Below Shelbyville to the Southeast, the Duck is impounded by Normandy Dam, a Tennessee Valley Authority project of the early 1970s which was built for flood control and recreation.

Downstream in Maury County is the Yanahli Wildlife Preserve, occupying land which was meant to be another TVA reservoir.

The Columbia Dam was never completed, however, when an endangered species of mussel was found in this section of the Duck and studies showed the project costs would far exceed benefits.

Private funds have been spent on this dam to rehabilitate it to resume electrical power production; however, this has not proven to be successful.

Between Columbia and Centerville, the Duck cuts through the Western Highland Rim and is joined by several major tributaries, notably the Piney River.