Coordinated Reservoir Management Planning for Large-Scale Ecological Restoration

Mounting evidence from the ecological sciences suggests that the alteration of river flows downstream of reservoirs threaten native aquatic ecosystems and the services they offer. Innovative revisions to water management practices are required to improve the health of aquatic species while maintaining the benefits from current infrastructure projects. The impacts of individual reservoir operations on ecosystem vitality are often masked by the uncoordinated and compounding influences of several impoundments upstream, undermining the examination of environmental impacts from particular reservoirs in a large watershed system. This study presents a large-scale optimization model that investigates the value of coordinated reservoir management practices for ecological benefits in a large watershed with several major reservoir systems operating for a range of management objectives. The proposed model examines tradeoffs between the maintenance of natural flows at key locations throughout the watershed and traditional reservoir objectives, including flood risk reduction, municipal and riparian water supply, hydropower production, and recreation. The model is run at a daily time step to ensure that key components of flow variability are captured. An application of the model is presented for the Connecticut River Watershed, the largest river basin in New England and one of the most impounded rivers in the United States. Results suggest that coordinated changes to current reservoir operations can restore aspects of the natural hydrologic regime necessary for ecosystem persistence.