Dam Removal at Mill Creek Park and Greenway

Project Date: June 2018

Location: Nashville, TN

Waterway improved: Mill Creek

Restoration methods: Dam removal

Dam removal at Mill Creek Park

In June of 2018, the Cumberland River Compact removed a dam on Mill Creek at Mill Creek Park. Because of the presence of the dam, Mill Creek’s water quality was negatively impacted by excess sediment, nutrients, and pathogens, and also by low dissolved oxygen.

The Mill Creek Park Dam removal was one of three dam removals on Mill Creek that the Cumberland River Compact and its partners completed in 2018. Together, these projects won a Governor’s Environmental Stewardship Award in 2019. Thanks to the removals, all Davidson County sections of Mill Creek’s mainstem – about 21 miles – are now free-flowing to the Cumberland River for the first time in 50 years.

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.

Prior to the dam removal work, 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 to avoid the reproductive season for this at-risk species.

A Nashville Crayfish in the sand. — Nashville Crayfish. Photo by Dominic.

The dam at Mill Creek Park and Greenway was on Mill Creek near Culbertson Road. At one time, it provided landowners with a low water crossing. The dam was roughly 50’ across and made of solid concrete. Though the dam created an easier passage for creek crossing, it also had many detrimental effects on the native aquatic habitats and the healthy flow of the creek. Blocked water created a backlog of stagnant backwater with a mucky, sediment-filled bottom.

This project required the removal of nearly 40,000 lbs of concrete.

Removal of the dam enabled stagnant backwaters in Mill Creek 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). Flowing water prevents nutrients from pooling and causing harmful algal blooms, and it prevents sediment from building up and burying bottom-dwelling microorganisms 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.

An excavator removing concrete from a dam. — The project required the removal of nearly 40,000 lbs of concrete.

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.

A healthy stream surrounded by vibrant grass and trees. — Mill Creek after the dam’s removal.

This work was done in partnership with Metro Parks Nashville, the US Fish and Wildlife Service’s Aquatic Restoration Crew, Collier Engineering, Metro Water Services Nashville, the Nashville Zoo, Merryman-Farr, TN Department of Environment and Conservation (TDEC), The US Army Corps of Engineers, Jen-Hill, TN Wildlife Resources Agency (TWRA), BDY Environmental, Mill Creek Watershed Association, Friends of Mill Creek Park, and individual volunteers.