The Passaic River

Credit: Jim Lukach

The Passaic River Watershed (below Millington Gorge) covers approximately 881 square miles.

Where It Starts

The main stem of the River begins at Millington Gorge in Long Hill Township, where the headwaters exit the Great Swamp National Wildlife Refuge.   

Where It Flows

The upper section of the River, after leaving the gorge, flows north-west between Long Hill Township and the Watchung Mountains, skirting the lower edge of the Great Swamp Watershed.  It passes through Long Hill Township, Berkeley Heights, and Summit before passing under Route 124 at the border of Chatham Borough and Millburn.  As it passes through Millburn, some of the River waters, along with water from Canoe Brook which joins the Passaic at this point, are used to fill the Canoe Brook Reservoirs 1 and 2, which provide water to South Orange and other communities.  As it leaves Milburn, the river heads north and forms the border between Livingston, Florham Park, and East Hanover. It then, seasonally, contributes to the water supply of the third Canoe Brook Reservoir.  

The river continues north and forms the border of Passaic and Essex counties. It is joined by two major tributaries, the Whippany River and the Rockaway River, where East Hanover, Montville, and West Caldwell meet.  It then flows north and east through Great Piece Meadows, a beautiful preserved floodplain that is often inundated with the overflowing waters of the River in the spring and during storm events. As it leaves Great Piece Meadows, it is joined by another major tributary, the Pompton River, at the border of Wayne and Lincoln Park.

The Central Passaic River begins as it enters Little Falls.  The river continues north and enters Paterson, flowing over the majestic Great Falls.  Shortly after the falls, the river finally makes a turn south along the eastern border of Paterson.  It then forms the border between Clifton on the west bank and Garfield on the east bank.  This area is called Dundee Lake and ends at the Dundee Dam.

The Lower Passaic River flows 17 miles from the Dundee Dam to Newark Bay, and is a tidal river.  The depth of the river in this section can fluctuate as much as three feet on a normal day, with much more extreme fluctuations during storm events.  The river mostly flows south from Paterson to Kearny with one major bend just south of the Saddle River confluence between Saddle River and Passaic.  It is joined by the Third River, which flows through Nutley and Passaic, entering the Passaic River at the border between the two towns.  As the river flows out of Belleville and into Newark it is joined by the last major tributary, the Second River. The river ends as it enters Newark Bay, with Newark on the west and Kearny on the east.

Notable Features of the Passaic River

The River has many beautiful parks and access points along its length (things to see and do) and provides habitat for a multitude of birds and animals.

The Morris Canal, which was a 107 mile historical canal that connected Pennsylvania’s Lehigh Valley to Northern New Jersey, crossed the River at a number of locations in Little Falls and Newark.  The Morris Canal Greenway project has established walking trails along the path of the canal that border the River in Little Falls.

The Great Falls in Paterson, which were named a National Historical Park in 2009, provide a beautiful vista along the river.

The Dundee Dam, spanning the River from Garfield to Clifton, marks the delineation between the upstream freshwater system and the downstream tidal portion of the river.  This 17 mile stretch of the river is the location of a federal Superfund site, caused by contamination in the 1950’s and 1960’s by Diamond Alkali and other corporations after the production of DDT and Agent Orange. The EPA finalized the Passaic River cleanup plan in 2016.

There are more than ten reservoirs located within the Passaic River Watershed, many of which divert flow at various times of the year both from and into the River.  There are also three major drinking water facilities that draw water from the River directly.  Overall, more than two million people get their drinking water from the River.

Problems/Water Quality

In 2017, GSWA began our expanded water quality monitoring along the River.  This expansion includes four water chemistry sampling sites on the River downstream of Millington Gorge between Long Hill and Summit.  We have also initiated visual assessments at multiple downstream locations.  Further downstream, we are looking forward to working with other groups to collect and assess water quality issues.

The downstream portions of the river are impacted by heavy development and increased areas of impervious cover, which can compound issues arising from flooding and runoff.  Below Dundee Dam both the water and the sediment are seriously impaired from the contamination of dioxin, PHA, and PCBs.  The tidal flow in this area of the river moves the sediment and makes clean-up efforts challenging.