The 80 acre Mountain Lakes Preserve contains a lower earthen dam with a stone/concrete spillway built in 1884 and an upper stone/concrete dam built in 1902. The dams were used to impound the waters of the Stony Brook and create Mountain Lakes. These structures and associated facilities used for commercial ice production from 1884 to 1929 are of historical significance to the Princeton area. These structures had deteriorated over time and fallen into serious disrepair requiring remedial measures to avoid further deterioration and the possibility of a dam failure. FPA was retained by Princeton Township to perform topographic surveys, soils borings, concrete cores and condition surveys of the dams at Mountain Lakes. Based on these field investigations, FPA developed conceptual schemes for the rehabilitation of the dams, and the findings of the field work together with recommended methods of rehabilitation were presented in a 2006 Report to the Township. The report aided in obtaining a grant from the New Jersey Historic Trust to rehabilitate the Historic Dams.
FPA prepared designs, plans and specifications to rehabilitate the Upper Dam, Lower earthen Dam, Lower Dam Spillway, downstream channel, stone retaining walls, access bridge, culvert and also includes the mechanical dredging of the Upper and Lower Mountain Lakes during the rehabilitation of the two dams. The project was coordinated with the NJDEP Bureau of Dam Safety and Flood Control, the State Historic Preservation Office and the Princeton Historic Preservation Commission. This project was awarded the Dams Merit Award by the NJ Chapter of American Concrete Institute, as well as the ASCE Central Jersey Branch Project of the Year award.