Great Brook

Credit: Jim Lukach

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Great Brook arises in Morris Township and covers 13 square miles.  

Where It Starts

Great Brook begins as four separate tributaries.  The two unnamed main stems originate in Morris Township, one within Spring Brook Country Club and the other near Footes Pond.  The other two tributaries, Silver Brook (which flows through our Conservation Management Area) and Bayne Brook, flow through Harding Township before they all converge east of James Street in Harding to form the main stem of Great Brook proper.

Where It Flows

Silver Brook, a main tributary, begins along Route 202 in Morristown before it flows through GSWA’s 53-acre Conservation Management Area (CMA) located on Tiger Lily Lane in Harding Township. As it leaves the CMA, it traverses one of the watershed’s most ecologically diverse areas, including a section of wetlands, mature forests, and meadows with an abundance of wildlife.

Bayne Brook, the other main tributary, flows through Bayne Park, where GSWA has worked with Harding Township to improve water quality by creating vegetated buffers around Bayne Pond, thus helping to reduce the impacts of non-point source pollution from that area.  The tributaries all converge east of James Street in Harding Township before flowing into Silver Lake just north of Blue Mill Road.

Great Brook is completely impounded at Silver Lake, the water then exits the lake via the spillway, which prevents sediment from building up in the stream and helps to aerate the water (increasing dissolved oxygen levels).

Once all of the tributaries converge in Harding Township, Great Brook flows through the Great Swamp National Wildlife Refuge, before merging with the Passaic River.

Notable Features

Silver Brook, one of Great Brook’s main tributaries, flows through our Conservation Management Area. If you follow the blue trail at the CMA, you will walk alongside scenic areas of the Silver Brook.

Problems/Water Quality

As it flows through developments near Footes Pond in Morris Township and Spring Brook Golf Course, Great Brook picks up non-point source pollutants, such as fertilizer and herbicides, carrying them into the Great Swamp National Wildlife Refuge.

Our most recent water quality monitoring results show that Great Brook’s waters are moderately impaired. While the subwatershed does contain a mix of forest (26%) and wetlands (24%), 40% of the land is developed, with a majority of that development located around Great Brook’s headwaters.

For Great Brook’s water quality to improve, there needs to be a focus on smart development and improved stream buffers in already developed headwaters. Sensitive and critical undeveloped downstream areas also need to be proactively protected.  

GSWA has worked with Morris County Park Commission on a number of projects to help clean upstream areas and improve buffer zones.  One continuing project has been our participation in Morristown Parks and Ponds Day, where we have worked with volunteers to clean up the area around Footes Pond, removing trash and invasive plant species.

The 2015 Great Swamp Water Quality Report Card showed improvements in overall macroinvertebrate communities in Great Brook as well as a significant improvement in the bacteria levels.  However, road salt from the developed areas continues to be a problem, and some increases were seen in sedimentation and nutrient levels.

How You Can Help

Great Brook faces many problems, below are ways you can help:

  • Increased sediment and erosion: Planting native multi-stemmed plants such as shrubs at the bottom of sloped areas in your lawn can help reduce runoff speed and nutrient levels in the runoff. Also, breaking up large areas of mowed lawn with small gardens containing native plants can help.
  • Road Salt: Use road salt only when necessary and consider using alternative compounds that are more environmentally friendly such as Calcium Magnesium Acetate (which is also pet friendly).
  • High bacteria levels: Pick up after pets, even in the yard, and be sure to maintain septic tanks regularly.