Published Dec. 23, 2010
Although a water dispute between North and South Carolina has been settled, this may only be the beginning for Southeastern states.
Researchers studying freshwater sustainability in the United States have found that the Southeast, with the exception of Florida, does not have enough water capacity to meet its future needs.
“For more than a century, the Southwest has been the focus of long-running legal disputes over water resources, but the Southeast is now becoming a more contentious region for water use,” said Will Graf, a geographer in the University of South Carolina’s College of Arts and Sciences.
Graf said that 25 years ago, journalist Marc Reisner wrote Cadillac Desert: The American West and Its Disappearing Water, which predicted that water resources would be unable to support the growing demand of cities, agriculture and industry in the Southwest.
A paper co-written by Graf featured in this month’s journal Proceedings of the National Academy of Sciences supports most of Reisner’s conclusions, using data and methods unavailable to Reisner in 1986.
Although the paper focuses on freshwater sustainability in the Southwest, Graf and co-authors Tushar Sinha, an engineer at North Carolina State University, and John Kominoski, an ecologist at the University of Georgia, said the findings have important implications for the Southeast as well.
“It turns out that the Southeast has a relatively small margin of water surplus for the future,” Graf said.
The water resource picture in the Southeast is becoming similar to that of the Southwest, where water disputes have long been a prominent part of policy and resource management, Graf said.
“Who would have guessed that instead of Arizona vs. California, we may have South Carolina vs. Georgia?” Graf said. “The looming issue of providing enough water for Atlanta and the possibility of reaching to the Savannah River for water for Atlanta is an example of the coming debates over our region’s water.”
The researchers found that neither the Southwest nor the Southeast has enough water to meet its needs.
Although there are more reservoirs in the East, they are smaller than their Western counterparts, Graf said. These smaller reservoirs are more susceptible to evaporation than larger ones. Most of the smaller reservoirs in the Southeast are designed to capture precipitation that falls within a year, so changes in precipitation rapidly influence reservoir water levels.
“The recent droughts in the Southeast during the summers of 2002, 2005 and 2007 indicate severe water shortages due to very low rainfall, and water supply is dependent upon precipitation, which is likely to be more uncertain in the near future,” Sinha said.
The authors cautioned that the paper’s estimates are conservative and are based on data from 1950-99. They do not include the previous decade, which had some of the highest temperatures and most extreme droughts, along with population increases.
“Also, the estimates don’t take climate change into account,” Kominoski said. “We expect to have less precipitation in the summer, during the growing season, and more severe droughts. As population grows, so does demand for water.”