U.S. District Court Judge Paul Magnuson said Lake Lanier wasn't built for water supply and the state's withdrawals are illegal. He acknowledged it would be impossible to immediately stop using the lake because it is metro Atlanta's main water supply for 4 million people. But he said if the state can't get permission from Congress within three years, the withdrawals must end.
"The Court recognizes that this is a draconian result," Magnuson wrote. "It is, however, the only result that recognizes how far the operation of the (lake) has strayed from the original authorization."
Alabama Gov. Bob Riley said the ruling would have a tremendous impact on his state's economic future.
"Atlanta has based its growth on the idea that it could take whatever water it wanted whenever it wanted it, and that the downstream states would simply have to make do with less," Riley said. "Following the Court's ruling today, this massive illegal water grab will be coming to an end."
The case involves a 2003 water-sharing agreement with the Army Corps of Engineers that would have allowed Georgia to take far more water from Lanier for its drinking supply over the coming decades. The deal would have allowed Georgia's withdrawals to jump from about 13 percent of the lake's capacity to about 22 percent.
Florida and Alabama contested the pact, saying the lake was initially built for hydropower and providing water to Georgia was not an authorized use.
Magnuson cited a lengthy historical record of testimony before Congress and Corps of Engineers documents to establish that serving Atlanta's water needs was only an incidental purpose for the lake. He noted that Georgia officials argued as much to avoid having to pay for part of the project when the reservoir was built in the 1950s.
Without congressional approval, the judge said the lake would return to 1970s levels, with only the cities of Gainesville and Buford allowed to take water. Others who get withdrawals just downstream from the reservoir would also see their water supplies drastically reduced.
The ruling could drive the states' governors back to the negotiating table with Georgia in a weakened position after a series of talks failed to yield a compromise in recent years.