From: houle@nmt.edu (Paul Houle)
Subject: Re: Different Transit Plans for Different Population Clusters
Organization: New Mexico Tech
Date: Fri, 21 Aug 1992 16:19:01 GMT

In article <JMC.92Aug20173346@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
>
>I assume that Dean Alaska is opposed to all dams.  If not he should say
>which areas were or should be mutilated by dams.  The question is whether
>he would use the word mutilate for something he favored or was neutral
>about.  Would he use the word mutilate for what will happen to an empty
>lot when he builds his house on it?

	Well,  I could dig up many more examples,  but two would suffice.
The first one is THE DAM,  I'm talking about Glen Canyon dam,  which is
probably the most hated object in the world by radical environmentalists
here in the US.  The formations around Glen Canyon are probably rather
stable,  so it is unlikely to suffer catastrophic failure (Nah,  one of these
days 'ol George is going to take care of that...),  but the construction of
the dam has replaced some of the most beautiful canyon country in the US
with a motorboat speedway.  Generally,  hydroelectric lakes in the west
provide a second-rate recreational experience.  Where they do have beaches,
it is not unusual to have 100-foot dropoffs close to the shore;  people get
killed at Elephant Butte lake all the time on account of these.  (On the
other hand,  these lakes do make for good cliff-jumping :-)  Also,  the people
who race around in nitro-powered boats and the water-skiers make it
hard on those of us who enjoy fishing,  sailing and canoeing.

	Of course,  recreation isn't the whole issue there.  One of them is
siltation.  The Colorado river has a very large amount of sediment,  and it's
estimated that siltation in Lake Powell will become a severe problem in the
next 100 years.  No simple answer to siltation exists,  because the removal
of silt would involve an earth-moving project literally hundreds of times
larger than the construction of the dam.  Also,  dams can cause a net loss
of water in a river system due to evaporation,  can alter aquifers (which
can cause landslides,  erosion and even catastrophic dam failures),  and
bend the flow rate downstream to the needs of electric generation,  affecting
the life cycle of everything downstream.

	Probably the most famous dam "failure" is that of the Aswan dam in
Egypt.  The Aswan dam had already lost a significant fraction of capacity to
siltation,  and has stopped the yearly cycle of floods and sediment deposition
which created the Nile delta and some of the most fertile cropland in the
world.  Due to evaporational losses much greater than expected and other
losses,  the dam only increases the irrigation capacity of Egypt by a factor
of about 1.5;  which isn't going to last once the dam becomes packed with
silt (which could happen in our livetimes)...  Seeing the rest of the
economic and environmental damage that has been done by it,  it seems like
a stupid investment in retrospect.

	Most hydro projects in the third world have turned out this way --
the additional irrigation they provide never seems to equal the amount
of cropland that is flooded and habitat that is destroyed.  Even in the US,
the only real consequence of "flood control" is that more people move into
flood plains,  the dams often flood over anyway,  and people get killed and
their posessions destroyed.  If we adopted rational landuse patterns that
reserve floodplains for agriculture and limited development (which means only
things that have a reason to be in the floodplain),  we'd benefit much more
than we do from so-called "flood control".
-- 
Xref: sparky sci.environment:10790 alt.politics.clinton:2512