Restoring Ballinger Lake Dam in Medford Lakes

Medford Lakes is a borough in Burlington County, New Jersey that consists of 22 lakes, and more than 10% of the homes there are log cabins. Located just 25 miles east of Philadelphia, within the New Jersey Pinelands Commission Management Area, the Borough is overseen by the Medford Lakes Colony (MLC), a homeowners association that manages social events and recreation activities for the community. Medford Lakes and its surrounding neighborhoods contain approximately 60 dams. The MLC retained Princeton Hydro to provide various engineering services for multiple dam structures throughout the Borough, including periodic visual inspections, dam breach and inundation analysis, and maintenance and repair work.

Ballinger Lake, located at the intersection of Lenape Trail and Stokes Road, contains a dam that is registered as a Class I – High Hazard Dam with NJDEP Division of Dam Safety. Immediately downstream from the dam is Main Street Medford Lakes, a congested portion of the Medford Lakes Borough.  The dam, originally constructed in the 1920s, is an earthen embankment dam with a clay core. Between 2000 – 2001, a reconstruction project took place that included the creation of both a primary and auxiliary spillway and a concrete culvert. The primary spillway consists of a concrete dropbox and culvert that passes through the embankment. The auxiliary spillway, armored with articulated concrete block, is a low point on the embankment along Stokes Road.

In 2008, the Ballinger Lake Dam was inspected by Princeton Hydro and the NJDEP, Division of Dam Safety. The results of these inspections revealed considerable seepage at one of the concrete joints within the concrete culvert, a non-compliant trash rack assembly, a distressed gate valve assembly, and unstable downstream conditions. 

Under Princeton Hydro’s direction, the lake was lowered to reduce the hydraulic load on the dam and to facilitate the required remediation and repairs. Princeton Hydro provided full turn-key engineering services that encompassed the development of the engineering documents and plans and preparation of all the permitting requirements (NJDEP Dam Safety, Pinelands Commission Certificate of Filing (CoF), NJDEP Dam Safety Emergency Permit, Burlington County Soil Conservation Erosion and Sediment Control, and NPDES permits). Our team also prepared the contractor bid specifications and provided construction oversight and management throughout the course of the repairs.