Waterbury Dam is a high hazard potential dam located on the Little River, about 2.5 miles above its confluence with the Winooski River in the Town of Waterbury, Vermont (Figure 1).

Figure 1

The construction of the Waterbury Dam and Reservoir was authorized by the Director of Emergency Conservation Work in June 1933 for purpose of flood risk management. The dam was designed and constructed by the USACE between 1935 and 1937 using contract services and Civilian Conservation Corps (CCC) labor. The dam was placed into operation in 1938. The dam is owned and operated by Vermont Agency of Natural Resources, Department of Environmental Conservation (VT DEC).

The main components of the project include a rolled earth fill embankment dam, outlet control house and gated outlet works, a downstream foundation well control house, and an unlined rock channel spillway with an uncontrolled ogee weir and three Tainter gates (Figure 2).

Figure 2

The Waterbury Dam reservoir provides for water storage during storms to reduce downstream flooding. In addition, outlet flows provide water for power generation and the reservoir is used for recreation. The hydropower generation facility was constructed at the base of the dam in 1953 and is owned and operated by Green Mountain Power. The State of Vermont owns and operates recreation facilities on the reservoir.

Study Authority and Study Non-Federal Cost Share Partner: The Dam Safety Modification Study is being conducted in accordance with authority provided in Section 1177 of the Water Resources Development Act (WRDA) of 2016, Title I of Public Law 114-322, as amended. The non-federal cost share partner for the study is VT DEC.

Study Purpose: The Dam Safety Modification Study will identify the proposed scope for a project for the rehabilitation of Waterbury Dam. Structural deficiencies were identified in the spillway Tainter gates during studies on the spillway in 2005. An operational risk reduction measure put in place until the gates are rehabilitated. The project also has a history of alkali-silica reaction (ASR) which has caused deterioration of the concrete structures.

Study/Project Schedule:

• Release of Draft Environmental Assessment for Public Review in January 2025
• Dam Safety Modification Study Completion in Spring 2025
• Preconstruction engineering and design in 2025-2027
• Construction in 2027-2030 (depending on availably of funding)