There Are Bugs In Your Chattahoochee River Drinking Water…. And That’s a Good Thing!

The study of the bug life in the Chattahoochee River and protecting this unique trout water is the work of a non-profit group made up mostly of fly fishermen.

Daryl Kirby | April 6, 2005

The Chattahoochee River is crawling with bugs. For the millions of Georgians in the Atlanta area who depend on the river for drinking water, that might be a cause for concern.

Worry not. You’re not going to find a creepy-crawly surprise in the bathtub, no stonefly or caddis hatches in the toilet.

Few of the folks whose water comes from the Chattahoochee even know the origin of their water. Without it, they wouldn’t live in those fancy neighborhoods and wouldn’t have the “convenience” of a big-box shopping plaza at every intersection. Fewer still lift a finger to protect this precious resource.

Despite the indifference of many, the bug life in the river from Buford Dam down to the Paces Mill/Hwy 41 bridge area shows that the Chattahoochee River is in pretty good health.

Many of the folks who recognize the value of the Chattahoochee — and the ones who are fighting to protect the river — are trout fishermen. They know that a river full of bugs is a healthy river and one that will be home to healthy trout. And thanks to the work of a non-profit group started several years ago made up mostly of trout fishermen, we all can find out just which bugs are found in the river at certain times of the year. That information is invaluable when deciding which fly to tie on to match-the-hatch and fool a trout.

The Chattahoochee River tailrace below Buford Dam is a large fishery where many stocked fish carry-over, and it’s home to some trophy trout.

The Chattahoochee Coldwater Fishery Foundation was the idea of Chris Scalley, who grew up within walking distance of the river in Roswell. Chris fell in love with the river and fly fishing, and he made those things his life’s work. Chris owns River Through Atlanta Guide Service and averages more than 200 days a year on the river.

In an effort to become a better Chattahoochee fisherman and guide, Chris began setting bug traps in the river to learn what food was available for the trout.

“I originally sampled insects for bait,” he said. “I had bug catchers out there, I used what I found for bait. Then I started fly fishing. I learned some hatches were disappearing, some were appearing. The bugs in the river are like canaries in the coal mine. They tell you so much about the health of the river.”

He started noticing changes in the bug populations and varieties, something he suspected was due to changes along the river.

“I started the Foundation in ’98,” Chris said. “It was my idea, but Lisa Klein and Don Pfitzer were part of the influence for getting it started.”

Don Pfitzer is retired from the U.S. Fish and Wildlife Service, where he spent 33 years as a biologist and eventually served as the Assistant Regional Director of the Southeast. He is an author of many trout-fishing articles and “The Hiking Guide to Georgia.” Don also has a Masters in entomology, and his knowledge of bug life has been instrumental in helping Chris and the Foundation catalog what they were finding in the Chattahoochee.

Lisa Klein spent several years as the WRD Fisheries biologist on the trout waters of the Chattahoochee River from Buford Dam to Atlanta before back problems forced her off the river. Lisa’s work included documenting natural trout reproduction in the river, something very rare for a tailrace fishery, especially in such a southern climate.

Both Dona and Lisa are still members of the Board of Directors of the Foundation, which is a non-profit organization that can accept tax-deductible contributions. Also a Board member is Bill Couch, who runs the Buford Trout Hatchery.

Specifically, the Foundation does the following:
• Conducts studies of macro-invertebrate life in the river, including documentation of food sources for wildlife in the river.
• Assists in the control of bank erosion by planting vegetation and building structures.
• Locates sources of non-point source pollution (i.e., runoff) and constructs catch basins with filters or limestone treatments.
• Constructs structures to provide cover for wildlife.
• Documents natural reproduction of trout.
• Makes the results of all studies available to the public, other conservation organizations, and governments.

As a relatively new organization, funds are limited, and the group relies heavily on the work of folks interested in learning about and protecting the river.

“Most of the volunteers are fishermen,” Chris said. “We take the bug samples every three months. They are quarterly, and we have people who volunteer to pick and sort the bugs. We require that they take an Adopt-A-Stream entomology course put on by the counties. That’s part of the Adopt-A-Stream concept, to count invertebrate life in these creeks to tell us how healthy the watershed is.

“We get an overwhelming number of fly fishermen because they want to learn about the river, they want to learn about the food sources for the fish. We also get children who just love to play in creeks, and they have a ball at these things. We’ll get 30 or 40 people at a time.

