Democratic gubernatorial candidate Roy Barnes said Wednesday he would be ready to ask a federal judge for more time to work out a long-standing water dispute between Georgia, Alabama and Florida.

He said he was concerned the three states couldn't meet a 2012 deadline on water-sharing and a mediator might be needed in the mix.

Barnes spoke on the matter after a news conference off the Chattahoochee River, after accepting the endorsement of Georgia Conservation Voters. He also unveiled a plan to make water planning and conservation a priority as governor.

"If we're going to provide economic opportunity and improved quality of life for Georgia's businesses and citizens, we've got to work towards solutions and solve our ongoing water crisis," he said.

Judge Paul Magnuson ruled in July 2009 that Lake Lanier should not be used as a municipal water tap and that area governments had three years to either seek congressional approval or work out a solution with Florida and Alabama.

If neither could be achieved, metro Atlanta governments could no longer use Lanier for drinking water and Gainesville could only tap into it at 1970s levels.

"The deadline poses problems, we've known that all along," said Brian Robinson, spokesman for Republican nominee Nathan Deal, in response to Barnes' comments.

"Basically Nathan's water plan is to negotiate in good faith with the two new governors of Florida and Alabama. We have a clean slate; we can get off to a good start and hopefully find some common ground."

Robinson added, "We've already seen some progress on the court level because the court ruled this year that the other states can't use the endangered species act as a negotiating tool against us. They were doing that to keep flows at a certain level down there at the Apalachicola Bay."

Georgia has asked a federal appeals panel to overturn Magnuson's ruling, asserting the judge misinterpreted laws governing who can take water from Lake Lanier. Gainesville is one of the Georgia appellants.

Val Perry, executive vice president of the Gainesville-based Lake Lanier Association, said he believes asking Magnuson for an extension of the ruling might be needed at some point.

But he doesn't think talks between the states should end too soon.

"We're going to have new governors in January. ... Before we give up, 18 months before the deadline, I think we should make sure that those new governors understand the issues and find a way to get this done," Perry said.

The U.S. Army Corps of Engineers, which manages Lake Lanier, "won't do anything ... unless Congress tells them too, and Congress won't vote on anything until there's some meeting of the minds of the governors," he added.

Sally Bethea, executive director of Upper Chattahoochee Riverkeeper, said she believes elected officials better heed Magnuson's ruling to the letter.

"Given what we've heard to date from (him), he intends to see this thing done by 2012," she said.

"I don't think banking on any extensions would be a prudent thing to do. I think this is a judge who is a bit puzzled why there hasn't more progress made to date.

"I believe everybody involved needs to assume that this is a hard deadline and all three states have got to show a willingness to try to come to some sort of an arrangement."

Staff writer Melissa Weinman contributed to this report.