Fuss & O’Neill performed an incremental analysis to determine the spillway design flood for this high hazard dam.

We then designed and obtained permits for improvements, including protection from overtopping by armoring the dam crest and slopes with articulated concrete block. This armoring required precise calculations and careful attention to the construction specifications.

Spillway improvements included the design and incorporation of a self-supporting gravity concrete wall behind the existing spillway. The spillway improvements increased the stability of the spillway, which has a near vertical face, addressed seepage through the stone masonry, and addressed a visually apparent bulge in the spillway face.

Our design removed the former condition where hydrostatic pressure from the pond was present throughout the dam embankment, by designing a new gate structure and locating it on the upstream face of the dam. Fuss & O’Neill provided a full-time resident representative for construction phase services.