Our team of professionals was contracted to conduct a comprehensive engineering assessment and recommend remedial actions in accordance with NYSDEC regulations for a large Class C Dam. Constructed in 1898, the dam is located at the northern end of Indian Lake, which is a reservoir in New York State. It consists of a mass concrete core, a stone masonry exterior surface, and stone masonry piers that support a walkway for access above.

To conduct a comprehensive analysis, we first located the original drawings of the structure in the state archives. These drawings significantly supplemented the limited records previously available. We then cross-verified these drawings with a comprehensive field survey and a rigorous boring program to form the basis of our structural stability analysis.

Since the reservoir holds a large volume of water and there is a potential for cascading failure downstream, we conducted a dam breach analysis and created breach mapping to reach the Indian River below the dam, along with a portion of the Hudson River. We analyzed potential improvements to enhance safety and hydraulic capacity at the site. Our recommendations included adding a vertical lift gate in an existing log flume and treating the non-overflow masonry section like an auxiliary spillway for high flows.