Town guide · Somerset County
Living in Watchung, NJ
Watchung is a borough of about six square miles on the slopes of the Watchung Mountains in Somerset County. Stony Brook runs through town into Watchung Lake at the Watchung Circle, and Interstate 78 and Route 22 are both close at hand.
- County
- Somerset
- Population
- About 6,400 (2020 census)
- Size
- About 6 square miles
- Setting
- Suburban borough on the slopes of the Watchung Mountains
- Main roads
- Interstate 78 (Exit 41, with Exit 40 just over the line), U.S. Route 22, County Routes 527 and 531
First things first
Watchung the borough, Watchung the mountains
The Watchung name covers a lot of ground in central New Jersey. The Watchung Mountains are a pair of long ridges running through several counties. The Watchung Reservation is a Union County park in Summit, Mountainside, Berkeley Heights, Scotch Plains and Springfield, not in the borough.
Watchung Borough is its own municipality in Somerset County, formed in 1926 from part of North Plainfield Township, which is now Green Brook. When we price or search for a home, we always confirm the actual municipality, because that decides the tax rate and the town services.
Neighborhoods
A borough in the hills
Watchung borders Green Brook, North Plainfield and Warren Township in Somerset County, and Berkeley Heights, Plainfield and Scotch Plains in Union County. The name is said to come from the Lenape language for high hills. In early times the area was called Washingtonville, but the Postal Service turned that name down because New Jersey already had so many places named for Washington.
- The Watchung Circle: The traffic circle where Watchung Lake Park sits, with Valley Road leading off it to Best Lake.
- Washingtonville: An old unincorporated place name, partly inside the borough, from the area's early days.
- Along Stony Brook: The brook flows in from Warren, through Watchung Lake, then through a gorge in the First Watchung Mountain and over Wetumpka Falls toward Green Brook.
Homes
What you will find
- Single family homes: Detached houses across the slopes and valleys of the Watchung Mountains.
- Homes on septic: Some parts of the borough are served by private septic systems rather than public sewer.
Worth knowing: Not every Watchung home is on public sewer. Somerset County's septic management plan counts Watchung among the towns where part of the community uses onsite septic systems. We find out early whether each home is on sewer or septic, because it affects inspections, upkeep and the questions buyers ask.
Property taxes
What taxes look like in Watchung
- 2.031%2025 effective tax rate, as a share of market value
- $18,2792025 average residential tax bill
A home worth $900,000 on today's market would pay roughly $18,279 a year at Watchung's 2025 effective rate. Your actual bill depends on your assessment, so we pull the real tax record for any home you are considering.
Source: New Jersey Division of Taxation, 2025 general and effective tax rates. Rates are set each year.
Getting around
Roads and commuting
Interstate 78 runs through the northwestern part of the borough, with Exit 41 in Watchung toward Berkeley Heights and Scotch Plains, and Exit 40 at County Route 531 just over the line in Warren. U.S. Route 22 passes briefly through the southeast corner of the borough. County Route 527 (Mountain Boulevard and Valley Road) runs about 5.2 miles across the borough, and County Route 531 (Somerset Road and Hillcrest Road) connects North Plainfield to Interstate 78. There is no train station in Watchung. The closest NJ Transit stations are Plainfield, Netherwood and Fanwood on the Raritan Valley Line.
Places worth knowing
Parks, landmarks and open space
- Watchung Lake Park: A borough park at the Watchung Circle, on the lake fed by Stony Brook.
- Best Lake and Picnic Grove: A borough lake and picnic grove on Valley Road, just off the Watchung Circle.
- Mobus Field and Phillips Field Complex: The borough's athletic fields on Brookdale Road.
- Washington Rock State Park: A 52 acre state park next door in Green Brook, on the First Watchung Mountain ridge with the overlook General Washington used in 1777 to watch troop movements.
Common questions
Questions people ask us about Watchung
What are property taxes in Watchung, NJ?
Watchung Borough's 2025 effective tax rate is 2.031 percent of market value, and the average residential tax bill is $18,279, according to the New Jersey Division of Taxation. Actual bills depend on each home's assessment.
Is the Watchung Reservation in Watchung?
No. The Watchung Reservation is a Union County park of about 1,945 acres in Summit, Mountainside, Berkeley Heights, Scotch Plains and Springfield. Watchung Borough is a separate town in Somerset County.
Is there a train station in Watchung?
No. The closest NJ Transit stations are Plainfield, Netherwood and Fanwood on the Raritan Valley Line. Interstate 78 Exit 41 is in the borough, and Route 22 passes through its southeast corner.
Where does the name Watchung come from?
It is said to come from the Lenape language, meaning high hills. The area was called Washingtonville in early times, but the Postal Service rejected that name. The borough was formed in 1926 from part of North Plainfield Township.
Do Watchung homes have septic systems?
Some do. Many homes are on public sewer, but Somerset County's septic management plan lists Watchung among the towns where part of the community uses onsite septic systems. We confirm which a home has before it goes on the market.
Nearby towns
Towns that border Watchung
Buying or selling in Watchung?
Hills, slopes and septic
A home on a steep lot above Stony Brook and one near the Watchung Circle raise different questions at inspection. We check the slope, the sewer or septic setup and the street before we talk about price.
Call or text either of us directly.