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<br />July water supply forecast was 350,000 acre-feet, which was 136 percent of average. Precipitation
<br />jumped to 189 percent of average, and April inflows stayed high at 147 percent of average.
<br />Precipitation and inflow remained high during the month of May for the Green Mountain Reservoir
<br />watershed. Precipitation was estimated at 130 percent of average, while inflow was estimated at
<br />162 percent. Turbine releases were increased to 821 ft3/s on May 3, 1997, in anticipation of an
<br />increase in the daily inflows. By the end of the month, turbine flow had surpassed 1,100 ft3/s.
<br />
<br />In June, releases were increased dramatically because of the steady increase in inflow. By the
<br />middle of the month, turbine releases had been increased to 1,525 ft3/S, and gated releases had
<br />reached over 500 fe/so The high turbine releases continued throughout the month, while the gated
<br />releases continued to increase until they reached a peak on June 25, at 1,724 ft3/s, for a combined
<br />flow of 3,187 ft3/s.
<br />
<br />Reservoir storage reached the year's low of 62,859 acre-feet on May 6. A targeted storage of 60,000
<br />acre-feet at the end of April is desired for the most probable runoff condition, while 50,000 acre-
<br />feet is desired for the maximum runoff condition.
<br />
<br />April and May precipitation were well above average in the Blue River watershed. Due to the
<br />expected high runoff conditions, Dillon Reservoir spilled from early April through the end of
<br />September 1997. Dillon Reservoir filled to capacity on July 9, 1997. The storage volume peaked
<br />on August 7 at with a total volume of 257,351 acre-feet. Spillway discharge at Dillon reached a
<br />maximum of 1,692 ft3/s by June 14, 1997. The spill continued through the end of September for a
<br />total of 185,255 acre-feet in water year 1997. Dillon Reservoir ended the water year at a storage
<br />level of 254,134 acre-feet, which was 107 percent of average for the years 1966-1995 (236,800
<br />acre-feet).
<br />
<br />By May 30, turbine releases from the Green Mountain Power Plant were increased. The increase in
<br />the flow was part of a coordinated effort among different agencies to enhance the spring peak flow
<br />along the Colorado River. The incoming inflows were passed through with a maximum flow of
<br />1,500 ft3/s.
<br />
<br />Throughout mid June, releases from the reservoir were increased even more to delay the filling
<br />process. Computed inflow to Green Mountain Reservoir peaked for the year at 3,390 fr3/s on June
<br />20, 1997. June precipitation was only 84 percent of average, but inflow remained above average at
<br />172 percent of average. On Friday, July 30, 1997, the water level had reached 7,949.86 feet, with a
<br />total storage of 153,343 acre-feet. Water was not spilled after July 7, although turbines were
<br />increased to well over 1,1O0 after July 30. During June, July, and August the inflow and turbine
<br />releases remained high due to the spill at Dillon Reservoir and high snowmelt runoff conditions.
<br />Turbine releases were at the maximum capacity of 1,500 fr3/s for the last two thirds of June and the
<br />first two days of July. The July un depleted inflow of 86,298 acre-feet was 122 percent of average.
<br />Actual April-July runoff was 417,700 acre-feet, 151 percent of average, and 77,700 acre-feet more
<br />than the April 1 forecast of 340,000 acre-feet.
<br />
<br />Due to the spring and early summer rain and snowmelt, no requests were received for water from
<br />the Green Mountain Reservoir. The recorded flow at the Dotsero gage was 2,406,300 acre-feet for
<br />water year 1997, which was 161 percent of average. The August and September inflows into Green
<br />Mountain Reservoir for water year 1997 were 166 percent of average and 158 percent of average,
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