Development of multiple hydroelectric projects at navigation dams on large river systems can result in a number of environmental impacts, including potential reductions in dissolved oxygen (DO) concentrations. This study presents a method for generating hydropower development alternatives for evaluation by planners by quantifying the trade‐offs between water quality and power generation. This method employs a Streeter‐Phelps model to simulate DO and the bounded implicit enumeration algorithm to solve an optimization model formulated to maximize hydroelectric energy production. A portion of the upper Ohio River basin was selected to illustrate the methodology. The results indicate that various alternatives that meet the specified DO constraints can be generated efficiently. These alternatives are nearly optimal solutions with respect to the modeled objectives but are different with respect to decision variables.