California Has Given Out Rights To Five Times More Water Than It Actually Has

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According to a new study, the water rights given out by California amount to five times the amount of surface water the state’s ecosystem can actually provide.

The analysis, published Tuesday in the journal Environmental Research Letters, found that water rights issued since 1914 add up to 370 million acre-feet of water annually, while the surface water that actually flows through the state adds up to just 70 million acre-feet in a good year for precipitation. An acre-foot of water is roughly enough to supply two households for one year, and 300 million acre-feet of water is enough to fill Lake Tahoe two-and-a-half times over. The study arrived at its numbers by crunching public data from the State Water Resources Control Board, the state agency that administers the water rights.

The L.A. Times reported that 16 of California’s 20 major rivers face a rights allocation that exceeds the natural supply, including the San Joaquin River, the Kern River, and the Stanislaus River.


CREDIT: The L.A. Times

“It’s kind of like standing in line to get into a concert and they give you a ticket when they’re already at capacity,” Joshua Viers, a UC Merced professor and one of the study’s co-authors, told the Times. “But you don’t know that you’ll never actually get in to see the show.”

The result, according to the researchers, is a complicated and incoherent system that doesn’t know who has rights to what, when they’re making use of those rights, or how much water they’re taking. Residents will sometimes take water, then apply for the right to use it after the fact, then continue to take it while their application is pending — a situation that can continue for a decade. Others may deliberately overestimate their allocation so they don’t lose as much water when the state tries to enforce cutbacks. On top of all that, many irrigation districts and cities in California lay claim to enormous amounts of water issued under rights prior to 1914, which are not included in the State Water Resources Control Board’s data. That means the study likely underestimated the degree to which rights overshoot the supply, and the California government doesn’t even know who has what rights in many cases.

“Without supervision of distribution, appropriative water rights are meaningless: We do not have a coherent system for allocating water,” Michael Hanemann, a UC Berkeley professor of environmental and resource economics who was not part of the research team, told the Times.

The researchers said the State Water Resources Control Board needs a top-to-bottom overhaul of its procedures and policies, and that a better system would allow state regulators to do a better job targeting and coordinating cutbacks during times of drought. “All those allocations mean that in times of drought, it’s hard to tell who should have to reduce water use, causing delays in issuing curtailments,” Viers continued. “It’s a broken system, from a policy perspective.”

Unfortunately, the agency also lacks the legislative authority and the funding to make the changes.

As of the start of August, 58 percent of California was in “exceptional drought” as measured by the U.S. Drought Monitor — the most widespread drought levels of that severity the agency has ever recorded since its debut in 1999. Records that go back much further suggest the drought could be comparable to the landmark dry spell California endured in the 1970s, and even comparable to any event the state has seen since the mid-1800s. California also recently breached a 120-year-old record for heat, hitting an average of 4.6 degrees Fahrenheit warmer than normal for the first half of 2014.

When accounting not just for the state’s use of surface water, but for its use of groundwater reservoirs and other supplies as well, California is consuming several million acre-feet of water per year above and beyond what the ecological system can naturally replenish annually. It’s a problem that’s been growing steadily worse since the 1960s, according to research from the Natural Resources Defense Council (NRDC). But the study also found that a combination of practices — including more efficient irrigation methods, better plumbing and fixtures in homes, more water reuse, and better storm water capture, among other things — could close the gap between California’s water use and its available supply with plenty of room to spare.

“The good news is that the state is actively working to improve water-use reporting,” Ted Grantham, a UC Davis postdoctoral researcher, and the study’s other co-author, told the Merced Sun-Star. “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 also told the Sun-Star that they’re working in conjunction with state officials to repair some of the issues with the water rights database, and to make more of the information easily accessible to state lawmakers. Viers added that UC Merced “has positioned itself to become a real leader in water resources” by developing programs that could reshape California’s water use to better meet demand.

“We can’t manage what we don’t measure,” Viers said. “We’ve been putting a lot of efforts in developing intelligent infrastructure that will develop better information and lead to better decision-making.”