It is interesting therefore to see how the current US drought is playing out politically.
Environmentally, it appears that by law a certain amount of water must be released from Lake Lanier "to protect mussels, sturgeon and other species in the Florida Panhandle". This is where the debate between economics, water quality and nature gets a little murkier.
Drought in Southeast US Leads to Spat Over Lake [Planet Ark]
LAKE LANIER, Ga. - A large, man-made lake in north Georgia is at the center of a political storm over how to distribute water resources between three US states in the face of the region's worst drought in decades.
Lake Lanier stands near the head of a watershed that feeds the booming city of Atlanta about 45 miles (72 km) to the south, leading to accusations that the city is consuming more than its fair share of water.
Also relying on the lake are other towns, industries and power plants in parts of Georgia, Alabama and Florida before the water drains south into the Gulf of Mexico.
More than a year of low rainfall has reduced the lake's water level by about 14 feet (4.3 meters) from its seasonal norm and the situation is worse in lakes farther south, according to the US Army Corps of Engineers. Atlanta has had 23.5 inches of rain this year compared to 39.1 inches in a normal year.
Experts dismiss as alarmist headlines predicting that Lanier could run dry in 90 days but the drought has reignited two-decade-old tensions over access to water.
Georgia's governor, Sonny Perdue, declared an emergency in parts of the state, imposed water restrictions and appealed to Washington for help for people hit by the shortage.
He also filed a federal lawsuit bid to force the Corps, which manages Lake Lanier, to reduce the amount of water it sends downstream each day.
Florida Gov. Charlie Crist strongly opposed the suit, arguing that the US$200 million commercial fishing industry in Florida's northwestern Panhandle region already was threatened by reduced flows from Georgia.
Alabama Gov. Bob Riley said any reduction in flows from Lake Lanier would hinder cooling at the Farley nuclear plant in southeastern Alabama, jeopardizing electricity to 800,000 households across all three states.
For most of its 7.5 million annual visitors, Lake Lanier is a pleasure park close enough to Atlanta to provide a getaway from city life with nearly 700 miles (1,120 km) of shoreline and 10,000 private boat docks. Now, the sight of stranded docks sticking out of the mud is the most visible symbol of the drought.
Buford Dam, a vast concrete structure hidden behind a wall of grass at the lake's southern end, is a symbol of the political battle the drought has set off.
By law the dam must release at least 650 cubic feet (18 cubic meters) per second of water downstream to ensure water quality and, crucially, to supply other rivers and lakes, said Jonathan Davis, the Corps' operations project manager at the lake.
Given that water flowing into the lake from the Chattahoochee and Chestatee rivers is down by more than half, one might expect the outflow to be similarly reduced.
But water in the total river basin stands at 35 percent of normal and Davis said the Corps has been sending up to 3,000 cubic feet (85 cubic meters) of water per second cascading south, raising water levels and churning the river.
In part, the Corps is responding to the demands of the Endangered Species Act, which stipulates a minimum outflow from the lake to protect mussels, sturgeon and other species in the Florida Panhandle.
But beyond that some scientists argue that the region's over-reliance on Lake Lanier is flawed.
"It's scientifically unsound to expect Lake Lanier to support the entire ... watershed as the Army Corp of Engineers is doing," said David Stooksbury, Georgia's state climatologist.
"They are artificially keeping the (Chattahoochee) river much higher than it would be if those (downstream) lakes were not there."
Atlanta, like US cities such as Phoenix, Dallas and Denver, has experienced rapid growth without being based around a major water source, Stooksbury said.
For the region that depends in part on Lanier for water the situation is exacerbated because Atlanta, which has more than quadrupled in size since Lanier was built 50 years ago and is the largest city in the region, also happens to stand near the headwaters.
Ronald Payne, deputy commander of the Mobile district in Alabama for the Corps, said over-consumption did not play a significant part in creating the resource problem.
But Adam Snyder, executive director of Conservation Alabama, said poor water management planning -- as much as low rainfall -- was at the root of the dispute.
"The problem is that you have a high demand for water in the Atlanta area," he said. "They being at the headwaters of so many different streams and everyone else is at their mercy .... It is three states versus the Atlanta metropolitan area.
"Forty years ago Atlanta claimed they were 'too busy to hate,'" he said, referring to the city's slogan as a racially harmonious city. "Since then they have been too busy to plan and the rest of us are suffering as a result."