MCM#5 - Post-Construction Stormwater Management

MCM#5 focuses on constructing stormwater management facilities during new and redevelopment projects in the Township to mitigate the adverse effects of increased stormwater volume and pollutants resulting from development. As areas are developed, the rise in paved surfaces exacerbates stormwater runoff, posing risks to our streams and water bodies. To address this, the Township has enacted a Post-Construction Stormwater Management (PCSM) Best Management Practices (BMPs) ordinance, mandating the implementation and adherence to PCSM BMPs. Additionally, the Township encourages the use of Low Impact Development (LID) practices in new and redevelopment projects. Proper construction and adherence to the Operations and Maintenance (O&M) plans of PCSM BMPs and LIDs are crucial to their effectiveness.

Mitigating Stormwater Impacts
Increasing paved surfaces in developed areas escalates stormwater volume and pollutants, posing threats to lakes, rivers, streams, and coastal areas. Employing practices that treat, store, and infiltrate runoff onsite before reaching downstream water bodies is paramount. Innovative site designs that reduce impervious surfaces and incorporate green infrastructure practices are effective in minimizing flows and improving water quality.

Program Implementation and Requirements
In collaboration with the Dauphin County Conservation District and in alignment with our MS4 permit, Lower Swatara Township has established a program to address post-construction stormwater runoff from new developments and redevelopments disturbing one or more acres. This program includes:

• Implementation of a combination of structural and non-structural BMPs to manage stormwater runoff
• Enactment of an ordinance to regulate post-construction runoff
• Establishment of a program to ensure proper long-term operation and maintenance of BMPs

Inspection Program and Compliance
Lower Swatara Township is mandated by the Pennsylvania Department of Environmental Protection to establish an inspection program for various stormwater features, including grass swales, infiltration trenches/seepage pits, rain gardens, and stormwater basins. Inspection of these features is integral to the Township's Municipal Separate Storm Sewer System (MS4) Permit program, and residents may receive notices from the Township indicating the functionality of their stormwater BMPs. Cooperation with Township staff is appreciated during this process.

Through MCM#5, Lower Swatara Township is committed to implementing robust stormwater management practices to safeguard our water resources and promote sustainable development within our community.