WASHINGTON - Rep. Dan Lungren, R-Gold River, said Thursday that it is time to look seriously at restoring Hetch Hetchy Valley in Yosemite National Park by draining the reservoir that has been a source of clean water for San Francisco for more than 80 years.

The conservative Republican and former California attorney general said he is convinced that the 300-foot-deep reservoir could be drained without costing San Francisco its water supply, and that doing so would add a spectacular companion to Yosemite Valley in the internationally treasured park.

"Where else could we produce that?" Lungren said in an interview. "Where else in the United States would we be able to give that to our children and our grandchildren?"

Lungren's endorsement of the Hetch Hetchy restoration comes as Congress is beginning to consider President Bush's 2008 budget submission, which includes $7 million for the Interior Department to study the idea.

That budget item has drawn scorn from California Republicans and Democrats.

Lungren's endorsement makes him the first member of Congress to side with environmentalists backing the restoration project.

"It's a breakthrough," said Ron Good, head of Restore Hetch Hetchy. "We are very pleased that Representative Lungren has taken an interest in this."

Completely unenthused was Sen. Dianne Feinstein, San Francisco's former mayor and a senior Democrat on the Senate Appropriations Committee.

As chair of the committee's key subcommittee funding the Interior Department, Feinstein has the power to single-handedly block the study money.

"I will not support efforts to eliminate this precious resource," she said in a statement Thursday.

Lungren acknowledged that he has some powerful opponents, who he assumes include House Speaker Nancy Pelosi, D-San Francisco. Pelosi's office did not respond with a comment.

"It's tough sledding," Lungren said.

"But we need to show people that this is not a silly pipe dream that radical environmentalists support," he said.

"I've never been accused of being a radical environmentalist."

There may also be some political mischief behind Lungren's endorsement. He is a strong advocate of constructing a multipurpose dam on the American River at Auburn.

Many who oppose draining Hetch Hetchy, including Feinstein, also oppose construction of an Auburn dam. But the arguments for Auburn -- the need for water storage as global warming worsens the forecast for rain and snowfall in the Sierra, and the valuable production of clean hydropower -- are also the reasons typically cited for opposing drainage of Hetch Hetchy.

Lungren insisted his motives are pure, saying that he met his wife, Bobbi, in Yosemite when they were in college and it's always been a favored place for them.

"I am not doing this to go after them or to stick a finger in their eye," Lungren said of the Auburn critics.

Hetch Hetchy has been a primary source of clean mountain water for San Francisco since the O'Shaughnessy Dam was completed in 1923, damming the Tuolumne River.

A state study last year concluded that the 380,000 acre-foot reservoir could be drained and the valley restored at a cost of between $3 billion and $10 billion, much of that for water filtration and power replacement.

Within hours of the posting of a story on Lungren's announcement on The Bee's Web site Thursday morning, the Bay Area Council, representing more than 275 of the largest employers in the area, issued a statement calling on Lungren to reconsider.

"Wiping out the hyper-pure water source for one-third of the Bay Area at a cost of $10 billion, all to increase access and use of a valley already visited by 50,000 tourists per year, just doesn't make sense," said the group's president, Jim Wunderman.

But Lungren said Yosemite is one of the most crowded parks in the country and that it's been national policy for years to restore them to their natural condition by moving tourist facilities and other such structures outside park boundaries.

"Not all valleys are created equal, not all dams are created equal and not all reservoirs are created equal," he said.