- The Nashville crayfish, Orconectes shoupi, which was federally-listed as Endangered by the U.S. Fish and Wildlife Service (USFWS) in September of 1986. The Nashville crayfish is known only from Mill Creek and its tributaries in Davidson and Williamson Counties.
- The Concord Road widening project crosses two streams that contain populations of Nashville crayfish. Those streams are Mill Creek and Owl Creek. The bridges at these two locations are to be widened. To widen the bridges, existing concrete bridge piers will be extended, causing a limited loss of crayfish habitat.
- To avoid direct effects on crayfish populations, TDOT biologists and consultants will relocate any crayfish found within the footprint of the construction area. We will also relocate crayfish from the area immediately downstream of the construction zone, as directed by representatives from the USFWS and Tennessee Wildlife Resources Agency. All crayfish collected will be transported to areas of suitable habitat in upstream sections of Mill Creek and Owl Creek, then released.
- The crayfish relocations will take place immediately prior to in-stream construction in Mill Creek and Owl Creek. To further minimize potential harm to crayfish populations, in-stream flow diversions or cofferdams will separate bridge construction activities from flowing waters in these streams.
- There are seasonal restrictions on in-stream construction. No work in flowing waters is allowed from October 1 through May 30, to ensure that reproductive activities of the crayfish are not affected by construction. This means that project construction will have to be phased in a manner that allows in-stream work at Mill Creek and Owl Creek to occur during the summer months. Work on other sections of the project can occur at any time, as long as best management practices for erosion prevention and sediment control are properly implemented.