Major work completed at NJ's largest reservoir, but when will it regain normal levels?
CLINTON TOWNSHIP – With the major earthwork completed in the Round Valley Reservoir modernization project, the New Jersey Water Supply Authority (NJWSA) will start pumping water to refill the reservoir.
The state's largest reservoir is at 66.4% of its 36.51-billion-gallon capacity, according to the NJWASA. The water level needs to rise by 25 feet.
During the project the reservoir reached a low of 55.6% of capacity in October 2022.
Nearby Spruce Run Reservoir is at 96.7% of capacity.
The NJSWA estimates that it will take one to three years to complete to the refilling.
The water for the reservoir is pumped from the South Branch of the Raritan River.
How much water is pumped from the river depends on the flow in the state's longest river, according to the NJSWA.
The flow in the river must be high enough to provide excess water for the reservoir while also meeting demand downstream, including New Jersey American Water at the confluence of the Raritan and Millstone rivers.
Spring has been the primary season for pumping water from the river into the reservoir, but the NJWSA says it will pump during autumn and winter if conditions allow.
According to the NJWSA, work at the dike – the dam crossed by Hunterdon County Route 629 – is "substantially complete."
Restoration work continues at the North Dam – the dam facing Lebanon Borough – to return the embankment and surrounding areas to preconstruction conditions. The current work includes paving, topsoil and seeding, decommissioning soil erosion and sediment control measures.
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Major earthwork at the South Dam – the dam facing Molasses Hill Road – was completed in August. The next major items of work are topsoil and seeding, installation of turf reinforcement matting, decommissioning of sediment basins, installation of dam instrumentation and paving.
The NJWSA is making improvements to the reservoir, more than a half-century old, to extend its operating life as a critical source of drinking water and increase its durability for years to come.
The project calls for the top layers of each dam to be pulled away and then replaced, with new filter material (sand, gravel) placed inside, according to the NJWSA.
Reaching depths of 180 feet, the 2,350-acre reservoir is known for its clear blue waters and good fishing.
Email: mdeak@mycentraljersey.com
Mike Deak is a reporter for mycentraljersey.com. To get unlimited access to his articles on Somerset and Hunterdon counties, please subscribe or activate your digital account today.
This article originally appeared on MyCentralJersey.com: Round Valley Reservoir could take three years to refill, NJ says
