<br />SUMMARY OF 2002 OPERATIONS
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<br />For at least the third consecutive year, dry conditions prevailed over the Colorado-Big Thompson
<br />Project (C-BT) area during Water Year 2002. According to weather experts. calendar year 2002
<br />was the driest on record in some areas of Colorado, Storage at most reservoirs deteriorated
<br />considerably after the dry calendar year of 200], Snowpack totals during Water Year 2002
<br />remained below average resulting in reservoirs over the area experiencing some of the lowest
<br />inflows in decades. Peak inflows in May and June did not last long enough to fill West Slope
<br />reservoirs to capacity. In fact, some were at record low storage levels,
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<br />Replacement of the ring seal gates for Green Mountain Reservoir penstocks, scheduled for the
<br />summer of2002 was, for the second consecutive year, postponed because of the lower than average
<br />inflows, The highest inflow into Green Mountain Reservoir was observed on June 1,2002. a 24-
<br />hour average of 555 ft3/s, In comparison, the previous year which was also considered to be a dry
<br />year, had a highest observed inflow of948 ftJ Is, In order to perform the work needed to replace the
<br />ring sea] gates, while at the same time continuing water deliveries to the Colorado River system. the
<br />reservoir level must reach the top ofthe radial gates. That level was never reached during the Water
<br />Year 2002,
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<br />Lake Granby also experienced the lowest total inflow for a Water Year in reservoir history. The total
<br />inflow for the Water Year 2002 was only ]] 1,300 acre-feet. In comparison, the 30-year average
<br />inflow is 252.930 acre-feet. The highest daily natural inflow was observed on June L 2002, an
<br />average of! ,234 ftJ Is, The reservoir content neverreached the spillway crest during the Water Year.
<br />therefore, no spil]s were observed, By September 2002, Lake Granby had reached its lowest water
<br />surface levels since the spring of 1990, 8216.56 feet above sea level. The reservoir level stabilized
<br />during October. as movement of water through Adams Tunnel was discontinued due to maintenance
<br />work at different C- BT facilities, In early November, 2002. the reservoir level began to decline once
<br />again, and by the middle of December. 2002, the total storage had dropped to less than 147,000 acre-
<br />feet.
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<br />Total inflow into Willow Creek Reservoir during the Water Year 2002 was also the lowest in
<br />reservoir history, The 15,600 acre-feet inflow was only one quarter of the 3D-year average, and
<br />9,000 acre-feet less than the previous low, recorded in 1977, The highest daily average inflow was
<br />reported on May 24, 2002, 74 ftl/s. The highest inflow for the previous year was 409 ftl/s,
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<br />Temperatures in general were relatively norma] during the winter, both on the West Slope and the
<br />East Slope, But, by the time spring arrived. temperatures were warmer than average, which
<br />contributed to the early snowmelt. Peak daily average inflows at Willow Creek and Granby
<br />reservoirs were observed in May and early June, During average weather years, peak monthly
<br />inflows at these two reservoirs are observed later in June. Wanner temperatures in the spring also
<br />contributed to more evenly distributed inflow totals for some of the reservoirs during the spring and
<br />summer months. The peak monthly-undepleted inflow at Green Mountain was observed in June,
<br />2002, a total of 36,300 acre-feet. That was 50.000 acre-feet lower that the previous year, and over
<br />90,000 acre-feet lower than the 3D-year average. Inflows into Green Mountain are dependent on the
<br />releases from Dillon Reservoir upstream, Dillon Reservoir experienced its highest monthly inflow
<br />in May.
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