Dam removal projects restore WNC waterways

Nonprofits, community groups and government agencies throughout Western North Carolina are now working to remove a legacy of outdated dams. Although challenging, the process offers benefits for the wildlife, safety and recreation potential of the area’s waterways.

Ecology provides the primary impetus for most dam removal projects. At the most basic level, eliminating these barriers allows native species to reach previously inaccessible habitats. “We have the highest freshwater species diversity in the country right here in the southeastern U.S.,” says Jason Farmer, fisheries biologist for the Cheoah Ranger District of Nantahala National Forest. “We now manage our streams to give those species the greatest opportunity to persist and expand into other areas.”

Even when a species is already present both above and below a dam, removal can strengthen the health of the population through recombining genetically separate groups. Farmer says that this was the case for the hellbender salamander in Santeetlah Creek. When the Forest Service removed the dam, the two once-fragmented populations began mixing to mate. The additional diversity reduces inbreeding and improves the hellbender’s prospects in the area.

A small dam removal project can run anywhere from $15,000 to $150,000. About 75 percent of that total accounts for the actual dam demolition and stream restoration, while the remaining 25 percent covers the necessary design, engineering and permitting.

One of the largest expenses is the removal of the sediment that accumulates behind the dam over the course of its lifespan. Heavy equipment is usually necessary to dredge loads of muck from the streambed, and toxic waste disposal may be required for sediment associated with industrial dams. In especially vulnerable environments, endangered species surveys and relocation tack on further costs.

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