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<br />OL2133 <br /> <br />PROGRMI GOALS AND OBJECTIVES <br /> <br />The primary objective of the CRSC program is to reduce salinity in the <br />Colorado River a level consistent with establislled water quality standards <br />while allowing States to continue development of water apportioned to them by <br />various cowpacts and court Jecrees. lhe current Colorado River numeric <br />criteria for salinity is measurel1 as cotal dissolved solids (TDS) and have <br />been established by the Basin States and approved by EPA. The numeric <br />criteria for salinity are as follows: <br /> <br />Below Hoover Dam <br />Below Parker Dam <br />At Imperial Dam <br /> <br />723 mg/l <br />747 mg/I <br />u79 mg/l <br /> <br />Historically, the Colorado River carries about 9 million tons of salt in about <br />10 million acre-feet of flow past Hoover Dam each year. Natural diffuse <br />sources and saline springs provide about one-half of the salt, agricultural <br />irrigation return flows contribute about one-third, and municipal and <br />industrial sources add the remaining salt load. <br /> <br />As the Basin States continue to develop their waters, the Coloraao River flows <br />are projected to decrease by 2.7 million acre-feet per year by the year 2010. <br />As flows are reduced, salinity levels are projected to reach about 960 mg/l by <br />2010. The projected salt load reduction needed to maintain salinity <br />concentrations for TDS at or below the adopLed nuweric criteria in the lower <br />mainstream of the Colorado River is about 1 million tons per year. Therefore, <br />the program objective is to reduce the averal\e annual salt load by <br />approximately 1 million tons. l'igure 2 displays the salinity projection <br />without further controls. These projections are based upon average long-ter~ <br />flows in the river, estimated future water development, and the combined <br />removal of about 141,000 tons of salt per year from existing USDA and USBK <br />salinity control projects in Grand Valley, Unita Basin, Meeker Dome, and Las <br />Vegas "ash. The projected 2010 salinity level in Figure 2 assumes that the <br />level of existing salinity reduction will continue and that no further control <br />will be implemented. Figure 3 shows the salinity level, assuming furu,er <br />controls. <br /> <br />As a part of the USDI and USDA joint evaluation process for the CRSC program, <br />it was determined that a cost-effective mix of both USDA and USDI programs is <br />needed. The salt load reduction goal cannot be achieved by either a USDI or <br />USDA salinity control program alone. In many cases, it is necessary for USDI <br />and USDA projects to be implemented together. The off-farm canal and lateral <br />improvements by USBR are often required before the more cost-effective onfarm <br />improvements can be initiated. The off-farm improvements usually allow <br />individual irrigators to install more efficient and cost-effective gravity <br />pressure sprinkler systems. The USDA and USDI implementation plan to achieve <br />the necessary salt load reduction has an estimated total Federal cost of $560 <br />million. <br /> <br />rne USDA implementation schedule would include nine projects and is estimated <br />to achieve the removal of 662,000 tons of salt per year or over 50% of the <br />projected 1,177,000 tons of salt load reliuction. The uSDA onfarm projects <br />assume about 40% of the total construction cost needed to implement the <br />program. The USDA and USDI combined implementation schedule, assuming <br />sufficient funds are available, is shown in Figure 4. <br /> <br />6 <br />