The Drought of 2007: A Foreshadowing of Things to Come?

By Lori Keesey, posted on July 2nd, 2008 in Articles, Disasters, Earth Observation, Water

The epic drought that stretched across the southeastern U.S. in 2007 won’t be forgotten soon. Water supplies plunged to perilously low levels and public officials imposed draconian conservation measures to protect a resource that had become more valuable than gold. By late fall – after weeks of negligible rainfall and no end in sight – Georgia Governor Sonny Perdue did what came natural to him.

He stood on the steps of the Capitol and prayed for rain.

It remains to been seen whether Dixie can expect more of the same this year. Although the National Weather Service reported that the region had enjoyed near-average rainfall during the winter months —-precipitation needed to recharge aquifers and raise reservoir levels – no one is ready to say that the South is out of the woods quite yet. “If we have a dry summer or fall, we’ll be back with the same problems again,” said Todd Rasmussen, a hydrology and water resources professor at the University of Georgia.

The Georgia state climatologist isn’t taking any chances, either. Using predictions generated by the federal government, David Stooksbury warned his state to expect extreme-to-moderate drought conditions through at least the summer of 2008.

The U.S. Drought Monitor, a weekly monitoring tool produced by several federal agencies and the University of Nebraska-Lincoln, also hasn’t sounded the “all clear.” In late April, it reported that enough precipitation had fallen in southeastern Tennessee and northern Alabama to downgrade their drought designations. Though no longer suffering from an exceptional drought, they are, nevertheless, experiencing a severe one.

Equally worrisome is Lake Lanier, one of several major reservoirs serving Georgia, Alabama, and Florida. It still remains 14 feet below normal levels.

“Drought is something we expect in Georgia. It’s not unusual,” said Assistant State Climatologist Pam Knox, who traces the drought to 2006 when the state began experiencing lower-than-normal rainfall levels. “The severity of last year’s drought was what was so unusual. It was a 100-year event.”

A much larger issue, she and other experts believe, is whether the water woes of 2007 are simply a foreshadowing of things to come. Without a change in attitude about water use – particularly given the region’s explosive population growth and climatic conditions that only Mother Nature can control – the issue of water shortages won’t go away anytime soon.

Flashback to 2007

Citing the events of 2007, the specter of dwindling water supplies should give most people pause. It certainly painted some indelible images.

Perhaps the most dramatic occurred at Lake Lanier in northern Georgia. The 38,000-acre reservoir, which the U.S. Army Corps of Engineers built by damming the Chattahoochee River in the 1950s, had dropped so low that parts of the lake bottom had become visible, revealing an abandoned stretch of Georgia Highway 53, home foundations, and a part of Gainesville’s Looper Speedway – all not seen for more than 50 years.

Although the Corps has originally built this expansive stretch of water to provide hydroelectricity and flood control, it has become an important drinking water source for 75 percent of Atlanta’s burgeoning population. It also serves power plants and endangered species farther downstream in Alabama and Florida.

“Things were looking pretty dire,” Knox recalled. The other reservoir serving Atlanta, Lake Allatoona, also fell below average and across the state rivers flowed at less than half of their normal rates.

By then, life in one of the fastest-growing regions of the country had gotten ugly. Despite months of water conservation that banned or severely restricted outdoor watering, it was widely reported in November that the denizens of Atlanta – the most populous city in the South – only had 79 days of water left. A small town in Tennessee had already shut down water except for about three hours a day. Crops failed. Nurseries and foresters lost millions. And politicians and policymakers in three states launched salvos in their long-running war over the distribution of water from the reservoirs, all arguing for greater amounts to satisfy demand.

And still it did not rain.

2007 is now on record as the driest or second driest year in the Southeast. A mere 31.85 inches fell in Atlanta, well below the average of 48 inches. Alabama faired worse. Birmingham had just 28.86 inches, a full 25 inches below average, and Huntsville received a paltry 28.65 inches, 29 inches below average. The rest of the southern states also experienced an extraordinarily dry year.

The Cause

Some might want to link these declining rainfall levels to global climate change, particularly in light of the Intergovernmental Panel on Climate Change (IPCC) report released last year that predicted intensified droughts over wider geographical areas and increased temperatures because of the emission of greenhouse gases and other human activities.

