Rash of River Impoundments Altering WNC Landscape
The U.S. Fish and Wildlife Service (Service) has observed an increase in the number of proposed river impoundments in Western North Carolina, a trend resulting largely from increased development and one that brings near-permanent alteration of natural streams and rivers.
In the first four months of 2007, the Service has reviewed or is in the process of reviewing five river impoundment projects in Western North Carolina, contrasted with seven private impoundment projects in all of 2006.
Nothing changes the nature of a stream as directly or profoundly as damming it, a tool increasingly used by developers to create artificial lakes, much to the detriment of area streams. Thus far, 2007’s projects include two impoundments for a 582-acre residential development in Rutherford County; one impoundment for a 769-acre development, also in Rutherford County; one with a 397-acre development in Buncombe County; one associated with a 1,830-acre development in McDowell County; and an impoundment for a single family residence in Catawba County. Collectively, these projects would turn more than three miles of free-flowing streams into ponds.
“These impoundments are a little-noticed facet of the region’s increasing development, but they have serious and near-permanent impacts on the streams where they’re built,” said Bryan Tompkins, a biologist with the Service.
The region’s native fish and other aquatic life are adapted to fast-moving streams with highly-oxygenated water, and stream bottoms covered in sand, gravel and rock. When an impoundment brings that section of stream to a near standstill, the water’s oxygen level drops, and the stream bottom is covered in sediment. This eliminates spawning and foraging habitat for native fish; creates a barrier dividing populations of aquatic animals into two smaller and more vulnerable populations; and alters downstream water temperature, dissolved oxygen levels, and sediment movement – all adversely affecting the health of the stream. Also, terrestrial habitat is lost as the impoundment fills.
“People are attracted to this area for its natural beauty, but lakes are not a natural feature of the Southern Appalachians – every lake in the region was created by humans and they’ve each had an adverse impact on our streams.” noted Tompkins.
Under the Clean Water Act, constructing a private dam on a stream requires permits from the U.S. Army Corps of Engineers (Corps) and the N.C. Division of Water Quality (DWQ). The Service routinely comments on these permit applications in an effort to minimize impacts to fish and wildlife. The Corps of Engineers typically makes applications for their permits available for public comment at: http://www.saw.usace.army.mil/wetlands/notices.html
“In their permitting process, the Corps of Engineers works to minimize impacts and requires mitigation for these impoundments, but once you turn a mountain stream into an impoundment, you’ve lost something that would take a lot of money and time to restore,” said Tompkins.
While many recent impoundments are simply artificial lakes associated with developments, others have more colorful proposed uses. In May of 2006, the Service reviewed a 160-acre impoundment in Caldwell County to be used as a seaplane landing area for a 3,100-acre residential development, despite the presence of an airport five miles away.
“The developer expects 10 to 12 planes to use the lake. I question whether that’s worth the resulting destruction of nearly four miles of stream,” said Tompkins.
In 2005, the Service reviewed an impoundment that would serve as a water ski lake for a 123-acre development in Catawba County.
The negative impacts of these impoundments were highlighted in a project the Service reviewed in 2006 that proposed to create a 15.67-acre impoundment as part of a subdivision abutting National Forest in Transylvania County. The impoundment would have bisected habitat for Southern Appalachian brook trout, leaving each portion of the formerly continuous population isolated and with such low numbers that the future of each portion would be in doubt. After receiving recommendations from the Service and the N.C. Wildlife Resources Commission against the project as planned, the Corps and DWQ denied the permit, a decision currently being appealed.
“The presence of our native brook trout played a large role in the denial of the permit, but there are a lot of other streams that don’t have brook trout that are being permanently altered, with each dam chipping away at the beauty and natural heritage of our free-flowing streams,” said Tompkins. “If someone is determined to have an artificial lake or pond, our recommendation is to build it outside the natural stream bed, so water is channeled from the stream to the impoundment and the overflow is channeled back to the stream. The impacts are far less.”
- Gary Peeples, U.S. Fish and Wildlife Service, firstname.lastname@example.org, (828) 258-3939, ext. 234
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