H&H provided engineering services and construction support services for Newton Lake Dam spillway replacement project. H&H provided the structural design for the replacement of dam spillway, outlet works, and the re-decking of the bridge, as well as dam safety and environmental permitting services.
Newton Lake, an 80-acre recreational facility owned by Camden County, is comprised of an earth fill embankment approximately 200 feet in length with a top width of about 80 feet increasing to about 120 feet wide at the bottom. The total watershed area contributing flow to Newton Lake Dam is about 5.01 square miles. Of that area, discharge from approximately 4.01 square miles is conveyed by Newton Creek to the dam and spillway.
The dam spillway will be replaced with an ogee style spillway with increased capacity, improved freeboard conditions, drawdown capability, and accommodation of a fish ladder. The design team recognized opportunities to mitigate traffic congestion during construction, optimizing signal capacity which offered an opportunity to use larger work zones.
NJ Route 168, a four-lane paved roadway, is carried along the crest of the embankment of Newton Lake Dam. The existing deck consists of approximately 20” thick cast-in-place concrete slab beams, therefore, the bridge will require full superstructure replacement. Due to the staging pattern associated with re-decking, the existing islands will be paved during construction and then returned to their original configuration after construction. The final design corrects substandard geometrics. Traffic signal reconstruction is required and accomplished in stages.