To reduce flooding impacts, many construction codes require the installation of stormwater basins to retain and delay the discharge of stormwater runoff from new development. These basins are commonly seen in housing developments and at shopping centers. Retrofitting these basins can change the focus from retaining and delaying stormwater runoff to infiltration of stormwater and nutrient (pollutant) removal. Before retrofitting can occur, municipalities must have an accurate inventory of the basins within their municipality, including the type of basin, ownership, and the current condition (whether it functions as designed). Currently, New Jersey Discharge Elimination System Municipal Stormwater General Permits require that certain municipalities (Tier A) map only the ends of outfall pipes.

The New Jersey Hydrologic Modeling Database contains a compilation of stormwater basins as collected by the NJ Soil Conservation Districts and the New Jersey Department of Agriculture. Along with location data, this database includes site and design data, images of site plans (where available), current basin conditions, and written documents such as operation and maintenance plans.

To assist with the outfall pipe mapping, the DEP developed a free stormwater facility mapping application. This application provides a method for municipalities and/or partners to easily create a detailed inventory and map of stormwater facilities. Information captured by the application includes data on outfall pipes, stormwater management basins, subsurface infiltration/detention systems, manufactured treatment devices, green infrastructure, and storm drain inlets. Information also includes photographs and inspection notes, such as facility condition, maintenance activity, date of inspection, and evidence of flooding. DEP, along with our AmeriCorps New Jersey Watershed Ambassadors Program, will identify volunteer municipalities to implement use of the application to identify and inventory stormwater basins.

• Action: Identify municipalities and perform inventory utilizing new application


• Lead: AmeriCorps New Jersey Watershed Ambassadors Program


• Partners: DEP – Division of Water Monitoring and Standards, Division of Water Quality, and Municipal stakeholders


• Progress: $325,000 Water Quality Restoration Grant to perform 10-15 low cost stormwater basin retrofits in Lakewood Township which will implement the Metedeconk Watershed Protection and Restoration Plan. Funding awarded to South Jersey Resource Conservation and Development Council in state fiscal year 2018.