The dam was contributing to almost all of these issues, and after removal, many in-stream conditions improved quickly and dramatically.  For the first time in 40 years, the creek became obstruction-free from McCabe Golf Course to the Cumberland River.

The dam at McCabe Golf Course was approximately 4 feet tall and 50 feet wide, and it created a stagnant backwater roughly 750 feet long. It was owned by the golf course and was built in the 1970s to aid in irrigation. In the decades after the dam was installed, an estimated 300 cubic yards of mucky sediment had built up behind the dam. 

Removal of the dam enabled backwaters to flow freely again.  Improved connectivity has allowed for easier species migration and increased genetic diversity within the creek (eliminating the “aquarium” effect produced between multiple dams on a single waterway).  More than a decade later, we can observe that what was once stagnant backwater with a sediment-filled bottom is now a mix of diversified habitats including riffles (fast and turbulent shallow water), runs (fast and smooth deep water), and pools. Flowing water prevents nutrients from pooling and causing harmful algal blooms, and it prevents sediment from building up and burying bottom-dwelling microorganisms beneath muck as it accumulates behind the dam. Many aquatic species are sensitive to temperature increases, and the water that flows through Richland Creek today stays cooler than the slow-moving water that previously heated up behind the dam under the sun. Following removal, three years of subsequent monitoring showed continued stability and improved habitat. 

 This work was done in partnership with Metro Parks Nashville, The Nature Conservancy of Tennessee, and KCI Technologies.

Header Photo Credit: Photo: Samuel M. Simpkins for the Tennessean.