Catalyzing Investment in Urban Sustainability
U.S.-Brazil Joint Initiative on
Urban Sustainability


Stormwater Utility Rate Structuring

Policy Overview

As Philadelphia's stormwater management costs increase, it has become more important to the City to receive payment for providing stormwater service. Historically, the charge for municipal stormwater service has been based on the volume of drinking water being used by a property, which is often not representative of true stormwater costs and results in losses for the City. Since July 1, 2010, the charges for nonresidential and condominium properties have been based on the total size of the property and the amount of impervious surface. This allows for a more accurate assessment since the new method accounts for a property's effect on the stormwater system in calculating stormwater fees. However, this method has resulted in new fees for properties that historically did not pay for stormwater, such as parking lots and other properties without water or sewer service. To lessen the burden on customers like these, Philadelphia Water Department (PWD) is phasing in the new charge over a period of four years and offering a stormwater credit program. Credits provide an opportunity for property owners to reduce the cost of their stormwater fees by using green infrastructure techniques that limit impervious cover and reduce the amount of runoff generated.

How to Apply this Policy

Municipalities or public utilities that are seeking to account for the true cost of stormwater management may want to develop parcel-based fee systems like Philadelphia's. In order to develop its new stormwater billing system, the Philadelphia Water Department inventoried parcel size and parcel ownership, including land deeds, to create a number of data layers in Geographic Information Systems software that reflect the contribution of individual parcels to stormwater runoff. Under the new fee system, nonresidential and condominium properties will be charged based on the "Gross Area," or total size of the property, and the "Impervious Area," which can include rooftops, concrete, asphalt, or any other surface where rainwater becomes polluted, runs off into storm drains, and burdens the City's sewer system.

Contact Information
Phone: +1 (215) 685-6143 or +1 (215) 685-4935

Seattle Public Utilities-Stormwater Facility Credit

Seattle Public Utilities developed a similar program, the Stormwater Facility Credit Program, to acknowledge privately owned systems that reduce stormwater flow and/or provide water quality treatment, which help lessen the impacts of stormwater.