ATLANTA — Georgia's state and federal elected officials have yet to agree on how to work out a tri-state water deal, now that a federal judge has ruled illegal nearly all Georgia's withdrawals from a massive federal reservoir that has fed Atlanta's surging growth.

Gov. Sonny Perdue has said he will "fight to the death" to preserve Georgia's water rights, and added Thursday the state will pursue a "multi-pronged attack." But he suggested repeatedly that the solution lies with Congress, saying federal water rights are a national issue.

Federal lawmakers, meanwhile, have made it clear they prefer to let the governors of Alabama, Florida and Georgia hash out the details rather than risk allowing hundreds of legislators — many with little interest in the Southeastern water squabble — settle the issue.

U.S. District Court Judge Paul Magnuson last week gave the states three years to broker a deal or risk sharp cuts to Atlanta's water supply. That's not much time, considering that the three states have squabbled over water rights for nearly 20 years with little to show for it.

And the ruling against Georgia means the pressure is on Perdue to forge a deal before he leaves office in 2011.

Experts say they doubt the ruling — which even the judge called "draconian" — will ever shut the taps to the roughly 3 million metro Atlanta residents who rely on the Lake Lanier, the north Georgia reservoir that is the city's main water source. But it could be the catalyst that finally forces the three states to reach a pact.

The judge said the reservoir wasn't built to supply water, but to be a source of hydroelectric energy.

The governors of Alabama and Florida praised Magnuson's wisdom, and few dispute that the ruling weakens Georgia's bargaining position.

Negotiations could force Georgia to make significant concessions the state has long been unwilling to accept, such as establishing tighter water use restrictions and offering rebates for more efficient toilets, dishwashers and washing machines.

Perdue vowed to appeal and sought to present a united front.

"This is a Georgia issue," he said Thursday after a meeting with business and political leaders. "We'll deal with it with one voice and one movement."

He says Georgia's options include jump-starting negotiations, asking the U.S. Supreme Court to step in, pressing an appeal and evaluating other water resources such as tapping another section of the Chattahoochee River. The river feeds Lake Lanier and flows out of it through the Buford Dam.

The river, Perdue said, "is not a federally constructed program — that's God-constructed."

But the governor said Thursday that Congress will play a key role in any development. He said that's because the judge's ruling could set a precedent affecting other federal reservoirs that other states depend on for water.

Many of the delegation's leaders say they want the governors to work out the details of a plan before it's ratified in Washington.

"All the expertise is with the respective states," Sen. Saxby Chambliss, R-Ga., said after the delegation met Tuesday.

"Naturally it would be more desirable for them to at least make the initial decisions."

Metro Atlanta leaders have echoed that sentiment. Sam Olens, who chairs the Atlanta Regional Commission, said, "Everyone understands this issue is best left up to the three states — not a courtroom or the United States Congress."

Perdue has said he's willing to negotiate — as long as it doesn't threaten Georgia's water supply.

"I'm going to negotiate in the best interest of Georgia in the near term, in the intermediate term and the long term," he said.

"And the only deal breaker there is something that doesn't allow Georgia and the metro area to continue to prosper as it has in the foreseeable future."