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U.S., Mexico Near Start of Aqueduct Study

By Steve La Rue
The San Diego Union Tribune, September 7, 1999


It would heave tens of millions of gallons of water over 175 miles of desert and mountains, stitching the international border with a thread of water weaving in and out of the United States and Mexico.

This ambitious vision -- an international border aqueduct to bring Colorado River water to Tijuana and San Diego County -- also could trigger energetic opposition.

Any day now, bureaucrats and engineers in the United States and Mexico are expected to finalize a set of agreements that will launch an 18-month, $3 million study of how and where to build such an aqueduct, figure out how much it would cost, and determine how much it would benefit both sides of the border.

All of the money would come from the U.S. side -- $500,000 from water bills paid in San Diego County and $2.5 million from the state of California. Mexico would contribute engineering work and other support.

Costs for the aqueduct itself are expected to be shared on the basis of how much water is delivered to each side of the border.

An international aqueduct could provide a fail-safe route for San Diego County to receive conserved farm water from the Imperial Valley, as well as other water from other Colorado River sources, such as by financing conservation projects in other river states.

One solid backer of the idea is state Sen. Steve Peace, D-El Cajon.

"I don't think there is any question that this eventually will happen," he said. "The question is how soon. It is critical to Mexico in meeting their economic and health needs.

"By working cooperatively with the Mexican government, we can make it a more efficient project, and one that will supplement the water needs in San Diego."

A new aqueduct would free San Diego County from having to negotiate with the Los Angeles-based Metropolitan Water District, supplier of up to 95 percent of San Diego County's water, for space in the MWD's 242-mile Colorado River Aqueduct.

The MWD aqueduct is currently the only way San Diego County can receive an independent supply from the river, and water officials here fear that the MWD would like to close off this option.

Peace said a new water artery to the east also would give San Diego County a vital supply in the event that an earthquake severed the MWD's aqueduct or smaller aqueducts that deliver MWD water south to this county.

Baja California would receive more of its entitlement of Colorado River water, and more reliably, than its small, 1983-vintage aqueduct can provide.

"At around the year 2004, the water demand in the city of Tijuana, Baja California, will exceed supplies of this precious liquid," said Francisco Oyarzabal Tamargo, regional manager of Mexico's National Water Commission for Baja California. "Similarly, in the year 2008, the city of San Diego will require additional supplies.

"The possibility of the U.S. and Mexico cooperatively constructing and operating an aqueduct will have the advantage that the costs for operation and construction would be shared in proportion to the water delivered. The combination of effort would reduce the costs."

The San Diego County Water Authority, a coalition of 24 cities and water districts that imports water from the MWD, would be the lead U.S. agency on the project.

"One of the ground rules we have always operated under in this study is that the U.S. would transport water the U.S. already owns and Mexico would transport water it already owns," said Ken Weinberg, director of water resources.

In other words, he said, the purpose of the new aqueduct would not be to increase the volume of river water taken by California. But this assurance might not assuage the six other states that rely on Colorado River water. California already is siphoning 18 percent more water from the river than its legal entitlement, and these states in the past have criticized a new aqueduct as little more than "another straw" that would enable California to guzzle even more.

"They aren't going to like it at all; they don't like us anyway," said James Bond, the water authority's delegate to the Colorado River Board, which is made up of Southern California agencies that rely on river water.

Some Imperial Valley water officials also oppose such a project.

The other river states may not be able to prevent construction of an international aqueduct, but they could withhold the cooperation that California is seeking from them in proposals to adjust operating rules for the Lower Colorado River.

The California Department of Water Resources would pay $2.5 million of the study's cost from proceeds of Proposition 204, approved by voters in November 1996, which authorized $995 million in bonds for a range of water projects and studies.

The water authority would pick up the remaining $500,000. Mexican agencies would participate in planning and engineering the project, but would not help finance the study, Weinberg said.

"Right now, this is just a technical study of the alternatives, to be able to evaluate them," he said. "We have realized that Mexican participation financially could make this a more cost-effective project, so we are working together to be able to build something larger and share in the cost."

The study also will determine whether new reservoirs may be needed to hold the binational water at the end of the aqueduct, whether treatment plants might be needed to reduce pollutants and salinity, and what funding sources may be available.

How much might such a project cost? A September 1996 study of pipelines that the water authority was considering on the U.S. side looked at five alignments.

The consulting firm of Black and Veatch Co. estimated that aqueducts ranging from 140 to 240 miles long could cost from under $1 billion to $2 billion in 1996 dollars, with water pumping and treatment costs adding up to an additional $92,000 a year.

Costs have increased since then, but land, labor and environmental costs would be lower on the Mexican side of the border.


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