The Round Valley Reservoir, with a capacity of 55 billion gallons, is the largest reservoir in the State of New Jersey. Constructed in the 1960s, it is retained by three earthen structures classified as High Hazard – Large Dams.


The rehabilitation project addresses issues with the large earthen structures including seepage, slope stability, and drainage. GZA is supporting the prime contractor, as the subcontractor for the installation of the Dam Instrumentation and Monitoring System (DIMS). To our knowledge, this is the largest and most complete dam instrumentation monitoring program in New Jersey and our local New Jersey staff is conducting this work.


GZA’s scope of work includes installation and modification of over 60 piezometers and 12 inclinometers, automating existing and newly constructed piezometers by installing up to 130 vibrating wire piezometer (VWP) transducers, abandoning/grouting over 90 existing piezometers, installing weir monitors and setting up an automated data acquisition system (ADAS) to monitor the dam during and after rehabilitation.



In addition to GZA’s strengths in dam engineering and instrumentation, GZA was able to draw from a large, qualified engineering staff to oversee the extensive field operations, coordinating closely with the rehabilitation team (Owner, Owner’s Engineer and Contractor), and our subcontractors (which included multiple drillers working concurrently) to accommodate an aggressive 24/7 excavation schedule on this project of unprecedented scale.