North Reservoir Dam

Gazing at the North Reservoir Dam, have you ever considered its vital role in Winchester’s history? This unassuming structure, stretching 780 feet long and standing 25 feet tall, is more than just a dam. It’s Winchester’s lifeline, the guardian of its water supply since 1875. North Reservoir Dam continues to serve the town to this day, a testament to its enduring design. For almost a decade, Weston & Sampson has partnered with Winchester, meticulously inspecting and rehabilitating the dam and its surrounding dikes. Their recent preliminary study and engineering evaluation revealed both the dam’s strengths and vulnerabilities. Through hydraulic and hydrologic analyses, soil borings, and dive inspections, they uncovered potential weaknesses. The embankment, made of loose sands, was found to be susceptible to liquefaction and lateral spreading in the event of an earthquake. The discovery of hazardous materials added another layer of complexity to the project. A Licensed Site Professional from Weston & Sampson collaborated with the town to assess and quantify these materials, devising a cost-effective plan for soil disposal and reuse. Currently, Weston & Sampson is leading the dam’s rehabilitation. Their multi-disciplinary team is working to reinforce the embankment, improve the low-level outlet, and replicate the surrounding wetlands. This critical project will not only bring the North Reservoir Dam up to current safety regulations, but also ensure the continued integrity of Winchester’s drinking water infrastructure.