Timeline:

1990: Alabama files a federal suit against the U.S. Army Corps of Engineers to stop the corps from giving metro Atlanta more water from Lake Lanier. Alabama and Florida say Congress established only three purposes for the federal reservoir: to control floods, float barges downstream and generate power. Florida wants enough water to flow from Lanier into the Apalachicola Bay to provide a healthy environment for federally protected fish and mussel species, and to maintain its oyster harvest. Alabama wants enough water to maintain the operation of a nuclear power plant.

July 2009: U.S. District Judge Paul Magnuson rules that it is illegal for the Corps of Engineers to draw water from Lake Lanier to meet metro Atlanta’s needs. Magnuson says the corps can draw water for metro Atlanta at current levels for three years; after that, unless a political solution is reached either through negotiations with Alabama and Florida or through an act of Congress, the metro area will have to find water elsewhere.

April 2010: Georgia appeals Magnuson’s ruling.

June 2010: Gov. Sonny Perdue signs legislation designed to conserve water and help settle the dispute with Alabama and Florida. The new law bans nearly all outdoor watering from 10 a.m. to 4 p.m. and requires high-efficiency fixtures for all new construction after July 1, 2012.

January 2011: Gov. Nathan Deal sets aside $46 million in bonds to push new regional reservoirs. It is the first installment of a promised $300 million over four years for reservoir development.

March 2011: Three judges for the 11th U.S. Circuit Court of Appeals appeared inclined to settle the issue by sending the case back to the Army Corps of Engineers, which operates Buford Dam.

June 2011: The federal appeals court hands Georgia a victory in the tri-state water litigation.

February 2012: Florida and Alabama file petitions with the U.S. Supreme Court seeking review of the court decision that gave metro Atlanta rights to water from Lake Lanier.

June 2012: The U.S. Supreme Court declines to hear appeals from Alabama and Florida in the water wars case, solidifying metro Atlanta’s claim to water from Lake Lanier. The Army Corps of Engineers then determines it has the authority to grant Georgia’s request to draw water from Lanier to meet the state’s needs, but vows to conduct a thorough review before actually granting the request.

Georgia officials knew their fight wasn't over when they claimed victory in the long-running legal battle with Alabama and Florida over water rights. Now the next phase of the Neverending Water War is playing out in Congress rather than courtrooms.

A year after the U.S. Supreme Court cemented metro Atlanta’s claim to Lake Lanier’s water supply by letting stand a federal appeals court decision, lawmakers are considering legislation that could circumvent that and impact how millions of Atlanta residents get their drinking water.

The House is preparing this summer to consider a sweeping water bill, and some Florida and Alabama politicians want to insert changes that could make it harder for Atlanta to draw water from federal reservoirs. And Georgia, which only a few years ago pushed for congressional intervention, is warning other states not to interfere.

“It’s both bad precedent and bad policy to address interstate disputes in a Congressional water bill,” said Katherine Zitsch, the director of natural resources for the Atlanta Regional Commission. “If Congress were to get into this water dispute, they could be lured into at least a dozen others. It’s a Pandora’s Box that shouldn’t be opened.”

Brad Currey, who raises funds for the ACF Stakeholders, an influential regional water board, puts it a different way: “I don’t think this thing can be settled in Congress. That ought to be as obvious as the south end of a goat going north.”

The federal appeals court in 2011 reversed a ruling that said metro Atlanta had little legal right to water from Lanier, which supplies more than 3 million residents, and threatened to severely restrict access to the lake. The appeals court instead found that one of the purposes of the man-made reservoir was to supply water to Atlanta, and the U.S. Supreme Court declined to take up the case a year ago.

The U.S. Army Corps of Engineers is now fleshing out the finer details, namely how much water metro Atlanta can receive from Lanier, and how much water can be released downstream to support farms in South Georgia, power plants in Alabama and aquatic species in Florida.

