California is deficit-spending its water and has been doing so for a century, according to new research from the University of California.
Joshua Viers, UC Merced professor of water resources, teamed with Ted Grantham, a UC Davis postdoctoral researcher at the time, to look into the state’s database of water-rights allocation dating back to 1914.
The researchers found that distribution exceeded water supply by five times the average annual runoff and 100 times the actual surface-water supply for some river basins.
The state has about 70 million acre-feet of surface water available for use in a good year, but water rights issued since 1914 allocate a total of 370 million acre-feet, researchers reported. An acre-foot is the amount of water it would take to cover one acre to a depth of 1 foot.
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Viers and Grantham’s study “100 years of California’s Water Rights System: Patterns, Trends and Uncertainty” was published in the journal Environmental Research Letters on Tuesday. The research analyzed public data from the State Water Resources Control Board, which administers water rights.
According to Viers, the water-rights allocation system is complicated and backlogged, which contributes to the problem. “It’s a broken system, from a policy perspective,” he said. “What’s on the books shows an overwhelming disparity between resource availability and appropriation.”
Another factor is that with California’s Mediterranean climate means it’s almost impossible to be certain how much water will be available in any given year. Considering California is in a drought year, researchers are advocating that policies and procedures be updated.
“The good news is that the state is actively working to improve water-use reporting,” Grantham said. “And given the public’s current attention on drought and California water, we now have an unprecedented opportunity for reforming the water-rights system.”
Viers and Grantham are working with the state on sorting out some of the issues in its database to get more information and make it available to policymakers.
Supported by the Center for Information Technology Research in the Interest of Society and the National Science Foundation, UC Merced professor Roger Bales and colleagues developed a sensor network that could be turned into a unified, statewide water-information system. However, Bales estimates such a system would cost about $100 million.
UC Merced researchers have also developed programs that could help meet the demands for adequate water supplies, Viers said. “UC Merced has positioned itself to become a real leader in water resources.”
“We can’t manage what we don’t measure,” he said. “We’ve been putting a lot of efforts in developing intelligent infrastructure that will develop better information and lead to better decision-making.”