Why are Stormwater Regulations important?
The negative impacts of unmanaged stormwater runoff present a challenge to the City of Philadelphia, including increased pollution concentrations in local waterways, reduced groundwater levels, increased erosion, loss of aquatic habitats, increased flood frequency, and increased quantity, frequency, and duration of combined sewer overflows.
Philadelphia is also required by Federal and State law to manage stormwater runoff.
Federal and State Regulations
Clean Water Act - Passed by Congress in 1972, the Clean Water Act established water quality standards for surface water in the United States. The State enforces these standards by issuing permits that regulate combined sewer overflows and stormwater runoff in areas with separate sewer systems.
Pennsylvania Act 167 - Established in 1978, Act 167 requires counties to develop stormwater management plans for local watersheds. After the State approves the plans, municipalities implement them in part through ordinances that regulate land development. Philadelphia enforces several Act 167 plans that were developed in conjunction with bordering counties. Learn more about Act 167 Planning in Philadelphia at phillywatersheds.org.
To confront these challenges of stormwater runoff and to meet our regulatory requirements, the Philadelphia Water Department developed regulations that ensure a modern and effective stormwater management program.
What are the Philadelphia Water Department Stormwater Regulations?
All development projects that disturb more than 15,000 square feet of earth (5,000 square feet in certain watersheds) must meet PWD’s Stormwater Regulations. The Stormwater Regulations have four main components: Water Quality, Channel Protection, Flood Control, and Public Health and Safety Release Rate requirements.
Water Quality: Remove pollutants from stormwater and reduce the volume of water entering sewers. This is achieved by letting the water soak into the ground or through a stormwater management practice.
Channel Protection: Protect stream banks by minimizing the rate of erosion from stormwater runoff.
Flood Control: Manage the rate of runoff from a property to prevent localized flooding.
Public Health and Safety Release Rate: Manage the rate of runoff from a site located in an area where known flooding has occurred due to constraints in the sewer network.
Effective July 1, 2015, the Philadelphia Water Department updated its Stormwater Regulations for private development. The changes will improve the health of Philadelphia’s rivers, minimize local flooding, and encourage the use of green infrastructure throughout the city. Find more information about the update here.
Detailed information regarding the Stormwater Regulations can be found within Chapter 6, Stormwater Management, of PWD’s Regulations.
How do the PWD Stormwater Regulations affect my project?
For information on how the PWD Stormwater Regulations are applied to private development projects, please refer to Chapter 1 of the PWD Stormwater Manual.