Understanding the Importance of Stormwater Management

Above, stormwater sites at different phases of development.

Due to the rapid rate of development, Philadelphia is losing its open, green spaces. As a result, stormwater that was once naturally absorbed into the ground now passes over manmade surfaces like rooftops and roadways; picking up contaminants before making its way to the sewers. The city’s antiquated sewer system is ill-equipped to transport the considerable surges of stormwater brought about by heavy rains. Overflows have been detected in nearly 200 locations, causing polluted water to commingle with the rivers and streams. Remedying this non-point source pollution relies upon keeping as much of this runoff out of the sewers as possible.

But how? Perhaps the most obvious answer is to modernize the sewer system, but such an undertaking is sure to be inconvenient and would take years to complete. If nothing else, the expense put upon taxpayers would be staggering.

As an alternative, Philadelphia Green has joined forces with the Philadelphia Water Department to minimize polluted stormwater runoff through “low impact development” or LID, an innovative approach that seeks to detain, filter, and infiltrate runoff by mimicking natural processes. By relying more on landscaping than on infrastructure, this approach works hand-in-hand with efforts to create and enhance open space in urban neighborhoods. Funding for this project comes courtesy of the Pennsylvania Department of Environmental Protection.