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<br />The Price-San Rafael Rivers Unit is located in east-central Utah, 120 miles southeast of Salt Lake <br />City, encompassing Carbon and Emery Counties. Agriculture and energy development (primarily <br />coal mining) make up the principal economic base in the area. Both the Price and San Rafael Rivers <br />drain into the Colorado River via the Green River. <br /> <br />...... <br />C.J1 <br />to.... <br />N <br /> <br />Salinity contributed to the Colorado River from the Price and San Rafael River Basins occurs <br />principally as a result of the dissolution of soluble salts in the soil and substrata. Return flows from <br />irrigation and runoff from precipitation transport salts to natural draiDs and eventually into the streams <br />and rivers. An estimated 430,000 tons per year of salt reach the Colorado River from these two river <br />basins. Of this amount, approximately 60 percent is attributed to agriculture. <br /> <br />Five alternative plans have been evaluated by Reclamation. These alternatives include: (1) improving <br />irrigation systems; (2) using drain water for powerplant cooling; (3) collecting saline water and <br />disposing of it through deep-well injection, evaporation ponds, or a desalting plant; (4) using saline <br />water for energy development (coal washing, tar sands, or coal slurry pipeline); and (5) retiring land <br />from irrigation. Of these, the irrigation systems improvement alternative passed the four tests of <br />viability (completeness, effectiveness, efficiency, and acceptability). <br /> <br />The plan currently being evaluated combines the Reclamation and USDA programs of irrigation <br />improvements. Water pressure developed by piped laterals would be used to run sprinkler irrigation <br />systems. The plan would also eliminate winter water from the canal system by installing a rural <br />domestic water distribution system. This would be similar to the winter water program in the Lower <br />Gunnison Basin Unit. <br /> <br />San Juan River Unit <br /> <br />The San Juan River Unit investigations began in November 1985 with the objectives of locating salt <br />sources and identifying control methods. The study area includes the entire 23,OOO-square-mile <br />watershed from its headwaters in south-central Colorado to its mouth at Lake Powell. The drainage <br />contributes approximately I million tons of salt annually to the Colorado River Basin. Early <br />reconnaissance shows significant salt loading in the river between Shiprock, New Mexico, and the <br />Four Comers area. At Bluff, Utah, the annual flow of 2,047,000 acre-feet of water contains <br />1,165,000 tons of salt. About 18 percent of this salt loading occurs between Shiprock and Bluff, but <br />only 7 percent of the water is added in this reach. <br /> <br />The study area was broken into about 20 subwatersheds and geographic areas. Since November <br />1985, water quality sampling and flow measurements have been made throughout these subbasins to <br />gain an understanding of salinity mechanisms. The study area covers many thousands of square miles <br />of natural resource lands as well as agricultural, municipal, and industrial areas which may contribute <br />controllable salt. Most of the nablral source of salt is contributed by surface runoff and ground-water <br />discharge from the Nacimiento and Mancos Shale Formations. Many thousands of acres of vegetation <br />along the streams and washes worsen the conditions by concentrating the salts. Irrigation projects, . <br />coal-fired powerplants, surface mining operations, oil and gas fields, and refinery operations also <br />contribute to the salinity problems. <br /> <br />The Hammond Project, Navajo Indian Irrigation Project (NIIP), and the Hogback Irrigation Project <br />(also a Navajo Indian project) are the principal irrigation sources of salt in the San Juan River Basin. <br /> <br />36 <br />