The ACB Auxiliary Spillway and Gate Replacement Project served to make improvements to an existing dam that impounds a crucial water storage facility that supports consistent and reliable water supply in Southern New Hampshire.

The scope of the project included several critical components aimed at improving the dam’s redundancy, operational efficiency, and safety. Hydraulic modeling was conducted to assess current and future water flow conditions, ensuring that the new infrastructure could handle the inflow design floods effectively.

Key improvements included the installation of two new stainless steel, double-leaf weir and slide gates, which provide precise flow control and improved redundancy during storm events. The project also required the removal of an outdated concrete intake structure that was no longer necessary. A new articulated concrete block auxiliary spillway was installed to enhance the dam’s flood management capacity, ensuring that excess water can be safely discharged during high-flow events. To further reinforce the structure, a concrete cutoff wall was constructed, providing additional stability and preventing seepage through the dam embankment.

Throughout the project, extensive permitting processes were undertaken to comply with environmental regulations and ensure minimal ecological impact. Construction oversight was a key component to guarantee that all improvements met engineering standards. These enhancements collectively strengthen the Dam’s role in water resource management, ensuring a stable and sustainable water supply for the surrounding communities.