The judge even hinted that the entire dispute could be resolved as early as January.

Florida and Alabama have claimed that Georgia uses too much water from Lanier, leaving those two states with less water for economic and industrial uses. Florida also claims it needs more water from Lanier to support endangered mussels and sturgeon in the Apalachicola River.

The Georgia Environmental Protection Division has argued that releasing more water from Lanier would cause harm to Georgia, which is still mired in extreme drought.

Kevin Chambers, spokesman for EPD director Carol Couch, said Couch declined to comment Tuesday "because of litigation."

Val Perry, vice president of the Lake Lanier Association, said Magnuson’s decision is really about the sequencing of court cases.

"There are a bunch of lawsuits floating around, and he was going to address the (interim operating plan for Lanier) first," Perry said. "We (in the association) would have preferred that, because it’s about the situation we’re facing right now, with the lake level so low. But Florida asked him to consider water supply first, and he agreed with that."

Bert Brantley, spokesman for Georgia Gov. Sonny Perdue, said it seemed absurd to question whether Georgians have the right to drink water from Lake Lanier.

"After you’ve been using the water for so long, to come back and say this is not an authorized purpose is ridiculous," he said. "If we had just begun using Lake Lanier for water three weeks ago, this argument would make more sense."

But Brantley said the governor welcomed Magnuson’s ruling as "good news."

He said the judge had agreed to look at all aspects of Lanier as a water supply source, and not just at the specific points that were addressed in the earlier district court ruling. Brantley sees that as a win for Georgia.

"We believe in our position, and we’re confident that we’ll carry the day," he said.

Perry said no one realistically believes that Magnuson could shut off the water faucets for all of metro Atlanta.

"There’s no way that we’re going to lose water supply as an authorized purpose," he said. "That’s not going to happen."

The February appeals court ruling said that Lanier originally was built mainly for hydropower, and that Georgia and the U.S. Army Corps of Engineers would have to get approval from Congress if they want to change the way the lake is operated.

Magnuson said Tuesday that the appeals court ruling will play a role in his ultimate decision on the lake’s future, even as an attorney for the state of Georgia vowed to appeal the case to the U.S. Supreme Court.

But what would happen if Magnuson ruled that Georgia has no right to withdraw water from Lanier?

The 38,000-acre lake serves the water needs of more than 3 million people in the metro Atlanta area, including Gainesville.

Kelly Randall, director of Gainesville Public Utilities, said there simply is no other water source that most people in the region can turn to.

"But that’s not the issue," he said. "It’s whether the original intent of the lake was for water supply. There’s a lot of arguments that it was an authorized use, and there’s a lot of arguments that it wasn’t."

Randall points out that Magnuson will rule about whether Georgia has the legal right to take Lanier’s water, but the judge is not expected to take any action if Georgia is in fact violating federal law.

"It’s not about the fix," Randall said. "(Magnuson’s ruling) is neither good nor bad. It is what it is. But at least the judge made a decision about something. That’s a sign of progress."