Stormwater Management & MS4

What is Stormwater Runoff?

Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground. Impervious surfaces like driveways, sidewalks, and streets prevent stormwater runoff from naturally soaking into the ground.

Why is Stormwater Runoff a Problem?

Stormwater can pick up debris, chemicals, dirt and other pollutants and flow into a storm sewer system or directly into a lake, stream, river, wetland, or costal water, untreated.

What is MS4?

A Municipal Separate Storm Sewer System (MS4) is a conveyance or system of conveyances that is owned by a municipality, designed or used, to collect or convey stormwater.

To learn more about Stormwater, follow the links below for external resources:

• How to Be Stormwater Smart by DEP

• The Homeowner's Guide to Storm Water by Penn State College of Agricultural Sciences

• Learn about NPDES (National Pollutant Discharge Elimination System) permits and the general MS4 Program

• Activity booklet for children to learn about stormwater

• Roadside Guide for Clean Water

To learn more about Londonderry Township's Stormwater Management Program explore the left hand navigation barnavigation above.