This paper describes the problem of
sedimentation in reservoirs,in general,
and offers an estimate of the annual
rate of storage loss and the useful life
of Sefidrud reservoir in Iran,in particular.
The life of Sefidrud reservoir
was predicted to exceed 100 years in
the design, based on insufficient data.
Regular daily measurements of sediment
discharge of the river, taken years later,
however, indicated much higher rates
of sediment deposition in the reservoir.
These measurements have shown
that 56 million tons of suspended sediments
enter the reservoir annually of
which more than 80 percent (mostly silt
and clay) is trapped. Based on these measurements,
the actual useful life of
the reservoir is calculated to be only
about 30 years.
Amongst various methods of sediment
control, improving the operation program
of the reservoir is suggested as a
practical means of reducing sediment
trap in Sefidrud reservoir. Of course,
this method, as any other, does not
provide a definite solution to the problem,
but may increase the remaining
life of the Sefidrud reservoir by two
to three years.
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