PD Editorial: Planning for California’s water future

California’s drought response is spilling into unprecedented territory.

On June 20, the state Water Resources Control suspended nearly iron-clad diversion rights for about 115 individuals and public agencies, including Chico and several other small cities, that draw water from the Sacramento River, the San Joaquin River or the Delta. Among them, they hold rights to 1.2 million acre-feet - enough water to supply Los Angeles’ needs for two years.

This is the first curtailment of pre-1914 water rights in almost 40 years, and - assuming it withstands legal challenges - it’s the farthest reaching cutback ever.

But that may not be the case for long. As they explained the order, which addresses water rights dating to 1903, state officials warned that further restrictions are likely this summer, potentially affecting rights dating to the Gold Rush era as well as Hetch Hetchy reservoir, San Francisco’s primary water source.

These are crisis-driven decisions to address the immediate impacts of a punishing drought that’s now in its fourth year.

That’s true also of an order mandating a 25 percent cut in household water use that took effect June 1, restrictions already in place on junior water rights and reduced deliveries to state and federal water customers in the Central Valley.

As we noted in this space about three weeks ago, the El Niño effect - rising ocean temperatures in the equatorial Pacific - offers some hope that drought-busting winter storms will wash away most, perhaps all, of the emergency restrictions on city dwellers and farmers alike.

Even if that happens, state water officials need to address a chronic imbalance between supply and the needs of a population that’s projected to swell to 50 million by the middle of the 21st century. It won’t be easy.

Senior water rights holders already are lining up at the courthouse to fight the June 20 order, but as UC research shows, California has handed out rights to 370 million acre-feet of water - about five times more surface water than the state’s rivers produce in an average year. Sustaining that imbalance will only get more difficult as demand increases. The time to address it is now.

As for groundwater usage, well that’s anyone’s guess. California is only beginning to assess how much water gets pumped from underground aquifers each year. And the state’s first foray, a law passed last year, puts off any serious decision-making for decades.

However, the effects of over-pumping are increasingly obvious.

Last summer, as Nathan Halverson of the Center for Investigative Reporting detailed recently, scientists recorded the worst subsidence - ground sinking as a result of water being pumped to the surface - in at least 50 years. That record is likely to be short-lived, as the pace is expected to accelerate this summer.

Ripple effects include damage to highways, bridges and irrigation canals. The cost to repair public infrastructure damaged by subsidence hasn’t been tallied, but it will add up to tens of millions of dollars.

Subsidence is most obvious in the Central Valley, where some areas are sinking more than a foot a year as underground pockets have collapsed after water is pumped out. In coastal areas, including the Sonoma Valley, the threats from over-pumping include saltwater intrusion and undermining threatened fisheries.

There will be political and legal battles over any changes to California’s system of allocating water. Even a new rule requiring reporting of groundwater use in the Russian River watershed created a stir. But it’s increasingly clear that a system designed for a 19th century economy is outdated. And just as state officials have taken unprecedented steps to address the drought, they must break from the past to reshape water policy for California’s future.