Laserfiche WebLink
<br />GOJ4:f7 <br />Summary of Water Resources in Northern Mexico . <br /> <br />Purpose <br />An ad hoc committee organized by representatives of the Seven U.S. States in the Colorado River <br />Basin has been convened to explore means by which to enhance water supplies available within <br />Mexico for environmental, municipal, industrial, and agricultural purposes without legal effect <br />upon the permanent water rights of U.S. states or users of water pursuant to U.S. or U.S. state law. <br />The purpose of this document is to. summarize the data and information related to the use of <br />Colorado River water in Mexico and identify data deficiencies that limit a complete understanding <br />of its use, the possible development of water budgets and exploration of means of enhancements of <br />water supplies. It is presumed that, if means of enhancement were developed to address <br />environmental demands, the Mexican government would ensure that those enhancements would not <br />be diverted to agricultural uses. <br /> <br />Discussion <br />Currently known actual data related to the identity and quantity of water resources, consumptive <br />uses, exports and flows supporting environmental resources in the Colorado River delta, Cienega de <br />Santa Clara and Salton Sea were studied with the object of evaluating whether a water budget for <br />Mexicali and San Luis Valleys, identifying those variables, was possible. However, there are too <br />few actual data series related to these variables. The following are observations related to current <br />data availability, quality, and usefulness with respect to compiling such a water budget: <br /> <br />U.S. (IBWC, USBR, USGS) <br />. Data from these sources are sufficiently current and comprehensive such that a temporal <br />analysis of the U.S. deliveries to Mexico and drainage water from the Wellton-Mohawk <br />Irrigation and Drainage District can be performed. <br /> <br />. Seepage from the All American Canal that is used by Mexico was estimated as 90% of the <br />measured loss between Pilot Knob and Drop 3 (90% of 84,500 acre-feet (AF), or approximately <br />76,000 acre-feet per year (AFY)). Others have used estimates of up to 100,000 AFY. <br /> <br />. Estimates of groundwater underflow from the U.S. to Mexico were taken from USBR LCRAS <br />reports (1995 to 2000). <br /> <br />Mexico (CILA, CNA, Rio Colorado Irrigation District, reference material) <br />Insufficient data is available to construct a meaningful water budget for Mexico for the purposes <br />described above. Available data is piecemeal and typically an estimate and/or a range of values. <br />Although some data is reported as an annual value, most of the data is without temporal scale, <br />making it exceedingly difficult to correlate U.S. deliveries with consumptive use and groundwater <br />production in Mexico. Some of the limitations are described below: <br /> <br />. With respect to the flows supporting the Colorado River delta, only an estimate can be made <br />based on the difference between the amount of water delivered at the Northern International <br />Boundary and the amount that was diverted at Morelos Dam, plus estimated agricultural <br />drainage from the Rio Hardy and Rio Pescaderos. There are no stream gages installed on the <br />River or the agricultural drains to substantiate any estimate of flow. <br /> <br />Page 1 of 10 <br /> <br />Seven Basin States June 1, 2002 <br />