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The role of science in restoring California's water resources

Few issues in California are as contentious as water

That`s particularly true in Northern California, where snowmelt from the Sierra Nevada mountains is siphoned off to meet drinking and irrigation needs for the rest of the state.

But as California`s population continues to grow, so does concern over the future of its liquid assets. Today many residents are calling for a balanced approach to water management - one that meets the demands of thirsty farms and cities while protecting Northern California`s fragile rivers and lakes.

The critical role played by environmental scientists in solving the state`s complex water issues will be the subject of a symposium at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Francisco on Tuesday, Feb. 20, at 8 a.m. PT.

Hydrologist David L. Freyberg, an associate professor of civil and environmental engineering at Stanford, is one of a half-dozen experts from around the state invited to address the three-hour conference.

``The social, political and economic life of California is completely entwined with its water resources,`` Freyberg says, ``and the next few years are likely to be particularly interesting.``

Energy crisis

Freyberg points out that water is intimately linked to California`s most urgent crisis - the shortage of electricity resulting from deregulation of the state`s utilities. The power crisis, which caused rolling blackouts and skyrocketing utility bills in January, has been exacerbated by a lack of rainfall. That`s because most electricity in the Golden State is produced by hydroelectric dams, and when water reservoirs are low, electrical production drops.

Fear of additional shortages has led some political leaders to call for increased hydropower production, but Freyberg cautions that state policy makers must weigh the environmental impact of all new water projects.

``Understanding the biological effect of releasing dammed water requires that we understand the intricate food webs that exist downstream,`` Freyberg says.

``I don`t see any new dams being built in California,`` he says, noting that ``dams are being removed as we speak to restore damaged ecosystems.``

California Aqueduct

``There`s a lot of water in California,`` observes Freyberg, ``but not where people live.``

In fact, most Californians reside in the southern part of the state, in arid desert communities such as Los Angeles, Anaheim and San Diego. And California`s multibillion-dollar agriculture industry - which produces 45 percent of America`s fruit and vegetables - is concentrated in the vast Central Valley, where rainfall is scarce during the summer and fall growing seasons.

Californians tried to correct the north/south water imbalance in the 1960s by constructing a controversial 700-mile artificial river known as the California Aqueduct - the largest water conveyance project in the world. This system of concrete canals diverts millions of acre-feet of water from the Sacramento-San Joaquin River Delta in the north to Southern California and the Central Valley.

``When we alter water distribution on that scale,`` says Freyberg, ``it significantly changes the environment, particularly riparian ecosystems that are extremely important to wildlife and fisheries.``

Restoration of the Sacramento-San Joaquin Delta is a major challenge for state policymakers, Freyberg notes. The Delta - a huge wetland ecosystem that drains into San Francisco Bay - provides drinking water to 20 million people, irrigates millions of acres of farmland and serves as a recreational playground for thousands of boaters and anglers.

Decades ago, the Delta teemed with fish and wildlife, but development, pollution and aqueduct diversion have taken their toll.

In March 2000, however, California voters approved a $1.97 billion water quality initiative, which earmarked more than $250 million to improve management of the Delta. Part of the money will be used to control flooding and restore wetland habitat.

Freyberg points out that state and federal officials are working with wildlife and fisheries biologists, hydrologists, soil chemists and other environmental scientists to determine the best way to revive the fragile ecosystem. But that`s not always the case.

``Unfortunately, when it comes to California water policy, a lot of decisions get made that are not based on science,`` Freyberg says. ``So many constituencies are involved that tradeoffs are inevitable.``

Other speakers at the AAAS symposium will discuss how scientists are working to resolve the problems of water contamination, sedimentation and flooding in Silicon Valley, Lake Tahoe and other parts of Northern California.

Editors: Professor David L. Freyberg will participate in the symposium ``The role of science in the water issues of Northern California`` at the annual meeting of the American Association for the Advancement of Science on Tuesday, Feb. 20, from 8 to 11 a.m. PT at the Hilton San Francisco & Towers, 333 O`Farrell St., San Francisco, CA 94102. For more information, see the AAAS website at http://www.aaas.org/meetings.

Relevant Web URLs:
http://calfed.ca.gov
http://www.cfwc.com/
http://wwwdwr.water.ca.gov/

By Mark Shwartz

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