Azavea Creates the Web-Based System to Support the Philadelphia Water Department’s New Green Stormwater Management Program

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Azavea (formerly Avencia), an award-winning Geographic Information Systems (GIS) software design and development firm, announces the launch of, a public web Stormwater Billing application ( for the Philadelphia Water Department (PWD). The application supports the City of Philadelphia’s new parcel-based stormwater billing program.

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Azavea, an award-winning Geographic Information Systems (GIS) software design and development firm, announces the launch of, a public web Stormwater Billing application ( for the Philadelphia Water Department (PWD). The application supports the City of Philadelphia’s new parcel-based stormwater billing program.

On July 1, 2010, the City of Philadelphia flipped the switch on a new approach to assessing stormwater management fees that has been under development for over 15 years. As a consequence, a new billing system is now in place. Under the new billing methodology, which will gradually be phased in over the next 3 years, non-residential property owners will be charged for stormwater based on the total area of their property and the amount of impervious surfaces on their property, rather than being based on the amount of water they use. The system, developed by Azavea, enables property owners to understand how PWD calculates their new stormwater charges, detailing how each component of the stormwater charge was calculated, how it will be phased in over time, and what steps the property owner can take to reduce their charges through a credits program for each onsite water management practice they decide to implement. The application enables property owners to visualize their property in a high resolution aerial photography and display the following data:

  • Impervious area of their property
  • Gross area of their property
  • PWD account information
  • Credits associated with the account
  • Charge summary from FY 2011 to FY 2014

Customers who want to dispute the gross area or impervious area of their parcel can submit appeals, which are researched and in turn, managed by the PDW staff members through the application.

Why is the City of Philadelphia’s new stormwater management program such a significant move and why can it be qualified as “green”? As a city grows and its open spaces are covered with concrete, asphalt and rooftops, stormwater that might have once been naturally filtered and absorbed by vegetation and soil is collected by the municipal stormwater system. In many older cities, the stormwater and the sanitary sewer are combined into a single system. When there is a storm event, the system outstrips the filtering capacity and the extra runoff overflows into the rivers, creating significant environmental and health impacts. The more impervious surface -- parking lots, sidewalks and roofs – the more rapidly and frequently the runoff will result in a combined sewer overflow (CSO) event. Most municipalities remediate this issue by building more and larger infrastructure, but for a city the age and size of Philadelphia, this would carry a very large price tag. The Philadelphia Water Department has decided to implement a billing system that aims to encourage property owners to use onsite green management practices such as retention basins, trees, green roofs and porous pavement in order to both reduce the amount of impervious pavement and use soil and vegetation to filter the water. They hope this new approach will be more environmentally-friendly, lower cost, and easier to manage. In addition, PWD has also created a program of credits that incentivize owners to retrofit their properties with onsite stormwater management practices, thus reducing their stormwater fees.

Philadelphia’s approach is not unique -- Portland, Oregon has implemented a similar sustainable stormwater management system -- but Philadelphia’s program is the largest and most ambitious green stormwater management program in the country. By 2029, PWD plans to replace at least one third of the City's impervious surfaces with green stormwater infrastructure. Already a national leader in the design and construction of green roofs and other urban sustainability practices, the new program is part of Philadelphia’s Greenworks Program, an ambitious plan to transform Philadelphia into the greenest city in the U.S. By committing the city to managing stormwater with green infrastructure, PWD also aims to increase recreational opportunities, provide jobs, and improve air quality.

“As a B Corporation, we seek out projects that use GIS technology to deliver both new services and social value. Azavea does work all over the United States, but it’s thrilling when we can make a contribution to a project in our hometown, Philadelphia, that is setting the standard for innovative ways to better manage our ecosystem,” says Robert Cheetham, Azavea President and CEO.

Representatives of Azavea and the PWD will be presenting at the next American Water Resources Association (AWRA) conference in Philadelphia from Nov.1 – Nov.4

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About Azavea

Azavea is an award-winning geospatial analysis (GIS) software development firm specializing in the creation of location-based web and mobile solutions, as well as geospatial analysis services to enhance decision-making. Azavea is committed to working on projects with a strong social value component in order to promote the emergence of more dynamic, vibrant, and sustainable communities. Each of Azavea’s projects, products and pro bono engagements showcases this commitment. Azavea is a certified B Corporation. For more information, visit

If you would like more information about Azavea or to schedule an interview with Robert Cheetham, Azavea’s CEO and President, please contact Abby Fretz at (215) 701 – 7503.

About the Philadelphia Water Department and Water Department Bureau

The Philadelphia Water Department and Water Revenue Bureau serve the Greater Philadelphia region by providing integrated water, wastewater, and stormwater services. The utility's primary mission is to plan for, operate, and maintain both the infrastructure and the organization necessary to purvey high quality drinking water, to provide an adequate and reliable water supply for all household, commercial, and community needs, and to sustain and enhance the region's watersheds and quality of life by managing wastewater and stormwater effectively. For more information, visit


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Abby Fretz
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