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<br />Granbv Reservoir <br /> <br />Completed in 1950, the Granby Reservoir on the upper Colorado River collects and stores most <br />of the project water supply for the Project. The reservoir stores the flow of the Colorado Ri ver as <br />well as water pumped from Willow Creek Reservoir. The reservoir has a total storage capacity <br />of 539,800 acre-feet. The spillway, located on the left abutment, is controlled by two radial gates <br />with a total release capacity of 11,500 ft3 fs. The Granby Pumping Plant has three units with a <br />combined installed capacity of 600 ft3 Is. <br /> <br />Reservoir carryover storage into water year 1999 was 495,533 acre-feet, which were 81,830 acre- <br />feet above the 30-year average of 413,670 acre-feet. <br /> <br />October-January precipitation was 132 percent of average, and October-January inflow was 138 <br />percent of average. <br /> <br />During the months of September and October, 1999, Granby released 14,160 acre-feet and <br />12,626 acre-feet respectively. This amount is beyond the typical 1200 acre-feet per month that is <br />the minimum flow required for fish release. <br /> <br />The February 1 snow-pack water content was recorded at 103 percent of average, resulting in an <br />April-J ul y runoff forecast of 215,000 acre-feet. February precipi tation was below average at 54 <br />percent of the 1966-1995 average. Inflow for February continued below average at 77 percent. <br />March I snow-pack water content was 99 percent of average, which maintained the April-July <br />runoff forecast at 215,000 acre-feet. March precipitation was way below average at 35 percent, <br />and inflow was 138 percent of average. April 1 snow-pack water content was 77 percent of <br />average, and the April-July runoff forecast decreased to 175,000 acre-feet. <br /> <br />Lake Granby storage on March 31 was 439,685 acre-feet, which was 143,585 acre-feet above the <br />1966-1995 average. <br /> <br />April was a dry month as precipitation was 72 percent of average. The May 1 snow-pack water <br />content continued below average at 81 percent and the dry April decreased the April-July runoff <br />to 175,000 acre-feet. April inflow was 111 percent of average. <br /> <br />May precipitation continued below average at 69 percent of the 1966-1995 average, while the <br />inflow was 90 percent of average. The October-May inflow was 104 percent of average. <br /> <br />Precipitation during June continued to be below average at 86 percent of average. Inflow was <br />above average at 108 percent of the 1966-1995 average. Lake Granby storage continued to rise <br />rapidly, reaching a peak of 537,224 acre-feet by June 29. The water surface elevation at that <br />point was 8279.65 feet, which was 0.35 feet below maximum operating level. Lake Granby is <br />required to initiate a spill when the water surface elevation reaches 8279.50 feet. Natural inflow <br />peaked on June 28 at 2,590 ft3/S. Adams Tunnel diversions were near maximum capacity during <br />June as the Eastern Slope runoff and storage conditions allowed. Spillway releases were initiated <br />on June 1, 1999 and the total spilled for June was 20,821 acre-feet. The peak spillway release <br /> <br /> <br />]2 <br />