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Re: renewable energy



not long ago PBS did a feature on dam building from ancient times. I
remember their showing evidence of a massive failure of an ancient dam.

bc


Hugh Haskell wrote:

At 8:45 -0700 8/11/02, Leigh Palmer wrote:

It is my impression (gained from experience in British Columbia)
that dams are somewhat marginal - they are built just sufficiently
robustly that they work, and no stronger. As a result significant
leaks are not uncommon, not usually in the structure itself, but
rather in the soil and rock at the margins of the dam.

And leaks at the margins of the dam can be especially pernicious, by
eroding the very foundation that supports the dam and holds it in
place. There have been any number of major dam failures caused by
just such leakage. IIRC the famous Johnstown flood in PA was caused
by just such erosion around a dam built upstream of the city.

One has to wonder at the intelligence of planners that would build a
dam just upstream of a city, especially if they are going to build it
with the bare minimum of safety factors. I'm reminded of Will Rogers'
homily, "don't drink the water downstream of the herd."

Hugh
--

Hugh Haskell
<mailto:haskell@ncssm.edu>
<mailto:hhaskell@mindspring.com>

(919) 467-7610

Let's face it. People use a Mac because they want to, Windows because they
have to..
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