About Spruce Run Reservoir

Spruce Run Reservoir is the third-largest reservoir in New Jersey, after Round Valley and Wanaque. It covers 1,290 acres of water with 15 miles of shoreline open for recreation, in the rolling hills of Hunterdon County near Clinton. The reservoir went into service in 1963 and holds up to 11 billion gallons behind a 6,000-foot earthen dam. Spruce Run Recreation Area, run by the NJDEP State Park Service, was dedicated in 1973.

How the Reservoir Was Built

New Jersey built Spruce Run after a historic drought. To meet a growing need for water and for places to play outdoors, the Legislature passed the 1958 Water Supply Law and its companion Water Bond Act, which treated water as a natural resource to be conserved and managed. Spruce Run Reservoir was one of the first water supply facilities the state built and ran itself. The New Jersey Water Supply Authority dates its start of operations to 1963. The recreation area around it was then developed and dedicated in 1973.

Who Runs What

Two state bodies share Spruce Run:

• The New Jersey Water Supply Authority operates the reservoir and its dam as a source of raw drinking water. Created in 1981, the Authority is "in but not of" the NJ Department of Environmental Protection, and the NJDEP Commissioner chairs its board.
• The NJDEP State Park Service manages the recreation: the campground, picnic areas, boat launch, trails and the beach area.

Because the reservoir is a water supply first, its level moves with rainfall and with demand for drinking water downstream.

Where the Water Goes

Spruce Run is an "on-stream" reservoir, fed entirely by rain that flows in through several streams, chiefly the Spruce Run and Mulhockaway Creek. Its watershed covers 41 square miles across parts of five municipalities. Each day water is released back into the Spruce Run, which joins the South Branch of the Raritan River in the Town of Clinton. Downstream, the North and South Branches meet in Branchburg to form the Raritan River, where water companies draw and treat it for central New Jersey.

Spruce Run works as one system with Round Valley Reservoir and the Delaware and Raritan Canal. Together they can deliver 241 million gallons of raw water a day to the utilities that serve central New Jersey.

Round Valley Is a Separate Park

Round Valley Reservoir, also in Hunterdon County, is its own state recreation area with its own entrance, fees and rules, and isn't covered on this site. It is an off-stream reservoir of 55 billion gallons, filled mostly by pumping water from the South Branch of the Raritan. The one rule both reservoirs share is the 25 mph wind closure for boats (boat launch).

Wildlife and Programs

A wildlife observation blind near the boat launch is a good place to watch nesting songbirds and migrating waterfowl. NJDEP publishes a list of common mammals and one of common songbirds for Spruce Run, Voorhees and Hacklebarney State Parks. Park staff run historical and natural programs through the year; contact the park office for the schedule and to register. Some programs have a fee.

Accessibility

NJDEP describes Spruce Run's facilities as partially accessible for people with disabilities. Call the park office at 908-638-8572 about specific needs. TTY users can reach it through NJ Relay at 711.