Mill Creek’s water quality was negatively impacted by the presence of the dam which caused excess sediment, nutrients, and pathogens, and low dissolved oxygen. After removal, many in-stream conditions improved quickly and dramatically. 

Prior to removal work, Compact staff and volunteers walked or paddled 37 miles of streams in the Mill Creek Watershed, inventorying the 3 dams we removed on Mill Creek, plus 16 more dams on tributaries to Mill Creek. Most of the dams were small, no longer functioning as intended, and all but forgotten. Of the 19 we inventoried, only one was on the National Inventory of Dams, the most comprehensive database of dams at that time. 

The Compact and its partners also conducted crayfish sweeps, as Mill Creek is home to the endangered Nashville Crayfish. The team found and relocated 400+ crayfish and scheduled deconstruction work for June and August in order to avoid the reproductive season for this at-risk species. 

The dam at McRedmond Farm was originally built to create a swimming area, but over time the dam failed. At the time of removal, a gap had opened up through its middle. Exposed and submerged “I-beams” (steel structures used for various purposes in construction) remained in that gap and had become a hazard for paddlers, while remains of the dam elsewhere were negatively impacting water quality and wildlife habitat. Three large steel girders, their concrete bases, and the I-beams were all removed as part of the project. This work opened up a 25-foot channel for water to flow through. Two small sections of the original structure were left in place at the request of the dam’s owners. Low-impact equipment was utilized for deconstruction, which minimally impacted streamside areas and did not require the removal of any trees. All areas disturbed by construction machinery were stabilized with native seed, straw, and other plantings.

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).  What was once a stagnant backwater with a sediment-filled bottom is now a mix of diversified habitat 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 behind the dam. Many aquatic species are sensitive to temperature increases, and the water that flows through MIll Creek today stays cooler than the slow-moving water that previously heated up behind the dam under the sun. 

This work improved paddling conditions on Mill Creek and dovetailed nicely with the Tennessee Scenic River Association’s canoe access builds on Mill Creek’s mainstem. We’re proud to have lent a hand or two at several of these builds. In total, there are now six public access points in Davidson County on Mill Creek where paddlers can “put in” or “take out” their boats.

This work was done in partnership with the dam’s owners, KCI Technologies, Metro Water Services Nashville, the Nashville Zoo, the TN Department of Environment and Conservation, and the TN Wildlife Resources Agency and with help from numerous volunteers.