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<br />2.00 inches for the watershed. The average precipitation total for the month is
<br />1.46 inches. But, the additional precipitation did not influence the inflow, which dropped to only
<br />51 percent of average. Total April-July inflow was 31,780 acre-feet or 64 percent of the 30-year average,
<br />one of the lowest on record. Precipitation continued to be well above average during July at 210 percent.
<br />Total monthly bypass releases were 4,200 acre-feet for May, 6,400 acre~feet for June, 3,400 acre-feet for
<br />July, 1,700 acre-feet for August, and 1,000 acre-feet for September. August precipitation was also above
<br />normal at 126 percent of the 30-year average, as the inflow increased to 100 percent of the 1966-1995
<br />average.
<br />
<br />With the rainy season over, September precipitation dropped below average once again. The
<br />1.15 inches reported represented only 86 percent of the 30-year average. As expected, by the end of the
<br />water year, natural inflow average was only 73 percent, which amounted to 42,900 acre-feet.
<br />
<br />During the water year 1998,24,800 acre-feet of controlled releases were made from Willow Creek. Lake
<br />Granby storage volume was higher than average during water year 1998. Excess volumes at Willow
<br />Creek Reservoir were bypassed into the river, as the storages at Lake Granby remained high. These
<br />optimizing operations at the Willow Creek Project resulted in significant savings in pump energy costs.
<br />However, between the months of May through June, 1998, as storage became available, 15,024 acre-feet
<br />of water were pumped to Lake Granby. .An additional 119 acre-feet were pumped dining October, 1997,
<br />as well as 1016 acre-feet during August, 1998, and 859 acre-feet during September, 1998. The 17,137
<br />acre-feet pumped into Lake Granby, represented only
<br />53 percent of 30-year average. By the end of September, 1998, the volume stored at Willow Creek.
<br />Reservoir had reached 9,400 acre-feet.
<br />
<br />Granbv Reservoir
<br />
<br />Completed in 1950, the Granby Reservoir on the upper Colorado River collects and stores most of the
<br />project water supply for the Project. The reservoir stores the flow of the Colorado River as well as water.
<br />pumped from Willow Creek Reservoir. The reservoir has a total storage capacity of 539,800 acre-feet.
<br />The spillway is located on the left abutment. Flow over the spillway is controlled by two radial gates,
<br />which have a total release capacity of 11,500 ft%. The Granby Pumping Plant has three units with a
<br />combined installed capacity of 600 ft3/s.
<br />
<br />Reservoir carryover storage into water year 1997 was 532,455 acre-feet, which were 118,785 acre-feet
<br />above the 30-year average of 413,670 acre-feet.
<br />
<br />October-January precipitation was 78 percent of 30-year average, while the inflow for the same period
<br />was 125 percent.
<br />
<br />Reservoir releases throughout the water year were higher than normal. The total volume of water spilled
<br />for the water year 1998 was 32,000 acre-feet, almost 3 times the 30-year average.
<br />The spill occurred between the months of April and July, 1998. Regulated releases for the water year
<br />totaled 25,500 acre-feet, 12,270 acre-feet lower that the 30-year average of 37,770 acre-feet.
<br />
<br />The February 1 snowpack water content was reported at 92 percent of average, resulting in an April-July
<br />runoff forecast of 195,000 acre-feet. Precipitation totals for the watershed below average between the
<br />months of October and January. The total precipitation recorded for that period was 3.90 inches, 1.10
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