WMA 10: Millstone

[The following information has been adapted from resources developed by the NJ Dept. of Environmental Protection Division of Watershed Management.]

WMA 10 HighlightWMA 10 is a 265 sq. mile watershed that encompasses parts of five counties (Hunterdon, Somerset, Middlesex, Mercer and Monmouth) and twenty five towns. It is fed by the Stony Brook and other small streams, and is a major tributary to the Raritan River.

The Millstone Watershed spans both the Piedmont physiographic region to the north and the Coastal Plain to the south. Land use in this area is primarily suburban development with agricultural lands scattered throughout. The region is also home to sensitive ecological features like the Sourland Mountains, which is the largest contiguous forest in central Jersey, and the Princeton Ridge.

The Millstone River is 38 miles long and flows from Millstone Township in Monmouth County to the Raritan River near Manville and Bound Brook. Major tributaries include the Stony Brook, Cranbury Brook, Bear Brook, Ten Mile River, Six Mile River and Bedens Brook and the largest impoundment is Carnegie Lake. For nearly three quarters of its length, the Millstone is paralleled by the Delaware & Raritan Canal. Both waterways provide significant sources of recreation and drinking water to the residents of central New Jersey.

Land use in the Millstone Watershed is primarily suburban development with scattered agricultural areas although there is extensive, recent development present in the upper portion. Nonpoint source pollution from lawn fertilizers, animal waste, and other contaminants are carried into local waterways by stormwater runoff and have decreased water quality in some areas. Flooding is also a major issues in some areas of the watershed, like the Borough of Manville.

Watershed Groups and Allies in the Region:

Friends of Hopewell Valley Open Space
Friends of Princeton Open Space
Sourland Conservancy
Stony Brook-Millstone Watershed Association