Andy Grundstein, an associate professor in the University of Georgia’s Department of Geography, isn’t ready to blame the emission of greenhouse gases on the region’s continuing drought, however. He recently compared 100-year soil and rainfall data and found that the periods of drought – even the exceptional ones – are part and parcel for the Southeast. “I didn’t see an increase in the number or intensity of droughts,” he said. “Yes, we’re in the midst of drought, but in the South, it’s been a cyclical thing. However, future patterns may change as the Earth continues to warm.”

Consistent with other studies, Grundstein’s research also revealed that, in fact, the South is getting slightly wetter and the temperatures have actually gotten a little cooler. Knox agreed. “You need to look at the end points,” she said. “There is no doubt that warming is occurring in the world, particularly in the Arctic and Greenland. There’s no question.” But in Georgia, historic data do not bear out those trends, she said.

The more immediate concern is whether another weather pattern that formed thousands of miles away from the American Southeast will soon ease its grip on the planet, she said. In 2007, a strong-to-moderate La Niña weather pattern took hold in the Pacific Ocean. Such a pattern usually means that the Southeast experiences higher-than-normal temperatures and less-than-normal rainfall in the winter months, precipitation that restores water reserves used during the spring and summer growing season. That certainly happened over most of the Southeast in 2007.

La Niña also usually results in a more active tropical storm season. However, much of the South did not benefit from that particular feature last year. Exacerbating the situation was a high-pressure system that had developed over the Atlantic Ocean. Reinforced by the dry conditions on land, it persisted, effectively forming a large protective bubble over the region that blocked moisture-bearing tropical storms from moving into the area.

The double whammy resulted in record-breaking or near record-breaking drought conditions, particularly in Georgia and Alabama.

A Glimmer of Hope

However, Knox said there is a glimmer of hope. Evidence shows that La Niña is continuing, which may allow a more active storm season.

“It’s a potential way to help break this drought,” said Marshall Shepherd, a current member of NASA’s Precipitation Measurement Mission Science team and associate professor for the University of Georgia’s Department of Geography. However, Shepherd is particular about the types of storms that could deliver the South from its current peril. Weak tropical storms, particularly ones that park themselves over the region for a few days, would provide the fix, he said.

He bases his beliefs on a study he did using a decade’s worth of data from NASA’s Tropical Rainfall Measuring Mission (TRMM). He and his colleagues examined the amount of precipitation different types of storms produce, including tropical depressions and category-five hurricanes. Hands-down, the weakened tropical storms emerged as the big contributors to hurricane-season rainfall, not the “monster” category three-to-five storms.

Larger Concern

As the region awaits the start of the 2008 hurricane season in a few weeks, Rasmussen and Grundstein – both born and bred Westerners well accustomed to perpetual water shortages – believe Southerners need to direct their attention instead to broader questions and allow the events of 2007 to serve as a catalyst for change.

Perhaps understandably so, “people here are profligate with water,” Grundstein said. With average rainfall of at least 50 inches a year, the region isn’t practiced at the art of conservation. When residents turned on the faucet in the past, they got water. A plentiful supply was always available, particularly in the good years.

According to the U.S. Census Bureau, however, three of Atlanta’s suburban counties rank on the nation’s top 10 list for fastest population growth. “When I was a kid growing up in California, my family and I literally watched the city of L.A. grow,” Rasmussen said. “Atlanta will continue to grow, too.” But with population growth comes increased demand for water, a commodity dictated by the whims of Mother Nature, as the 2007 drought so vividly demonstrated.

With demand on the upswing, the only long-term solution lies with conservation – even under normal rainfall conditions, Rasmussen said. Luckily, technology is available to curtail use in homes and businesses. Low-flow and waterless toilets, frontload washers, landscaping techniques that feature fountains and hydroponic plants, and the treatment of wastewater all could contribute to reducing consumption.

Whether these and other measures become commonplace depend on how quickly people’s attitudes change – not just in the Southeast but also across the U.S., he said.

At this point, America hasn’t set a very good example, he said, recalling his trips to China, Honduras, and the Middle East. When he visited these places, the local people repeatedly spoke of the “American way of life.” When he asked them precisely what they meant, all cited big lawns, washing machines, dishwashers, swimming pools, golf courses, “everything involving water. We have set an example of profligate water use and they want that, too,” Rasmussen said.

Learning how to become better stewards of the only resource that sustains life is not just a lesson Americans must learn, he added. “What example do we set for the rest of the world?”