Post Construction

As areas are developed, the amount of paved surfaces increase leading to an increase in stormwater volume and pollutants, which can harm our streams.

The best way to mitigate stormwater impacts from new development is to use practices that treat, store, and infiltrate runoff onsite before it can affect water bodies downstream. Innovative site designs that reduce paved surfaces, or imperviousness, and other green infrastructure practices are excellent ways to reduce flows and improve water quality.

In partnership with the Dauphin County Conservation District, and in association with our MS4 permit, Londonderry Township has a program to address post-construction stormwater runoff from new development and redevelopments that disturb one or more acres.

The program includes:

• strategies to implement a combination of structural and non-structural BMPs,

• an ordinance to address post-construction runoff, and

• a program to ensure adequate long-term operation and maintenance of BMPs.

Download Londonderry Township's Plan for Post-Construction Stormwater Management in New and Redevelopment
Reviewed 4/4/2024. Revised 1/8/2021.

Rain Garden	Constructed Wetland
Detention Basin with Retention Area	Infiltration Trench
Dry Swale