Friday, December 19, 2008

Colorado River Aqueduct

In recent weeks, I've taken trips to drive 4wd trails (Bradshaw Trail and Red Canyon Trail) in the Colorado Desert. Both have taken me past a curious site visible from the I-10 freeway. The Hinds Pumping Station sits north of the highway off the Hayfield exit. It originally was named the Hayfield pumping station, but was renamed in 1967 to Hinds after Julian Hinds (noted civil engineer who's escaped the notoriety of a Wikipedia entry). This is the last pumping station along the Colorado River Aqueduct before the water descends into Lake Matthews on the east end of the Los Angeles metroplex for use by many municipalities.

The Colorado River Aqueduct is an amazing thing. I am awestruck whenever I see sections of its open concrete lined canals. In these days of water scarcity, I can't help wonder how much water is lost to evaporation from those open canals.

This aqueduct stretches 242 miles from Lake Havasu to Lake Matthews, with 92 miles of tunnels, 63 miles of concrete canals, 55 miles of concrete conduits, and 144 siphons totaling 29 miles. This engineering marvel was named one of the 7 wonders of the American engineering world by the ASCE in 1992. Built between 1933 and 1941, it was conceived by William Mulholland and designed by Chief Engineer Frank Weymouth of the Metropolitan Water District of Southern California (MWD). It was the largest public works project in southern California during the Great Depression.

I found this really neat map of the aqueduct at the Herbert Hoover Presidential Library and Museum web site.

Hinds is the last of 5 pumping stations and raises the water 440 feet. Ron has posted some great photos of the station on his blog here.

During original construction of the Hinds station, the MWD got the clever idea to build a large reservoir at Hayfield to temoprarily store water during its journey west. Once built, in 1939, they filled it up and then watched as it slowly disappeared into the ground. Seems the bottom of the reservoir was too porous.

In 1999 the MWD reconsidered the plan and decided to store water in the local aquifer utilizing 50 wells with a capacity of 800,000 acre-feet of water. (1 acre-foot is approximately 326,000 gallons) Read more here.

If that wasn't enough of a problem, the OC Register wrote in October 2008 that the groundware there is contaminated with uranium and other toxic chemicals. Tests in 2000 show uranium contamination at an average of 16 picocuries per liter (highs of 35). EPA limits for drinking water is 20. That story includes this graphic comparing the levels at different locations.


Joe said...

Very informative. Now, the enquiring minds of LA want to know how many times you went for a swim in said aqueduct.

michael said...

LOL I'm sure they filter out any contaminants that I could possibly add to it. When I drove along the Coachella Canal, it was aggressively signed: No Tresspassing - Keep Out, etc. all along the edge.