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<br />NAVAJO RESERVOIR
<br />(SAN JUAN RIVER)
<br />
<br />
<br />Water Year 1987
<br />
<br />The completion of the concrete cutoff wall, part of the dam
<br />safety modification work on Navajo Dam, was fInished during
<br />water year 1987. The elevation of Navajo Reservoir at the
<br />beginning of the water year was 6,072.3 feet with 1,508,000
<br />acre-feet of active storage, It was planned that Navajo
<br />Reservoir with an average 1987 runoff year would be drawn
<br />down to near elevation 6,042 feet by April 1987, in preparation
<br />for the completion of the dam modification work,
<br />
<br />Navajo Reservoir was gradually drawn down to elevation
<br />6,066.3 feet by January I, 1987, and the April through July
<br />runoff forecast at this time was 775,000 acre-feet or 122
<br />percent of average, Releases of 2,820 cfs were maintained
<br />through January and most of February, On March I, the
<br />runoff forecast increased to 825,000 acre-feet, which was 130
<br />percent of average, This dictated that releases be increased to
<br />3,020 cfs for the month of March, The forecast made on April
<br />1 .increased again, to 925,000 acre-feet or 146 percent of
<br />
<br />ACTUAL RELEASES
<br />
<br />WY 1987
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<br />average, Subsequently, releases of 4,540 cfs were held
<br />constant for the entire month of April and for the first few
<br />weeks of May, On June 1, the forecast remained unchanged,
<br />although inflows increased rapidly due to the snowpack
<br />melting from warmer weather. An inflow of 7,380 cfs occurred
<br />on June 16, resulting in releases being increased to 5,040 cfs
<br />in order to keep tbe reservoir surface elevation from rising.
<br />
<br />The actual April through July 1987 runoff volume into Navajo
<br />Reservoir was 1,072,000 acre-feet, or 169 percent of average,
<br />The total water year 1987 intlowwas 1,771,000 acre-feet which
<br />was 185 percent of average, Peak inflow to Navajo reservoir
<br />occurred on April 25, at 7,520 cfs and the peak releases were
<br />5,040 cfs from June 3 through July 20. The reservoir reached
<br />a peak elevation of 6,055,7 feet on June 19, and the desired
<br />drawdown elevation of 6,042 feet was reached on April 7,
<br />1987, The spillway at Navajo Dam was not used during the
<br />w.ater year.
<br />
<br />NAVAJO RESERVOIR
<br />
<br />Reservoir
<br />
<br />Acre-feet
<br />
<br />Elevation, feet
<br />
<br />Maximum Storage
<br />Inactive Storage
<br />Surface Area, full
<br />Reservoir Length, full
<br />
<br />1,696,400
<br />660,500
<br />
<br />6,085
<br />5,990
<br />15,610 Acres
<br />33 Miles
<br />
<br />11
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