Removal of Northborough Reservoir Dam

The Town of Northborough hired Weston & Sampson to assist in breaching the Northborough Reservoir Dam to reduce hazard potential associated with the dam and provide ecological restoration of the impoundment and stream.

Design for the dam breach entails removal of the existing spillway and a newly created channel designed to simulate a natural stream channel reach. Our team developed a hydrologic and hydraulic (H&H) model calibrated using data from river gauges within the drainage basin to better reflect the fluvial geomorphology of the proposed conditions to ensure a stable post-construction site. The model output demonstrated that breaching the dam at the existing spillway would meet hydraulic requirements and result in a structure that the DCR ODS would consider non-jurisdictional. It also showed that the discharge stream could be conveyed through an existing culvert, which resulted in a significant reduction in the anticipated construction cost.