Although not problematic within this reservoir, unacceptably low dissolved oxygen concentrations farther downstream in the system of reservoirs in the Cumberland River Basin have caused concern. This model study was undertaken to evaluate the water quality (specifically temperature and dissolved oxygen) impacts of operational changes at individual reservoir outlet structures. The study was also designed to reveal the interactions between hydrodynamics and stratification within the reservoir. Unstable stratification is thought to be responsible for additional problems in the reservoir: absence of an anticipated substantial fishery and a less than desirable amount of contact recreation. The concept of installing submerged weirs at the mouths of two of the reservoir's embayments within an established recreational site was proposed to help alleviate these 2 problems. As Cordell Hull Lock and Dam operates as a run-of-the-river navigation project on the main-stem Cumberland River, no significant operational changes at this site are possible. The reservoir is characterized by high flows, intermittent moderate to weak thermal stratification, and a relatively shallow pool. These factors combine, as was demonstrated by the model testing results, to preclude significant control over the release quality characteristics. However, the advective nature of the reservoir presents an advantage. Any changes to the quality of incoming water of Cordell Hull Reservoir will be propagated downstream, largely intact. (EDC).