The Spruce Run Reservoir is located in Hunterdon County, New Jersey and became operational in 1963. The 11 billion gallon on-stream water storage reservoir includes a 6,000 foot long earthen dam and two earthen dikes.

The Spruce Run Reservoir is an integral part of a water supply system that also consists of Round Valley Reservoir and the Delaware & Raritan Canal Transmission Complex which together have the capability of delivering 225 million gallons of raw water per day to the water utilities that serve central New Jersey.