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 Colorado River

• 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 evaporation
• 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. Parker Dam
• 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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