Havasu Doug
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Posted: Oct. 23 2006,4:29 pm |
Post # 8 |
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| Quote | Environmentalist Perspective
by Rachel Craythorne
I currently work for the Grand Canyon National Park and I feel it is my duty to let people know of the damage mankind have done to this unique region of the world. As part of my daily life I see the destruction that the Hoover Dam and Glen Canyon Dam cause.
Who is to blame and why did the flood occur?
In 1983 the Dams were pushed to their limits as snow melt in spring exceeded predictions. As a result, Lake Mead and Lake Powell became too full and mounting pressure upon their structures caused the Bureau of Reclamation to release excessive amounts of water within 9 days, with no real plan or warning.
The US corp. of engineers and the Bureau of reclamation were responsible for the calculations of annual snow melt and precipitation and the maintenance of the reservoirs. Increasing temperatures may explain the increased snow melt, however this has only occurred due pollution of the atmosphere. Floods were a natural feature of the local area prior to the building of the dams. Because floods were frequent and small scale they created relatively little damage.
However, the land downstream of the dams had 'got used' to not being flooded, so the sudden increased flow lead to excessive damage that would not have occurred naturally.
Problems with the current dams
The freshwater reservoirs are very deep and have steep sides, neither of which factors lend themselves to habitats for flora or fauna. Bio diversity has decreased dramatically, with many native species being wiped out due to lack of naturally occurring habitats.
The Cottonwood, for example can no longer be found along the banks of
the Colorado. This is due to ground water depletion and inundation of the reservoirs, along with increasing industrial and agricultural pollution. Such plants rely on sandy beaches, a natural feature of the
local environment, and the annual floods.
Careless management practices have led to the serious decline native
fish population. Introduced game fish prey on the native endangered species, pushing them ever closer to extinction. By the very nature of rivers, the suspended load of the Colorado is dropped upon entering
both reservoirs. This is resulting in less and less storage room for water
as the reservoirs are being filled in by silt.
Once water is released from the reservoirs it has no suspended load. This causes increased vertical erosion in the areas downstream from the dams and yet more irreparable damage.
And the Future....
Initially, Lake Powell was necessary for the generation of hydroelectric
power and it's water storage. The power produced is no longer needed (more convenient alternatives have been introduced) and it's water storage is estimated to only be needed once in a century. This 1.3 million acre feet of water could, I'm sure, be put to better use in areas
such as Mexico, where large areas of land have become unproductive due to the lack of annual floods. Besides, areas such as Los Angeles that would have to rely on water stored in the Lakes can afford alternatives such as purification / desalination of salt water. Therefore I propose that the Glen Canyon Dam is no longer needed and draining of Lake Powell should begin immediately. However, I believe that the Hoover Dam should remain intact, and Lake Mead should only be part drained. The available storage space should then be utilised in times of high precipitation levels or excessive snow melt. |
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12-25-2025 Three Word Post.....The Next Generation.... (Rep.#20,039) from: BigDog
 Those dates helped me find the info I was looking for. Some info found on: 
