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( Exhibit "B" con't) <br />upstream irrigation diversions. The average flow of the San Miguel River at <br />Uravan, 4 miles above the confluence with the Dolores River, is estimated at <br />107,500 acre-feet annually (U.S. Bureau of Reclamation 1978). <br />The water quality of the rivers varies considerably on a seasonal basis <br />because of fluctuation in runoff and in the volume of brine ground entering <br />the Dolores River as it passes through Paradox Valley. From 1971 to 1976, <br />concentrations of TDS in ware samples collected from the Dolores River <br />just above the confluence with the San Miguel River were greater than <br />12,000 mg/L; the primary constituents included bicarbonate, calcium, <br />chloride, magnesium, potassium, sodium, and sulfate (U.S. Bureau of <br />Reclamation 1978). Below the confluence, salinity of the Dolores River <br />decreases considerably during periods of low flow because of the inflow of <br />comparatively fresh water from the San Miguel River. <br />The surface water system in the area of Paradox Valley consists of several <br />ephemeral streams that flow only during wet periods of the year and after <br />unusually heavy rains. Runoff from the local watershed along the northeast <br />flank of Monogram Mesa drains towards East Paradox Creek and also <br />recharges the alluvial aquifer within Paradox Valley. Because of the <br />semiarid conditions in the Paradox Valley area, significant surface water <br />flows in ephemeral streams do not occur, and it is unlikely that flow from an <br />ephemeral stream ever reaches an active stream. (U.S. Department of <br />Energy July 2007). <br />