Colorado River (40668)
Colorado River Credit: mmisgen

LOS ANGELES, Calif. — Taking shorter showers won’t be enough to forestall a water shortage, as the state faces uncertainties related to declining fish habitats and a third year of dry weather in the Sierra Nevada, water officials said today.

To ensure there is enough water to go around, Southern Californians must make a concerted effort to cut back on water used in their yards, including growing drought resistant plants, reducing the frequency of lawn watering and keeping barrels to catch rain water, state and Metropolitan Water District officials said at an update on California’s water supply.

Lake Powell and Lake Mead, the two reservoirs that capture water from the drought-stricken Colorado River are less than half full, and water officials project a third year of dry conditions in the Sierra Nevada.

Water imported from the Colorado River and the Sierra Nevada — which together make up more than half of the Metropolitan Water District’s water supplies — has been threatened for years by drought and dry conditions, but officials said they are starting to see state reserves dip.

The reliability of the State Water Project, California’s water reserves, is being threatened by declining environmental conditions in the Sacramento-San Joaquin Delta, officials said. Even though the previous water year, which began Oct. 1, 2012, started wet, state regulation to protect the delta smelt — the little fish are protected by the Endangered Species Act — prevented the SWP from taking its share of water during that period.

After the wet season, the rain and snow stopped, leading to the driest January through June stretch on record and prompting state officials reduce SWP allocation to MWD by 35 percent.

The SWP’s low reserves in Lake Oroville — 350,000 acre feet less than last year — will likely lead to low allocations for MWD again in 2014, officials said.

“A wet winter could increase those projections, but we need to be cautious, given last year’s early rains gave way to record-dry conditions,” said state Department of Water Resources Director Mark Cowin.

Jeff Kightlinger, the MWD’s general manager, said they have no plans to impose mandatory water conservation restrictions on water users in the next year or two, but hopes that conservation measures will be taken up voluntarily so that water use stays the same even as the population grows.

“Southern California’s immediate supply outlook is stable, but the long-term picture is less certain, particularly in Northern California because of the Delta’s decline,” Kightlinger said.

He said restrictions on pumping in 2013 cost MWD the almost 300,000 acre-feet of water in 2013, the equivalent of the water used by 600,000 households.

Efforts are underway to restore the Sacramento-San Joaquin Delta habitat through the proposed Bay Delta Conservation Plan.

“We simply have to seize this once-in-a-generation opportunity to reverse the trends in the Delta that are not good for people or fish,” Cowin said.

Kightlinger said the MWD Board of Directors introduced more rebates on water conservation products, including for rain barrels, to contribute to a statewide goal to cut residential water use 20 percent per person by the year 2020.

The district supplies 26 cities and water agencies in Southern California, or 19 million people across six counties.