Billie Johnson Mountain Lakes Nature Preserve

Princeton, New Jersey

Billie Johnson Mountain Lakes Nature Preserve

The Billie Johnson Mountain Lakes Nature Preserve, spanning 80 acres, encompasses two historically significant dam structures—a lower earthen dam with a stone/concrete spillway constructed in 1884 and an upper stone/concrete dam built in 1902. These dams were instrumental in impounding the waters of Stony Brook, thereby creating Mountain Lakes. Functioning as vital components of the region’s history, these structures played a pivotal role in commercial ice production between 1884 and 1929, particularly within the Princeton area.

Over the years, the condition of these structures had significantly deteriorated, rendering them vulnerable to further decay and the looming threat of dam failure. To address these pressing concerns, Princeton Township engaged the services of FPA to conduct a comprehensive array of assessments, including topographic surveys, soil borings, concrete core analysis, and condition surveys of the Mountain Lakes dams. Subsequently, based on the findings derived from these field investigations, FPA developed conceptual schemes aimed at rehabilitating the dams.

Services

Water Resources Enginering

Topographic Surveys

Condition Surveys

Conceptual Schemes for Rehabilitation

Dam Rehabilitation Plans and Specifications

In 2006, FPA presented the results of the fieldwork, alongside recommended rehabilitation methods, in a detailed report submitted to the Township. This pivotal report facilitated the successful acquisition of a grant from the New Jersey Historic Trust, earmarked for the rehabilitation of these historically significant dams.

The scope of FPA’s involvement extended beyond conceptualization, as we meticulously crafted designs, plans, and specifications tailored to the rehabilitation of the Upper Dam, Lower Earthen Dam, Lower Dam Spillway, downstream channel, stone retaining walls, access bridge, culvert, and encompassed the mechanical dredging of the Upper and Lower Mountain Lakes as part of the two dams’ restoration. This multifaceted project demanded seamless coordination with key regulatory bodies, including the NJDEP Bureau of Dam Safety and Flood Control, the State Historic Preservation Office, and the Princeton Historic Preservation Commission.

Recognized for its exceptional execution and preservation of historical heritage, this project garnered a total of five prestigious awards, underscoring its excellence and commitment to upholding the highest standards in engineering and historic preservation. These accolades include the ASCE Central Jersey Branch Project of the Year award, the Professional Society of Mercer County Project of the Year award, the Dams Merit Award bestowed by the NJ Chapter of the American Concrete Institute, the NJ Alliance for Action Distinguished Engineering Award, and the 2013 Historic Preservation Award from the State Historic Preservation Office.