The Philadelphia Water Department is leveraging GIS to create a billing system based on the amount of impervious surface cover on commercial properties. Stormwater billing based on impervious surface area both distributes the cost of managing stormwater more equitably and creates incentives for property owners to implement best management practices for mitigating stormwater runoff on-site.
The bill calculation is performed using a series of GIS models assembled using ArcObjects, python scripts and a geoprocessing queuing system. The resulting datasets are then made available to Water Department customers via an ArcGIS Server application. In addition to searching and mapping, the application supports the billing appeals process and enables users to calculate the estimated financial benefits of implementing stormwater mitigation activities. This presentation will showcase the Philadelphia Water Department application and outline the benefits and challenges of using GIS technology for stormwater management and impervious surface area calculations in urban environments.