By BEN EVANS

Associated Press

WASHINGTON -- Sixty years ago, the late Atlanta Mayor William Hartsfield resisted helping to pay for Lake Lanier, a new federal reservoir being built north of town. Atlanta had plenty of water, he wrote Congress. Thanks, but no thanks.

Those words came back to haunt Atlanta last year. A federal judge ruled the city illegally has been tapping Lanier for years as its primary water source. Unless Congress reclassifies the lake as a water supply, the judge ruled, Atlanta will be cut off by 2012.

The question now is how many other cities might be in the same boat, according to experts interviewed by the Associated Press. The U.S. Army Corps of Engineers, which sells water from 135 federal reservoirs throughout the country, recently gave Congress a preliminary list of 40 projects in 14 states that initially were not authorized for supplying water but are being used for that purpose.

Georgia leaders are trying to rally other states as allies in pursuing new classification from Congress for all the Army Corps' lakes. But the effort isn't gaining much traction. Many city leaders have a hard time envisioning water shortages -- just as Hartsfield did in 1948.

"I think the people around here would come unglued if the government came in and said we don't have an authorization to use Lake Winnebago after we've been using it for close to 40 years," said Mayor Tim Hanna of Appleton, Wis.

At least 500,000 people in various eastern Wisconsin communities rely on Winnebago for water, even though the corps has said its use is not authorized.

In southern Kentucky, tens of thousands of people rely on water from Laurel River Lake, which originally was built for hydropower and recreation.

"We don't have any contingency plans," said Randy Bingham, the superintendent of the London Utility Commission in southern Kentucky, which supplies water from the lake to about 12,000 people.

The Atlanta case, which was brought by Florida and Alabama in a 20-year feud over river rights, highlights a long-simmering struggle to reconcile the original intent of the reservoirs with modern demands for water. With water supply traditionally a local responsibility, the federal lakes mostly were built after World War II to generate hydropower or ease river navigation.

Only after rapid population growth has the corps -- frequently under pressure from politicians -- increasingly turned to water supply. The shift often has come on shaky legal ground, as U.S. District Court Judge Paul Magnuson found with Lake Lanier.

In his ruling, Magnuson noted Congress listed water supply as an "incidental" use of the lake, thanks largely to resistance from Hartsfield and other Atlanta leaders. As a result, he found, the corps has been breaking the law by selling nearly a quarter of the lake's capacity to Atlanta.

Lanier now serves about 3 million people, but Magnuson said the spigot mostly will be cut off in three years if Georgia can't push a settlement through Congress -- a daunting task given fierce resistance from Florida and Alabama, who rely on strong river flows downstream for their own industries.

"The court recognizes that this is a draconian result," Magnuson's ruling said. "It is, however, the only result that recognizes how far the operation of (the project) has strayed from the original authorization."

It's unclear just how many reservoirs have similarly strayed. The corps, which maintains it is operating the lakes legally, has authority to divert excess capacity in a reservoir even when water supply wasn't an initial purpose. The question is whether the corps is stretching the law to satisfy all the demands -- as Magnuson found in the Lanier case.

"It's definitely a precedent," said Cynthia Drew, a water-law professor at the University of Miami Law School. "If your city is relying on a (federal) project for water supply, it would be a very good decision to check and make sure that the project is really authorized for that purpose."

George Sherk, water-law professor at Colorado School of Mines, said such practices are rampant, and he said the Atlanta ruling could set off a wave of new legal challenges. That's especially true with demands on water supplies growing and river systems becoming increasingly strained.

"The interesting thing is whether the next round of these go to trial or are settled more easily," Sherk said. "The facts should not make these hard cases. The corps either is or isn't operating within its statutory mandate."

If not, many communities might be in store for an unpleasant surprise.

Bingham said Kentucky tends to have an abundance of water. "I was just hoping we were hidden in the hills of Kentucky and no one would think about us," he said.

A look at reservoirs used for water supply

WASHINGTON (AP) -- A list of federal reservoirs by state that were not initially authorized for water supply but are now being used for that purpose:

Arkansas -- Lake Ouachita, DeGray Lake, Blue Mountain Lake, Bull Shoals Lake, Greers Ferry Lake, Nimrod Lake, Norfork Lake

Georgia -- Carters Dam and Lake, Allatoona Lake

Georgia/South Carolina -- Hartwell Dam and Lake, Richard B. Russell Lake

Iowa -- Rathburn Lake

Kansas -- Kanopolis Lake, Melvern Lake, Milford Lake, Perry Lake, Pomona Lake, Tuttle Creek Lake

Kentucky -- Grayson Lake, Carr Creek Lake, Cave Run Lake, Green River Lake, Rough River Lake, Laurel River Lake

Kentucky/Tennessee -- Center Hill Lake, Dale Hollow Lake

Missouri -- Harry S. Truman Lake, Stockton Lake

Mississippi -- Enid Lake

Ohio -- Paint Creek Lake

Pennsylvania -- Youghiogheny Lake

Tennessee -- J. Percy Priest Dam and Reservoir

Texas -- Granger Dam and Lake, O.C. Fisher Dam and Lake, Proctor Lake, Somerville Lake, Stillhouse Hollow Lake, Waco Lake

Virginia -- John H. Kerr Dam and Reservoir

West Virginia -- Summersville Lake

Source: U.S. Army Corps of Engineers