Tuesday, April 24, 2007

Land Sinking

This might drain some of the weight out of the argument to store water underground rather than above it. :)

Sinking on the west side
Because of dry conditions, farmers have had to pump water from underground, causing the ground to deflate.
By Mark Grossi / The Fresno Bee

World-class farmland is sinking on Fresno County's west side.

The land dipped 30 feet between 1925 and 1977 near Mendota -- and it's still going down in what the U.S. Geological Survey calls "the largest human alteration of the Earth's surface." Ever.

The soil has deflated as deep-water pumping for farm irrigation drains away ground water. The dropping ground level is responsible for millions of dollars in damage to irrigation canals and could threaten such landmarks as the California Aqueduct and Interstate 5.

The Central California Irrigation District already faces the need to spend up to $6 million to fix one of its main canals. Eventually, the district's Mendota Dam, a key feature of the west side's irrigation network along the San Joaquin River, will need to be replaced as a result of the sinking soil.