05/10/2001

Student’s Research Finds that Upper Oconnee is Rife with Bodies of Water

By Lee Shearer; Morris News Service - The Augusta Chronicle

Minnesota proudly proclaims itself the "Land of 10,000 Lakes," but that's minor league compared to Georgia, a University of Georgia graduate student has discovered. As part of his research for a master's degree in conservation ecology and sustainable development, Michael Merrill decided to see if he could determine just how many "impoundments" there are in the upper Oconee River basin - a 2,900-square-mile drainage area stretching up from Milledgeville through 18 Georgia counties, including Clarke. An impoundment is an area in which water is penned up. The number was a lot bigger than he'd imagined, Mr. Merrill found after analyzing records maintained by the U.S. Geological Survey and other agencies: 5,467 impoundments in the upper Oconee basin. About 3,500 were created by building a dam in a stream or river, but many were created simply by digging a big hole off to the side or at the headwaters of a small stream. "I was stunned," Mr. Merrill said. In the upper Oconee basin, they range in size from massive Lake Oconee (19,000 acres) and Lake Sinclair (15,300 acres) to tiny farm ponds stocked with hatchery-bred catfish. Intrigued, Mr. Merrill went beyond that to look at all of north Georgia, roughly the top half of the state above the fall line, where Georgia's Piedmont gives way to the Coastal Plain, and got even bigger numbers. In his first rough analysis, Mr. Merrill found 10 times as many water bodies - about 46,000. "And I think that's an underestimate," he said. "Once you start thinking about how much energy and money we've poured into putting these here, it's astounding." It makes it tempting to call Georgia "The Land of 10,000 Impoundments," Mr. Merrill joked. The difference is that all those lakes in Minnesota are natural while Georgia's are man-made. Most of the upper Oconee impoundments are small, he said: "amenity" ponds in subdivisions or little farm ponds designed for fishing, erosion control or cattle watering comprise the vast majority. But all those little ones account for about as much flooded land as the two giant impoundments, Oconee and Sinclair, Mr. Merrill said. About 2.3 percent of the land surface of the entire upper Oconee basin is covered in water as a result - an area of about 232 square miles, nearly twice the size of Clarke County. About 519 miles of flowing river and stream have been converted into still lakes and ponds, comprising about 8 percent of all the river and stream miles in the watershed. What was once a vast, free-flowing network of streams and rivers has now been chopped into hundreds of disconnected little stretches, hardly any of it truly free-flowing, Mr. Merrill said. That's what ecologists call "stream fragmentation," and it has far-reaching effects on the plants and animals that live in and near rivers. Fish that migrate upstream to spawn can no longer do so, for example, which means not only that those species might die out, but also that the bird species that depend on them for food could be affected. When a native fish dies out in one part of a stream - the kind of thing that happens in drought - fish from another stretch of stream are no longer able to repopulate the area when conditions get better. Mr. Merrill wasn't the only one taken aback by the numbers. "It really opened my eyes in terms of the amount of land under water and how we've really changed the plumbing of the whole upper Oconee watershed," said Judy Meyer, a University of Georgia stream ecology researcher and former president of the Ecological Society of America. The graduate student's research has meant a slight shift in research for his adviser on the university faculty, Liz Kramer. "It certainly raised a lot of questions in my mind about how we manage water in this state. There's a lot of water we don't have access to," said Ms. Kramer, who had high praise for Mr. Merrill, 27. "He's definitely one of our top students, a real creative thinker, plus a real pleasant guy to work with," she said. Ms. Kramer and fellow faculty member Jim Kundell are in the middle of a multiyear study that looks at how Georgia's land-use patterns have changed in the past 25 years, a $1 million project funded by the Turner Foundation. After Mr. Merrill's paper, Ms. Kramer and Mr. Kundell decided they needed to take a statewide look at such questions as the extent of stream fragmentation, the number of impoundments, how many have silted and become swamps, and how much water they lose to evaporation.

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