Stillwater Dam Rehabilitation Project

The Stillwater Dam is an existing structure located on the Beaver River in the Town of Webb, Herkimer County, New York. The dam regulates the outflow of the Stillwater Reservoir and is owned and operated by the Hudson River-Black River Regulating District, a public benefit corporation. Current downstream benefits include flood control, pollution abatement, downstream power production and recreation.

After 60 to 70 years of weathering in a harsh, mountain environment, the concrete structure showed surfacial deterioration and exposed aggregate. Leakage paths had become established through the construction cold joints. Several of the gates were leaking and appeared to be very worn. The concrete and the cast iron thimbles in the discharge chutes showed evidence of cavitation and erosion. Visually, the concrete and leakage created a concern. In addition, the old concrete, when exposed to weathering, broke down very quickly. 7 pp.