Cortlandt Lake Dam is a Class C-High Hazard concrete gravity structure approximately 225-feet long with a maximum height of about 37-feet. The dam has a mass concrete spillway with a width of 120-feet. FPA was retained by the Town of Cortlandt to perform a visual inspection, development of the Spillway Design Storm, and stability analysis. The major deficiencies of the dam included inadequate spillway capacity, deterioration of the concrete surfaces, and inoperable mid-level and low-level gates. In addition, the dam did not meet the stability requirements provided by NYS Dam Safety. Plans and specifications were prepared to raise the dam, repair the deteriorated concrete walls and spillway crest, and replace the gates. Post-tensioned anchors were designed to extend into underlying rock to stabilize the spillway for applicable loading conditions.
FPA was retained to provide construction bid review services, Resident Engineering Services, and office engineering support including construction submittals and RFI reviews during the construction and rehabilitation of the dam.