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<br />January 7, 2004 22 <br />from the drain is less than one percent of the ground water flow in the area and is not significantly <br />affecting the quality of the ground water or the Colorado River water. All of Wellton-Mohawk's <br />drainage flows are expected to be contained in the MODE for CY 2003 and CY 2004. <br /> <br />Measures that are being taken to ensure that the salinity differential requirements at NIB will be met <br />include reducing drainage pumping in the South Gila Valley in areas with more than adequate depths <br />to groundwater; returning some drainage tlows from the Yuma Mesa Conduit to the Yuma Valley <br />Drainage System and thence to the boundary pumping plant at the Southerly International Boundary <br />with Mexico; ensuring that no drainage water from the MODE will be spilled to the Colorado River; <br />and reducing drainage pumping from the Yuma Mesa Well Field when necessary near areas with <br />acceptable depths to groundwater (generally wells YM 10-13). <br /> <br />Several Yuma Valley Drainage wells that used to discharge to the Southerly International Boundary <br />(SIB) have been connected to the Yuma Mesa Conduit. In addition, 6 Yuma County drainage wells <br />constructed in the late 1980's are now discharging to the Yuma Mesa Conduit, when formerly they <br />were operated only during flood or space building years, causing salinity levels at the NIB to <br />increase as the quantity of drainage inflow to the Colorado River above NIB increases. At the same <br />time, the quality of water arriving at Imperial Dam improved, even though the amount of water <br />released from Parker Dam has been reduced beginning in CY 2000. These issues combined together <br />are currently resulting in a forecasted salinity differential near the maximum allowed under Minute <br />242. <br /> <br />Located at the Yuma Desalting Plant is a research facility known as the Water Quality Improvement <br />Center (WQIC). The primary role of the WQIC is to find ways to reduce operating costs of the <br />YDP. To do this, Reclamation personnel who work in the WQIC investigate new technologies and <br />processes, and explore improvements in operational and maintenance efficiencies. The WQIC also <br />serves as a key component in Reclamation's Science and Technology program-hosting third party <br />research to enhance the spread of publicly-developed water treatment technology into private <br />industry. This program serves Reclamation in two ways: it reduces the overall cost of maintaining <br />the YDP by performing research for paying outside parties pursuing similar interests, and it helps <br />guarantee additional water supplies by supporting the proliferation of water-stretching treatment <br />technology throughout the U.S. In addition, the WQIC serves as the primary water provider to the <br />Yuma Area Office. The facility purifies about one million gallons per day of drainage water <br />delivered either from the MODE, groundwater pumped from an on-site well, or Colorado River <br />water. The WQIC will continue to operate during calendar year 2004. <br /> <br />Colorado River Channel Aggradation Below Gila River Confluence <br /> <br />The 1993 Gila River flood deposited approximately 10 million cubic yards of sediment in the <br />Colorado River between its contluence with the Gila River and Morelos Dam. An additional <br />unspecified volume of sediment was deposited in the river channel below Morelos Dam. The <br />aggradation ofthechannel substantially reduced the river's capability to carry flood flows and to act <br />as a drain for groundwater, and has occasionally caused operational problems with the delivery of <br />Treaty water to Mexico at Morelos Dam. <br /> <br />