Hundreds of dams built on tributaries of the Hudson River estuary currently hold substantial volumes of sediment and have altered the way that sediment moves through the system. Natural resource managers are now interested in removing some of these dams to improve connectivity of aquatic habitats, restore fish spawning habitat, and reduce risks of dam failure. A high-priority management need of the Hudson River National Estuarine Research Reserve is to improve the scientific understanding of potential impacts that dam removals have on sediment transport in the estuary and deposition in downstream tidal wetlands, including how these dam-derived sediments might help offset future sea level rise impacts.
This project will address needs identified by managers and regulators to assess the immediate impacts of sediment that is released when a dam is removed, as well as the longer-term implications. The approach combines field observations with analysis of sediment transport using a proven hydrodynamic model. The project will develop watershed assessment tools for permitting dam removals and establish an improved scientific basis for considering the potential downstream benefits in regulatory decision-making.