Results and Analyses
Lake Paradise
Table 3 summarizes results of the 1979 and 2001 surveys of Lake Paradise. The lake lost
835 acre-feet (ac-ft) of its capacity as a result of sedimentation between 1908 and 2001.
Approximately 481 ac-ft of this loss has occurred since 1931, which gives an annual
sedimentation rate of 9.9 ac-ft since 1931.
If this rate of sedimentation continues, the volume of Paradise Lake will be
approximately half of the potential 1908 volume in the year 2013 and will be filled completely
by sediment in the year 2118. However, because of decreasing lake volume, trap efficiency of
the lake will tend to decrease with age, which very likely will extend the life of the lake.
Table 3. Reservoir Capacity and Capacity Loss Analysis for Lake Paradise
Period Capacity
Capacity
loss
Cumulative
capacity loss
Period annual
capacity
loss rate
Cumulative
annual capacity
loss rate
a) Analysis in units of acre-feet
1908 2,087
1931 1,942
1931-1979 1,461 481 481 10.0 10.0
1979-2001 1,252 209 690 9.5 9.9
b) Analysis in units of million gallons
1908 680
1931 633
1931-1979 476 156.6 156.6 3.3 3.3
1979-2001 408 68.1 224.7 3.1 3.2
Notes:
Lake surface area was 196 acres in 1931 (as determined for the 1979 survey).
Lake surface area was 166 acres in 1979.
Visual comparison of the 2001 shoreline with 1979 aerial photography did not indicate any
significant change in surface area.
Capacity shown is for the sedimentation survey conducted at the end of the period.
Spillway elevation was 684.5 ft-NGVD.
See report text for details on the adjustment of segment volumes for 1908-1931 period
sedimentation.
The 1931 volume is an interpolated value derived from 1908 and 1978 volumes.
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