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002J28 The Bypass Drain now carries about 120,000 acre-feet per year of brackish water. . The salinity of the water in the Bypass Drain has decreased from 6,000 mg/l in the 1960's to 2,400 mg/l today because the saltiest Wellton-Mohawk ground water has been flushed from the aquifer by deep percolation of better quality irrigation return flows. If the Yuma Desalting Plant becomes operational using the currently installed technology, the flow in the Bypass Drain would be about 28,000 acre-feet per year of 7,500-mg/1 water. Operation of the Plant is not anticipated in the foreseeable future unless a serious drought develops. Therefore that contingency is not considered in this report; however, those parties evaluating longer-term solutions for the Delta must consider its impact on the Delta. (5) The Interim Surplus Criteria During the last five years, the availability of surplus water from high natural run-off has allowed deliveries of water to the lower basin states to increase from the "normal year' supply of 7,500,000 acre-feet per year to more than 8,300,000 acre-feet per year. The excess has been delivered primarily to California to meet its demands. With "normal" runoff conditions such as those expected in 2001, California would be legally required to reduce its water uses immediately to the maximum allowed to it under the law of the river. 'Ibis would require reductions amounting to as much as 800,000 acre-feet per year. In January 2001, the US Secretary of the Interior approved Interim Surplus Criteria (Isq allowing water users in the United States to exceed their normal year apportionment for a period of 15 years while conservation measures are implemented. 'Ibis is'to be accomplished through the Secretary defining and declaring a "surplus" condition, even though a flood control release is not necessary or imminent. Traditionally, the Colorado River system has been kept at maximum storage levels with releases strictly limited to downstream water delivery needs and flood control releases. The new ISC will allow for greater drawdown of Lakes Mead and Powell so that California can continue using water in excess of its normal apportionment until 2016. According to Reclamation's projections of demand and predicted weather conditions, the average amount of water stored in Lake Mead in 2016 ~ be 1.18 million acre-feet less than would be expected without the ISC. Under the Treaty, Mexico is entitled to an additional 200,000 acre-feet per year when water is available "...in excess of the amount necessary to supply uses in the United States..." 10 In the . past, however, Mexico has received and used additional water for agricultural, mmucipal, and industrial purposes when flood control releases occurred. Furthermore, surplus deliveries to Mexico improve water quality through'dilution. The ISC do not provide Mexico any surplus deliveries when an ISC surplus year is declared in the United States. Also, California's continued consumption in . excess of its normal year apportionment, allowed under the ISC, combined with the below normal runoff of 2000 (and likely 2001), reduces the likelihood of surplus water being delivered to Mexico in the next few years 11. With the ISC, in all but very high flow years those benefits will be lost. The Foreign Ministry of Mexico filed a formal diplomatic note on January 16, 2001, requesting that the State Department of the United States eliminate adverse impacts resulting from the ISC. Recent comments by Victor Uchtinger, Mexico's Minister of Environment, have emphasized the influence of serious border water issues on overall US/Mexico relations.12 The Delta issue is nqw being discussed at the highest levels of the two governments. At this point, 13 I I I I I I I I I I I I I I I I I I I