Dam Removal

Region

Tazewell County, Southwest Virginia

Problem

A historic mill dam located in the heart of Tazewell County had long ceased to serve its original purpose of powering grain mills. However, its presence disrupted the natural flow of the Clinch River, a waterway critical to the region's biodiversity.

The dam acted as a barrier for migratory fish, such as smallmouth bass and darters, preventing them from accessing upstream habitats vital for spawning. The buildup of sediment downstream degraded water quality, affecting recreational opportunities and aquatic habitats.

Image showing a historic mill dam on the Little River in Tazewell County, with upstream impoundment disrupting stream flow and blocking fish passage.

Potential Causes

The dam, constructed during the late 19th century, was part of the industrial infrastructure that shaped the region’s economy.

Over time, sedimentation increased due to upstream agricultural runoff and urban development, compounding the ecological challenges caused by the dam.

CVI’s Solution

Canaan Valley Institute (CVI) led a comprehensive project to restore the natural flow of the Clinch River. The initiative included:

  1. Dam Deconstruction: Working with structural engineers, CVI safely dismantled the dam in phases to minimize ecological disruption.

  2. Sediment Management: A sediment excavation strategy was employed to prevent downstream accumulation during removal. This effort required collaboration with the U.S. Fish and Wildlife Service.

  3. Community Engagement: CVI partnered with local organizations to educate residents about the project’s benefits, including improved fishing and recreational opportunities.

  4. Post-Removal Habitat Assessment: Surveys of aquatic species, including smallmouth bass and freshwater mussels, were conducted to monitor recovery.

Impact

The project reconnected 14 miles of river, allowing migratory fish to access upstream habitats for the first time in over 100 years. Freshwater mussel populations, crucial for maintaining water quality, began showing signs of recovery within months of the dam’s removal.

The project also enhanced recreational fishing opportunities, boosting local tourism. During a significant flooding event caused by Hurricane Helene, the restored section demonstrated increased resilience, showcasing the effectiveness of CVI’s methods.

Image showing overflowing impoundment above a dam on the Clinch River in southwest Virginia, demonstrating the potential hazards and flood risks of dams.

What is sedimentation and why does it matter?

Sedimentation refers to the process by which particles like soil, sand, and organic matter settle at the bottom of a waterway. This can occur naturally but is often accelerated by human activities such as deforestation, agriculture, and construction.

Excess sedimentation smothers aquatic habitats, disrupts ecosystems, and degrades water quality, impacting both biodiversity and human use of water resources.