The engineers are studying metro Atlanta’s request to withdraw up to 705 million gallons a day to meet the region’s needs through 2030 — far more than the roughly 360 million gallons the region now uses. The analysis includes hearings and assessments that could stretch to 2015, but some politicians in neighboring states want to bypass that process.

Florida Gov. Rick Scott is pushing for federal lawmakers to intervene, saying that the fishing industry on the Florida panhandle is “suffering an ecosystem and economic collapse” because of a lack of fresh water from Lake Lanier. He wants legislation “that allows adequate freshwater” to reach the Apalachicola region by blocking the Corps from allocating water to Atlanta without congressional approval.

Florida and Alabama senators attempted to put similar language into the Water Resources and Development Act last month, but Georgia Republicans Johnny Isakson and Saxby Chambliss fended them off by arguing that giving Congress more say over Corps water plans would have a nationwide ripple effect.

The U.S. House is set to consider the same legislation this summer, and the Georgia delegation is wary of the fact that six lawmakers from Florida sit on the Transportation and Infrastructure Committee — and no one on the committee is from Georgia.

One of those Floridians is Rep. Steve Southerland, a Republican whose panhandle district includes Apalachicola Bay, where the $200 million seafood industry has been in the midst of a sharp decline after recent drought conditions. He and other members of the Florida delegation argued in a letter that the Corps is overstepping its bounds by divvying up water from Lanier without "proper Congressional oversight."

U.S. Rep. Doug Collins, a Gainesville Republican, warned that requiring congressional approval of Lanier’s water could be a “poison pill” that could kill wide-ranging legislation that also deals with flood control, port planning and agricultural upgrades.

Collins and others are holding out hope that the governors from the three states will finally hash out an agreement, though there have been on-and-off negotiations since the 1980s and some involved see little chance of an imminent breakthrough.

Water wars veterans have learned to temper their expectations. Isakson remembers a conversation with then-Gov. Joe Frank Harris in 1990 about how close a water agreement seemed. Still, he said, last month’s “war games” in the Senate could help spur more conversations among the three governors to settle it on their own.

“This attempted circuitous backdoor approach that was used on WRDA, which we stopped, is not helpful on the one hand, but on the other hand I think it caused everybody to recognize how we’ve got to stop doing business like this,” Isakson said.

And the specter of a new legal battle looms, too. Fresh legal challenges from neighbors or advocates could force the fight back in the courtroom. The U.S. Supreme Court's on Thursday ruled in favor of Oklahoma in a water dispute with Texas, a decision that will be parsed by lawyers on all sides but appears to give deference to upstream states.

Some environmentalists and advocacy groups are pushing for broader talks. Gil Rogers of the Southern Environmental Law Center said there needs to be buy-in from the seafood industry, agriculture groups, utilities and other interests so the three states have “political ammunition” to strike an agreement.

That’s easier said than done. ACF Stakeholders Inc., a group representing those varied interests along Lanier’s river basin, has been trying to reach a consensus among its members for three years. But, with 56 participants, a broad-based agreement remains elusive.

“We’re not asking the question ‘Do you like this?’ or ‘Is this ideal?’ but ‘Can you live with it?’ And that will give us a place to start,” said Currey, a former RockTenn chief executive. “We all understand that nobody is going to get all they want.”

The impasse is part of the reason why Georgia is sticking to a strategy to spend $300 million over four years on water supply projects. Gov. Nathan Deal’s office said it will hold to that plan even if Georgia’s full request for Lake Lanier’s water is granted so it doesn’t have to worry about the whims of federal policy.

“I think all of us acknowledge that the secret to solving the water wars, in part at least, is being able to capture and store more water within the confines of the state of Georgia,” said Deal, who added that he’d like to jump-start negotiations with his counterparts “before we all get into election mode next year.”

Rogers said Georgia needs a more coherent water management plan to quench Atlanta’s thirst as it grows.

“The way that certainly Georgia is managing its water just seems … a little bit haphazard,” he said. “We have a dozen new reservoirs proposed around metro Atlanta, people wanting to tap into the Tennessee River. We just kind of seem to be all over the place right now.”