Projects to add Colorado River water storage

According to an agreement reached last week, Arizona plans to invest nearly $30 million in a new reservoir near Yuma to buy the state more water and added insurance against future shortages.

The reservoir will be built about 25 miles west of Yuma along the All American Canal at the former Brock Ranch Experimental Research Station in Imperial County, said Jack Simes, spokesman for the Bureau of Reclamation in Yuma. Construction is expected to begin this year on the project proposed to capture water that now flows unused into the ocean.

"It really is protecting the future," said Susan Bitter Smith, president of the Central Arizona Project board of directors, which agreed to the deal last week. "We don't know what will happen 15 or 20 years from now. This will help us augment supplies for the future."

The deal also buys a measure of goodwill on the lower Colorado River. Nevada and California face more immediate needs and will benefit first from the water stored at the reservoir.

Currently, when it rains or there is unused river flow, there is no place to store the water below Imperial Dam either in the U.S. or Mexico, Simes said. "So the water doesn't go to any beneficial uses.

"The project has been proposed for a long time," Simes said.

The structure was included in the seven-state drought plan adopted in December. Nevada originally agreed to pay the full $172 million cost of the reservoir in return for access to more water but approached Arizona and California late last year about buying shares of the project.

Arizona will receive a one-time water allocation of 100,000 acre-feet, or about 32.6 billion gallons. An acre-foot of water is the amount that would cover an acre to the depth of 1 foot, or 325,851 gallons.

The proposed project, called the Drop 2, would include a reservoir with 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 could save on average approximately 70,000 acre-feet of Colorado River water a year, ultimately reducing the amount of water released from Lake Mead, according to an environmental assessment of the project.

"It will be a good thing for the system," Simes said. "It will enhance the lower Colorado River storage capacity."

The Metropolitan Water District of Southern California is expected to buy an equal share in the reservoir for the same $28.7 million contribution. The district's board will consider the proposal in April.

The Southern Nevada Water Authority will pay the remaining $115 million and will gain access to 400,000 acre-feet of water. The agency also will cover cost overruns in exchange for additional water.

In another project to increase lower Colorado River storage, capacity will be expanded at Laguna Dam, Simes said. That project is expected to add approximately 1,300 acre-feet of storage capacity.

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Sun staff writer Joyce Lobeck contributed to this report. She can be reached at jlobeck@yumasun.com or 539-6853.