Salinity Control Act The measures to be taken by the United States pursuant to Minute No. 242 included construction of a ma- jor desalting plant near Yuma, Arizona, to treat the bulk of the Wellton- Mohawk drainage water; lining or } construction of a new lined Coachella Canal in California to salvage approximately 132,000 acre -feet of water annually; reduction of the irrigable acreage in Wellton- Mohawk from 75,000 to 65,000 irrigable acres --- -- - and improved "efficiency in the District; and - construction - of a well field along the - southern border _of .the ....._____.