green stormwater infrastructure

Stormwater Management

Best practices for stormwater management

The City of Philadelphia has a combined sewer system, meaning that a single pipe carries stormwater from streets and wastewater from houses and businesses. When flow in the sewer increases as a result of rainfall or snowmelt, the sewer pipes or treatment plants may reach their capacity, resulting in a combined sewer overflow (CSO). When this happens, the EPA permits Philadelphia, as it does with other cities with combined sewer systems, to discharge excess wastewater into nearby water bodies to prevent health and human safety issues that may result from localized flooding in neighborhoods and in water treatment plants.

In accordance with Philadelphia Water Department requirements, campus buildings and landscapes are increasingly being designed to prevent stormwater from overwhelming the city’s sewer system. Water conservation, as well as lush rain gardens & green roofs are welcome side benefits of these stormwater management practices.

A few highlights of stormwater management practices on campus include:

  • Shoemaker Green – contains an underground cistern capable of holding 20,000 gallons of water, as well as a rain garden planted with native trees and other vegetation to allow for stormwater to drain slowly into the soil 
  • Penn Park – contains a cistern with a 300,000-gallon capacity so stored rainwater can later be used for irrigation, as well as 6 acres of native grass meadows to help divert stormwater from the sewer system.

Read more about stormwater management on campus in this Penn Today article. 

Stormwater Master Plan

In 2013, Penn completed a comprehensive Stormwater Management Master Plan for the campus. The Plan included an assessment of all pervious, impervious, and landscaped surfaces on campus and provided an estimate of total stormwater generated within Penn’s 300-acre landscape. The plan provided site-specific examples of best practices for stormwater management, including cisterns, bioswales, rain gardens, green roofs, and permeable paving. The Master Plan also includes an Operations and Maintenance Manual for existing stormwater management systems on campus.