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In water year 1990 , Upper Basin reservoirs had a decrease of 3,357,000 acre-feet in storage, and Lake Mead decreased storage by 1,399,000 acre- feet. Water supply conditions during water year 1990 have continued to be much below normal because of very little precipitation in the spring and summer months. During the next year, Reclamation will attempt to refill the mainstem reservoirs above Lake Powell. All the reservoirs should refill, with the exception of Flaming Gorge, which is expected to be approximately six feet short of filling. The refilling of the upstream reservoirs combined with the dry basin conditions are expected to reduce regulated inflow into Lake Powell by approximately 3.6 MAP. The most probable high con- tent of Lake Powell is expected to be just over 19 MAP. Considering the current amount of storage and the level of expected runoff, the risk of spilling is negligible. a. Lake Powell Lake Powell reached its high 3,665.20 feet on October 1, 1989, with a usable surface storage ofl9,805,000 acre-feet. By September 29,1990 the elevation was drawn down to 16,249,000 acre-feet, the minimum for water year 1990. At Lee Ferry, the calculated discharge for the water year ending Sep- tember 30, 1990 was 7,952,000 acre-feet, including approximately 11,000 acre-feet from the Paria River. Lake Powell finished the 1990 water year with a total annual release of 8.25 million acre-feet all of which went through the power plant. By careful planning and discussions among the Federal/State work group members, Western Area Power Administration, and the researchers involved in the GCES monthly release volumes were tailored to meet the winter and summer power demand patterns and the test flows required for the GeES within an 8.23 MAP release schedule. By careful coordination among the various agencies, the GCES test flows have been kept on schedule even though there was record-breaking heat in the Southwest during the water year. b. Flaming Gorge Reservoir The water surface of Flaming Gorge Reservoir on the Green River was at its highest elevation of the year on September 13, 1990, with usable surface storage of 3,093,000 acre-feet at elevation 6,023.26 feet. 58