An ambitious statewide water plan that was adopted when the economy was soaring more than four years ago would be scaled back by one-third under a new 10-year plan to be considered today.

The new, $800 million-a-year CalFed finance plan is still massive and proposes to continue spending hundreds of millions each year on restoring ecosystems and using water more efficiently.

But with money running out on parks and water bonds that have paid for more than half of the program since 2000, the California Bay-Delta Authority is on course to deplete its funding in just two years.

"We're recognizing that we've got a funding crisis on our hands, and we'd better get on top of it," said Patrick Wright, who administers CalFed as the head of the Bay-Delta Authority.

The plan would slash by half the state's share of funding, from 60 percent to about 30 percent, and calls for the federal government to increase its share of the load from 7 percent to 21 percent. The remaining 49 percent of the funding would come from large water users, water agencies and local governments.

Wright said state lawmakers are highly unlikely to award the $240 million a year called for as the state's share of the plan, but he added that voters might be willing to approve new bonds every couple of years.

It also is uncertain whether the federal government will come up with its proposed $170 million-a-year share.

In October, Congress removed a sticking point that had prevented CalFed from receiving substantial federal funding, but whether lawmakers in Washington will follow through with real money is unclear.

"That's the intent of the plan, to push for more federal funds," Wright said.

The plan also lays out how much money must come from water users for various programs. For example, 30 percent of funding for ecosystem restoration will come from water users.

But details are sketchy on some future parts of CalFed, such as the financing considerations for building or expanding five reservoirs. Expanding Los Vaqueros reservoir in eastern Contra Costa County -- still just a possibility -- could be billed in part to the general public if it is determined those projects would provide public benefits, such as boosting fisheries.

When the CalFed program was approved in August 2000, it was touted as the most comprehensive water management program in the world and the most ambitious ecosystem restoration program ever attempted.

It was intended to end furious water wars that erupted in the early 1990s by stabilizing Delta water supplies, improving water quality, fixing Delta levees and restoring ecosystems.

Still, Greg Gartrell, assistant general manager of the Contra Costa Water District, said the funding plan now on the table provides relatively little money for water agencies and more for environmentally friendly programs like ecosystem restoration and water use efficiency.

"This is a huge, huge package," he said.