CARROLLTON — Alabama and Florida asked the U.S. Supreme Court on Monday to decide a long-running feud with Georgia over how much water metro Atlanta can take from a reservoir that provides local drinking water for the sprawling city while also fueling a river system that supports wildlife and jobs in three states.

Lawyers representing Georgia's neighbors asked the high court to strike down a 11th U.S. Circuit Court of Appeals ruling that found that metro Atlanta had the right to tap Lake Lanier on the Chattahoochee River for drinking water. That reservoir is the main water source for about 3 million people in metro Atlanta.

The appeals court ruling was a major blow to Alabama and Florida, who say that Congress never intended that the federally funded reservoir would provide local drinking water. They accuse metro Atlanta of using so much water upstream that it threatens the water supply for factories, endangered species and the mussel fishery downstream. The issue also causes splits in Georgia, where farmers — the state's largest economic sector is agriculture — worry that metro Atlanta's consumption cuts into their water for irrigation.

"In terms of dollars and cents, the Eleventh Circuit's ruling has the potential to shift the need for billions of dollars of infrastructure expenditures from the Atlanta region to downstream communities, including those in Alabama and Florida," lawyers for Alabama said.

Georgia Gov. Nathan Deal declined through his spokesman to comment on the Supreme Court appeal. Deal earlier called for an end to litigation and a negotiated settlement among the states.

The water dispute has simmered since 1990. In 2009, U.S. District Court Judge Paul Magnuson sided with Florida and Alabama. He ruled that metro Atlanta had little legal authority to draw water from Lake Lanier. He also set a July 2012 deadline for the political leaders of all three states to reach a deal resolving their dispute over water rights.

If a deal were not reached, Magnuson said, he planned to restrict water withdrawals from Lake Lanier to levels last seen in the 1970s, when metro Atlanta was a fraction of its current size.