The renowned freshwater mussel diversity of the southeastern United States has seen significant declines over the past century due to pollution and habitat degradation. This study investigated the influences of altered river flow regime due to hydroelectric dams on food quality for freshwater mussels. Chlorophyll_a and organic content of seston was measured monthly at four sites on the Pigeon River in Tennessee and compared with four sites on the Tennessee sections of the Nolichucky River. The Pigeon River is regulated by a hydroelectric dam that causes significant daily variations in flow, while the Nolichucky River is not regulated, but features a defunct hydroelectric dam that creates an impoundment on the river. Growth and total body glycogen content of Pocketbook mussels, Lampsilis ovata, were assessed at one site downstream from the active dam on the Pigeon River and the impoundment on the Nolichucky. From July thru December 2019, chlorophyll_a concentrations in seston and growth and total body glycogen of L. ovata from the Nolichucky River were significantly greater than those on the Pigeon River, and flow rate was significantly correlated with chlorophyll_a and organic matter concentrations. While these results may suggest that frequent regulation on the Pigeon River may be reducing food availability, they warrant investigation of potentially favorable conditions for mussel populations occurring downstream from inactive dams. In July 2020, rainbow mussels, Villosa iris, were translocated to the same sites on the Pigeon and Nolichucky Rivers and to an additional site above Nolichucky Dam to investigate differences in mussel growth and condition above and below the impoundment and to verify results from the previous season with a new native mussel species.