The Hydrological Cycle
The Hydrological Cycle
Water is a precious commodity in the American West. In the 1930's
the United States was in the middle of a serious depression (those
of you with living grandparents ought to ask them about this period).
Most of the population lived in the Eastern half of the United States.
Jobs were few, life was difficult. Coal fired steam plants provided
most of the energy and lots of pollution.
These conditions were the impetus to look towards the American
West for further expansion, colonization and development.
In order to fulfill the promise of the West, however, the land had
to be reclaimed from its desert state. Hence the creation of
the Bureau of Reclamation whose job it was to figure out how to
harness the energy and water of the American West river system
to reclaim the land from its arid state.
Their first target was the American Southwest:
and the Colorado River:
The story of the Colorado river is beautifully told, from all
points of view, in the video that will be shown today entitled
The Cadillac Desert Part 2: An American Nile . Pay attention
to this video as the first homework assignment will deal with it.
Below is a summary of the major events, with relevant links, of
the legacy of the Colorado river.
What happened to the
- Originally it reached northern mexico and fed a thriving
agrarian economy in the early 20th century
- Source is in Rocky Mountains of Colorado
- San Juan mountains in SW Colorado have a large snowpack
which feeds the river:
- In 1922 the water rights to the river were allocated
to California, Arizona, Nevada, Utah and Colorado
- Allocation was based on river flow during the period 1900-1920
which turns out to have been anomalously high therefore the
river was over-allocated
- Depression hits so Hoover dam is built as part of the effort to
reclaim the West
(see also the excellent Cadillac Desert Series )
- Water backs up into reservoir and increases surface area to
- Reservoir lined with porous sandstone so water loss due to
seepage into sandstone occurs
- Lake Havasu
was created for London Bridge additional
recreational dams were built (e.g.
- As more and more of the Colorado became prone to evaporation
its salinity increased
- Eventually the water that reached Mexico was too saline for
agriculture. Mexican government sued and won. US built a
desalination plant in Yuma Arizona
- Now no water gets there ... unless we really
pour it on:
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