Re: Siltation & Dams

[Michael Perelman <michael@xxxxxxxxxxxxxxxxx>]

Yes siltation is a big problem.  Generally the lifetime of dams is shorter
than initially predicted.

On Wed, Jun 27, 2001 at 04:38:35PM -0700, Tim Bousquet wrote:
> Now that I think about it, siltation is a big problem
> even here in CA. All these huge dams we've built don't
> last forever; they have projected lifetimes that
> depend on the rate of siltation. Shasta Dam, for
> example, was given a projected lifetime of 100 years
> when it opened in 1939-- after which the area around
> the dam will be so silted that water will flow over
> the top. There's also a down-stream matter of
> increased erosion as river bottoms are scoured but not
> replaced with new deposits, which are left behind the
> dam. I think I see how the problem could be at least
> mitigated with dredging, but I don't know why they
> would give a lifetime for the dam in the first place
> if the problem could be solved. Interestingly enough,
> 2039 is about when all the projected problems with
> global warming and the need for increased capacity
> kicks in. I'll find out more on this.
>
> tim
>
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--
Michael Perelman
Economics Department
California State University
Chico, CA 95929

Tel. 530-898-5321
E-Mail michael@xxxxxxxxxxxxxxxxx