Stormwater Management

Welcome to the Radnor Township Stormwater Management Information page.  This page is designed to provide Township residents and businesses with access to information, tools and resources to help preserve and protect clean water in the Township.  We hope that you will find this information useful.

Please remember that both residents and businesses also have an opportunity to help, which when combined together will have a positive impact on our environment and the water that is so important to us all.

For more information on the State of Pennsylvania stormwater management please visit the PA DEP website: Pennsylvania Department of Environmental Protection. 

What is Stormwater?
Stormwater is rainwater and melted snow that runs off streets, lawns, and other sites. When stormwater is absorbed into the ground, it is filtered and ultimately replenishes aquifers or flows into streams and rivers.  Stormwater becomes a problem when it picks up debris, chemicals, dirt and other pollutants as it flows or when it causes flooding and erosion of stream banks.

In developed areas, however, impervious surfaces such as pavement and roofs prevent precipitation from naturally soaking into the ground. Instead, the water runs rapidly into storm drains, sewer systems, and drainage ditches and can cause:

  • Downstream flooding
  • Stream bank erosion
  • Reduced water quality
  • Changes in the flow rate of a stream
  • Infrastructure damage
  • Contaminated streams and rivers
Stormwater travels through a system of pipes and roadside ditches that make up stormwater systems.  It eventually flows directly to a lake, river, stream, wetland, or coastal water.  All of the pollutants stormwater carries along the way empty into our waters, too, because stormwater does not get treated.
Like many Pennsylvania communities, Radnor is faced with a range of stormwater management challenges from increasing federal and state regulation to aging and undersized infrastructure. Depending on where you live in Radnor you may or may not have been directly impacted by these events, but you likely know someone who has been. Some of the stormwater challenges the township is currently facing include:

  • Increased occurrence of flooding.
  • Infrastructure installed prior to modern standards, or not at all.
  • Storm sewer which is beyond its expected design life.
  • $10 million backlog of known stormwater-related capital improvement projects and no dedicated capital budget to fund these projects.
  • Additional regulatory responsibilities for the township's Municipal Separate Storm Sewer System (MS4) permit requirements under the federal Clean Water Act.