New reservoir to conserve Colorado River water
By: Joyce Lobeck

Not all the work that travelers can see along Interstate 8 is for the construction of a new concrete-lined stretch of the All American Canal.

Crews also are in the midst of constructing a new water storage reservoir about 25 miles west of Yuma where the former Brock Ranch Experimental Research Station was located.

That's the reason for a slight detour along I-8 while crews lay 9-foot pipes under the freeway. Or the sight of cranes where palm trees once were located on the north side of the freeway.

Once completed, the polyethylene-lined two-cell reservoir will have a storage capacity of 8,000 acre-feet of water and inlet and outlet structures to connect the reservoir to the All American Canal. It is anticipated that the reservoir will capture about 70,000 acre-feet of Colorado River water a year for future use.

As of late 2009, the project was about 88 percent completed, said Michael Vandevelde, project manager. Anticipated completion was September 2010, but the project is ahead of schedule and may be finished earlier.

A key factor in selecting the location, he said, is that it's near the turnout where a portion of the All American Canal is diverted to the Coachella Canal. That structure was modified and additional gates added to also allow flow into the 6-1/2-mile concrete-lined inlet canal that feeds the reservoir.

It's also an area where a decline allows for the gravity flow of water with no need for pumps, he said.

The former experimental station provided a semi-developed location, although the area still had to be cleared of old citrus trees, a building and underground utilities, he said.

The inlet canal can carry 1,800 cubic feet of water a second to fill the reservoir in three days. In turn, the outlet canal that leads back to the All American Canal can empty the reservoir in three days.

The reservoir had been proposed for some time and finally is becoming a reality through an agreement among the Central Arizona Project, Metropolitan Water District of Southern California and the Southern Nevada Water Authority.

The three agencies are splitting the $172 million cost in turn for sharing in the Colorado River water that will be saved - water that is critically needed in the midst of a lingering drought even as demand by thirsty cities has increased.

The project will capture flows that cannot be used by entities downstream from Parker Dam, such as irrigation districts.

"It takes three days for the water to get from there to the canal," Vandevelde said. "If it rains and the water isn't needed, there isn't much that can be done as the water is on its way."

Senator Wash can hold some of the water, but the rest of it ends up going to the ocean, he said. With the completion of the reservoir, the previously unstorable flows will be diverted into the All American Canal, then to the reservoir until needed by the Imperial Irrigation District. In turn, the three funding agencies will receive additional water from Lake Mead.

During the project, public access to the sand dunes has been maintained, Vandevelde said.

Once construction is completed, the reservoir and canal facilities will be permanently fenced off.