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Peapack Brook Subwatershed Project (319 Grant)
Contents
- Project Area
- Project Area Conditions
- Project Summary
- Peapack Brook Restoration Update
- Land Owner's Guide
- GIS Report for Peapack Brook Subwatershed
- Monitoring Report
Project Area
The Upper Raritan Watershed, located in north central New Jersey, is defined by the drainage basin of the North Branch of the Raritan River. Within this geographic area lies the subwatershed of Peapack Brook, a significant tributary to the North Branch. This trout production stream flows through portions of both Morris and Somerset Counties as it courses through the Borough of Chester, Chester Township, the Borough of Peapack-Gladstone, and Bedminster Township. Including its tributaries, Peapack Brook continues for 22 miles from its headwaters to its effluence into the North Branch of the Raritan River in Bedminster.
Within the subwatershed, the drainage of which encompasses 11.7 square miles, land use varies. The headwaters of the brook originate at the Chester Springs Shopping Center in Chester Borough. Through Chester Township, the stream corridor and its tributaries are wooded, while the surrounding area supports residential development. As the brook flows into Gladstone, it courses through open fields, including the grounds and athletic fields of the Gill St. Bernard's School, abandoned agricultural fields, and those actively farmed. While the stream flows through a commercial and residential area in Peapack and Gladstone, the brook enters a wooded residential area once again in Bedminster. Project Area Conditions
Despite these relatively rural characteristics, the subwatershed suffers from several problems, including physical degradation of ecosystems and non-point source pollution. Many stretches of Peapack Brook lack woody vegetation along the stream banks to shade the water and maintain the low temperatures necessary to support a breeding population of native trout. The absence of trees also exacerbates erosion as the banks lack stability. Soil that is deposited into the stream is detrimental to the reproduction of both macroinvertebrates (aquatic insects) and native trout populations. Past studies have noted that soil erosion in this subwatershed may also have an impact on the North Branch of the Raritan River as soil that is lost from this subwatershed may travel to the Raritan River before it is deposited.
Sedimentation and contamination of the waterway is further attributed to increasing development. While the area of urban land has increased, the forest cover has significantly decreased in the subwatershed. While declines in macroinvertebrate diversity as well as trout abundance and recruitment have been correlated to increasing impervious cover, the replacement of natural vegetative cover with impervious surfaces has also augmented the amount of runoff that reaches the brook from commercial and residential areas.
In addition to the non-point source pollution attributed to such runoff, the Peapack Brook is also impacted by domestic livestock that have unrestricted access to the stream. Aside from the fact that these animals compact and erode stream banks, their waste contributes to high fecal coliform and nutrient levels in the water. Past studies have also detected warm temperatures and low quantities of dissolved oxygen in summer months.
Despite early evidence of degradation, no actions have significantly addressed these issues, and decades later the water quality in the Peapack Brook subwatershed still remains threatened, although Peapack Brook has been designated "non-impaired" on the State 303d list. Considering that Peapack Brook is classified as a trout production Category 1 waterway, the stream and its population of breeding trout are significant ecological and recreational assets. Project Summary
In order to assess Peapack Brook's water quality and aquatic habitat degradation, the Upper Raritan Watershed Association (URWA) designed evaluations of the subwatershed conditions and solicited stakeholder input to engage local communities in the process. In order to evaluate water quality, analyze trends, and identify factors responsible for degradation, URWA established a biological and chemical monitoring program (see Report of Biological and Chemical Monitoring). Using Geographic Information System (GIS) technology, URWA also analyzed land use and hydrological factors to assess the environmental integrity of the subwatershed (see Peapack Brook Subwatershed GIS Analysis Report). Additional evaluations in the form of River Assessment Team (RAT) efforts and visual assessments performed during monitoring also provided data depicting the current condition of discrete locations along Peapack Brook.
In addition to designing evaluations to discern the nature of threats and impacts to the subwatershed, URWA identified goals for reducing non-point source pollution, protecting environmental integrity, and restoration. Initial project objectives included increasing public awareness and understanding of problems jeopardizing the Peapack Brook subwatershed as well as improving water quality protection by decreasing non-point source pollution. In order to achieve these goals, URWA and partners, such as the Natural Resource Conservation Service (NRCS) and North Jersey Resource Conservation & Development (RC&D), hosted educational programs and implemented Best Management Practices, including livestock exclusion and vegetative management. Riparian stabilization and fisheries projects were also performed to reduce erosion and sedimentation of Peapack Brook as well as address shading and buffer issues.
Many project components focused on the stretches of Peapack Brook in or near Rockabye Meadow Park in Gladstone, NJ. Set in a residential suburban neighborhood downstream of a new housing development and animal management areas, this section of the brook is significantly impacted by contaminated runoff, excessive flows during storm events that exacerbate erosion and sedimentation, and a lack of vegetation along the banks to stabilize them and shade the trout production waterway. The park is also a recreational site for fisherman, and protecting the habitat will preserve an existing designated use.
Peapack Brook Subwatershed
