SC attorney general: More water wars ahead

"This is the kind of thing we're going to be seeing from now on," McMaster told about 300 people at the South Carolina Water Resources Conference. "It won't be long before Atlanta tries to build a pipeline to the Savannah River."

Much of the drought-stricken Southeast has been wrangling over water. Tennessee and South Carolina worry Atlanta may look to the nearby Tennessee or Savannah rivers for relief. Meanwhile, Georgia, Alabama and Florida have fought over how much water can be stored in north Georgia lakes.

McMaster sued North Carolina last year after the state decided to allow 10 million gallons of water a day be diverted from the Catawba River, which flows into South Carolina.

"North Carolina simply can't do that to us," McMaster said. "A river flowing through one state into another state doesn't belong to the upstream state only."

He said the suit is rare because the U.S. Supreme Court agreed to directly take up the issue.

"The case will be a precedent, not only for the rest of the country, but for our dealings with the state of Georgia," McMaster said.

McMaster originally expected a decision by 2010, but said it will take longer after the city of Charlotte, Duke Energy and a water system serving Union County, N.C., and Lancaster County, S.C., were allowed to enter the case earlier this year.

There have been water disputes in the West for decades, but such conflicts are relatively new to the East, McMaster said.

"It's a different kind of law west of the Mississippi," he said. "Here we have riparian rights. When a river comes down, everyone has an equal right to it--maybe not an equal amount, but an equal right. Out West there is a different flavor to it and that is whoever got there first has an edge on the others."