Lake Bonita Dam
Lake Bonita is located on the Mount McGregor Correctional Facility property in Wilton, New York. The 60-acre lake is retained by an earthen dam, located at its northern end. The lake serves as a water supply for the Correctional Facility and forms the headwaters of Beaver Brook, which begins at the dam and flows from south to north towards its confluence with Stony Brook. Water flows from Lake Bonita, over a concrete ogee spillway at the east end of the dam into the creek.
An evaluation of the concrete spillway indicates that it does not meet current standards for stability as required by the New York State Department of Environmental Conservation (NYSDEC). Also, the drain line through the spillway is not operational and the dam does not comply with the NYSDEC requirement that the outlet works have sufficient capacity to discharge 90 percent of the storage below the lowest spillway crest within 14 days.
MMCE retained a driller to drill borings and install piezometers through the embankment to allow an evaluation of the earthen embankment. MMCE is currently preparing plans for the Office of General Services to replace the spillway and to meet the lake drainage requirement.
