Days after a judge issued a ruling that could create Southern California's worst water shortages since the last great drought in 1991, the region's main water supplier said it was racing to create an emergency plan to divvy up water if rationing is necessary in 2008.

Officials from the Los Angeles-based Metropolitan Water District said Tuesday that they hope to complete an emergency plan by November.

Metropolitan Assistant Manager Roger Patterson said the agency hadn't created such a plan up to now because it has always had enough water to comfortably sustain nearly 18 million Southern Californians in six counties - including San Diego and Riverside.

That could change in 2008.

Late Friday, U.S. District Court Judge Oliver Wanger issued an unprecedented ruling that would curtail pumping water from Northern California to the rest of the state through the fragile Sacramento-San Joaquin bay delta to protect an endangered fish, the delta smelt.

Metropolitan officials said Friday that they were still deciphering Wanger's ruling. But state officials and Metropolitan said Southern California could lose between 14 percent and 30 percent of the Northern California water that made up two-thirds of the region's supply this year.

"This is the first time since 1991 where we're saying we better have an allocation plan in place," Patterson said of the plan that would dole out potential water cuts to cities and counties. "So in the event we need to use it, it's there and ready."

Wanger issued a verbal ruling Friday and is not expected to file a written order until late October. That timetable has made it difficult for state, federal and regional water agencies to calculate the exact reductions the pumping cutbacks could cause.

Metropolitan officials said it was too soon to predict whether the agency would issue mandatory water cuts that could trickle down to the public next year.

Once Metropolitan completes an emergency plan to divide its water, the agency's board - composed of representatives from all the agencies that buy Metropolitan's water - will have to wait to see how the state cuts supplies from Northern California. Then the board will decide whether to issue mandatory rationing, Patterson said.

Patterson said Metropolitan sells about 2.25 million acre-feet of water each year to agencies in six counties that deliver to nearly 18 million residents. He said Metropolitan has roughly the same amount stored away in reservoirs and groundwater banks, meaning the agency could comfortably use its storage to make up the difference in lost Northern California water in 2008.

However, water officials said they worry that the court ruling could create years of cutbacks of the region's Northern California supply, and that it might be smarter to issue some mandatory cuts to the region's supply in 2008. That would leave stored water to ease shortages in 2009 and beyond.

Meanwhile, water officials from Southwest Riverside and San Diego counties Tuesday continued to react to the court's ruling with emotions ranging from anger to worry.

All of them said the state's water supply situation was the shakiest they could remember and urged people statewide to start figuring out ways to cut water use.

"We're very concerned about the ruling, and it's still unclear exactly what the impact is," said Brian Brady, general manager of Southwest Riverside's Rancho California Water District.

Other Riverside officials said their boards could start weighing the idea of using punitive rate fines to enforce potential cuts.

In the past, Southern California's water-supply woes could be reversed with a little help from Mother Nature in the form of rain and snow.

For example, in 1991, Southern California residents were facing major water cuts because of a brutal drought that ran from 1987 through 1991. However, just as San Diego County Water Authority board members were about to administer 50 percent cuts, the skies began to pour down rain in what is remembered as the "March Miracle."

But officials say rain and better snowpacks may not help much now. Rain would recharge local reservoirs and groundwater supplies. But the court order to curtail pumping in the bay delta would remain in effect to protect the delta smelt. That would mean state water officials would not have enough time to ship Southern California all of its water.

Gary Arant, longtime Valley Center Municipal Water District general manager and a Water Authority board member, said the looming shortages could have been avoided.

Arant said water leaders statewide have known for decades that California needed to build more storage, and a "peripheral canal" that could move Northern California water around the bay delta, but legislators and voters had ignored the need.

California voters roundly defeated a peripheral canal plan in the 1980s.

"This is poised to have devastating impact on the state's economy," Arant said. "And it didn't have to happen. Like the power crisis, it didn't have to be this way."

- Contact staff writer Gig Conaughton at (760) 739-6696 or gconaughton@nctimes.com.

On the Net:

For information about how to 'painlessly' cut back water use, go to:

http://www.sdcwa.org

Http://www.bewaterwise.com