Stormwater management on residential properties plays a critical role in protecting the quality of stream and groundwater resources and preventing damage to neighboring properties. The County-wide Act 167 Stormwater Management Plan contains a model stormwater management ordinance (adopted by all 67 Chester County municipalities) designed to promote sound stormwater management on all types of new development and redevelopment activities across the County. This plan and its model ordinance assists municipalities in implementing integrated stormwater management that effectively controls runoff, limits flooding, reduces streambank erosion, and promotes groundwater infiltration to maintain or improve the water quality of the County’s streams.
Much of the new development that occurs in Chester County includes the construction of new residential properties and modifications to existing residential properties. To ensure comprehensive and consistent stormwater management across the County, the model ordinance includes provisions that apply to residential, commercial, and industrial projects alike. These provisions are designed to maximize stormwater infiltration and reduce increases in post-construction stormwater runoff to prevent damage to adjacent properties and to improve water quality. This ordinance also includes provisions that protect natural features, including natural hydrology, wetlands, stream corridors, and riparian areas.
Residents should consult their municipality if they are preparing to complete a project that may result in over 1,000 square feet of new impervious surfaces or will include greater than 5,000 square feet of earth disturbance. By incorporating stormwater best management practices into the site designs, residents can reduce their runoff footprint and prevent additional untreated runoff from flowing onto neighboring properties and into local streams. Small residential projects that will result in less than 1,000 square feet of new impervious area and less than 5,000 square feet of earth disturbance are exempt from many of the ordinance provisions. While specific stormwater management actions may not be required for smaller projects, implementing practices such as a rain barrel or small rain garden is encouraged to help manage any additional stormwater runoff. For more ideas of ways you can improve stormwater management on your property, visit CWMP’s Homeowners Resources page.