“Our success as guides and fishermen… getting out there and volunteering for the bug sampling helps our success. The more you learn the better. It’s been a huge success to generate interest on that level, where people are looking beyond the surface of the river. It gets people hands-on, in the river, and they are becoming aware of its quality.”

Samples are taken at six stations along the river at established stations — Bowmen’s Island, Settles Bridge, Jones Bridge, Island Ford, Morgan Falls, and Cochran Shoals.

“We determined those sites with Lisa and Don’s help. We want to get a snapshot of the river quarterly,” Chris said.

One of the tools used to measure the biomass is a Hester Dendy.

“We call them HDs. It’s basically just square pieces of hard-board that are about four inches by four inches. They look like a sandwich. They are secured with a bolt with spacers in between. The creatures will get in this little bug sandwich, and they’ll inhabit it. We get colonizing insects that way. We secure them on a permanent structure in the river, typically a logjam. The colonizing insects and other invertebrates… crustaceans, you name it… we’ve even found salamanders in the HDs.

“And then we have another sample method called a surber, and this is a d-frame, heavy-duty net. Surber catches any bottom-dwelling insects we stir up. The current washes anything down into the net. We have a bracket, a square foot that we’ll set down, and we reach down and turn over each piece of gravel and cobblestone — but it’s in that one set area, so these samples are quantitative. We collect them from the same place every quarter. We put what we find in zip-locks, put them on ice, and Don is our entomologist, so he identifies everything.”

What they have found provides a wealth of information for fly fisherman, and it’s all available on a hatch chart at their website at Their, anglers can see that in addition to a year-round BWO Mayfly hatch on the river, there is a Sulphur Mayfly hatch that peaks in May and June, a Caddis hatch from March through June, and Stoneflies are available from January through the first of June.

In addition to showing what food is available to trout during each month, the Hatch Chart includes recommendations for dry-fly and subsurface fly patterns. While the samplings efforts are invaluable to fly fishermen, the importance of the Foundation’s work is in monitoring the health of the river.

“Trendwise, we’re starting to learn what is going on in the river. The droughts before last year had a big impact on what we found. We were finding more crustaceans in the river, like scuds, which is like a freshwater shrimp. Fish love them. A lot of people think of them as an indicator of a really productive stream. If they have scuds, it’s a very productive stream. We think a reason for this is that in the Chattahoochee there is a minimum flow from the discharges at Buford Dam. We’re blessed, we have this huge reservoir, and you’ve got this constant, uniform flow of water that is a uniform temperature. It’s cool, and it’s high in oxygen.

“I think we’re at the bottom end of a cycle here. We had such a wet year last year, and they just kept releasing water. We’ve had a perpetual flood all year. That’s helped to blast out a lot of the sediment that had built up. Before last year we had about five years of drought, and what we saw during the drought years was that the Caddis Fly population declined, which we all love and know about the Hooch, it’s got this awesome Caddis hatch. But we were seeing more crustaceans. The river is more silty during the droughts. During drought we have weedbeds grow up in the sediment deposits. Weeds produce everything from Mayfly to Scuds. The other irony is that the trout were reproducing a heck of a lot better in drought condition because the eggs weren’t scoured. So we had a lot more natural reproduction in the river because those eggs are able to incubate without being washed away.

“With the high flows last year, now there’s more exposed substrate, and that’s more favorable habitat for the Caddis, and I expect the trend will go back to more Caddis. Right now we have an excellent mix of everything.”
So what do the bug counts say about the health of the river? Chris said that an index they use shows that the river is holding steady. Some bugs show trends of slight declines, but others are coming on. Anecdotally, Chris thinks the news is even more encouraging.

“I think that we’re getting better. It’s hard to believe isn’t it? We’re seeing more diversity. With the Chattahoochee, the difference with us and say a freestone mountain stream in north Georgia — we have the same geology — but the temperature is constant. You get a mountain stream, you get warm temperatures in the summer, cold, cold temps in the winter. We don’t get that fluctuation. So we get basically the same kind of food webs, or variety of insects that you find in north Georgia, but multiply that by five.

“I’m looking for a super season,” Chris said. “It’s going to be awesome.”

Meanwhile, in addition to counting bugs, Chris and the other volunteers keep an eye out for things like illegal clearing along the riverbanks, discharges into the river that can harm water quality, and silt flows that could indicate construction sites that aren’t following silt-fence regulations. All of these are things that could put an end to the unique trout fishery that is the Chattahoochee River tailrace.

For information on the work being done by the Chattahoochee Coldwater Fishery Foundation, contact Chris Scalley at (770) 650-8630, or you can email [email protected]

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