Drought in the Southeast: Lessons for Water Management
Manuel, John, Environmental Health Perspectives
Long spared the persistent droughts that have plagued the western United States this century, the Southeast suddenly finds itself the most rain-starved region of the country. In the face of this threat, policy makers and utility companies are struggling to identify sensible, sustainable options for managing the region's water. Although there currently is no immediate public health threat posed by the Southeastern drought, it does point to a very real situation in regions around the world that struggle to maintain an adequate supply of potable water.
According to the Intergovernmental Panel on Climate Change report Climate Change 2007: The Physical Science Basis, as global temperatures increase due to rising atmospheric concentrations of carbon dioxide, so does evaporation. That, combined with cyclical drought, could pose dire threats to water supplies. By one model, published in volume 78, issue 5 (2006) of the Journal of Hydrometeorology, if global warming-related precipitation changes continue apace, the percentage of the Earth's surface in severe drought could rise from the current 3% to 30% by 2100.
The Southeastern drought has already had serious economic consequences, according to the National Drought Mitigation Center at the University of Nebraska, which estimates in its Winter 2008 DroughtScape newsletter that 2007 losses to major field crops including corn, wheat, soybeans, cotton, and hay totaled more than $1.3 billion. Cattle farmers, nursery and landscape businesses, and recreation and tourism also have been hard hit. Low lake levels have forced power companies such as the Tennessee Valley Authority (TVA) and Duke Energy in North Carolina to reduce electricity generation from cheap, renewable hydropower and substitute more expensive and polluting fossil fuels. By the same token, if cooling reservoir levels were to fall far enough, it could force the shutdown of nuclear power plants.
The drought is having political consequences as well, pitting downstream and upstream water users against each other. For example, Alabama and Florida successfully sued Georgia over a state plan for withdrawing water from Lake Lanier, the main source of drinking water for the Atlanta metro region. Lake Lanier feeds the Chattahoochee River, which supplies water to towns in Alabama and Florida and whose flow is key to the survival of a host of endangered species such as freshwater mussels and sturgeon. The three states have feuded since 1989 over how to divide the water, but the drought has exacerbated the problem as the various parties fight over a much-reduced volume of water.
A Dry Southeast
After an extended dry period stretching back to fall 2005, rains in the winter of 2006-2007 offered some respite to the Southeast. But the fall 2007 arrival of La Nina, a condition that recurs every few years and can persist as long as two years, diverted seasonal rains north and west. The hurricanes and tropical storms that had bailed the region out in past dry summers failed to materialize.
As the drought persisted, political leaders urged citizens to limit their water use. "I encourage all Georgians to make their dry lawns and dirty cars a badge of honor," said Georgia governor Sonny Perdue in a 25 October 2007 press release. Proactive utilities like North Carolina's Orange Water and Sewer Authority (OWASA), which enacted year-round conservation requirements after an earlier severe drought in 2002, activated additional restrictions as soon as the potential severity of the current drought became apparent. The Birmingham (Alabama) Water Works imposed a surcharge on about 25,000 of its customers for excess water usage in June.
Georgia's Environmental Protection Division (EPD) declared a level four drought response for all counties in northern Georgia (an area that includes Atlanta), prohibiting most outdoor residential water use. At the end of October, Perdue directed the Georgia EPD to modify surface water and groundwater withdrawal and drinking water permits to achieve a 10% reduction in water withdrawals in the same region. …