Accurate Stormwater Billing
Impervious surfaces - hard surfaces like concrete and asphalt - don't allow rain water to soak into the ground.
That can produce excessive stormwater runoff that fills and overflows city sewers.
Drainage in Indianapolis has always been a problem. Recently, the Stormwater Utility was established
to fund construction and maintenance of the City's new stormwater collection system. It was imperative that
the Utility begin collecting user fees as quickly as possible, so they turned to GIS for a solution.
GIS was used to calculate the area of impervious surfaces for over 40,000 non-residential parcels.
The project used GIS data - aerial photography, land ownership, and buildings - to visually inspect and
catalog all impervious surfaces in Marion County-Indianapolis. After compilation, GIS technology was used
to automatically calculate the amount of impervious surface, by type, for each parcel. The impervious
surface maps were posted online, and quality control was performed off-site. The completed data was provided
to a billing company who performed fee calculations and sent out the bills.
GIS continues to play a vital role as this project moves into the maintenance phase. Using GIS, construction
permits are located by address and impervious surfaces of new construction are captured from aerial photos.
Occasionally, field work is required, and GIS technology is used on Personal Digital Assistants (PDA).
Results
- GIS allowed the City to quickly set up a fair and equitable revenue source that will generate
$7Million - $8Million per year for improving stormwater drainage.
- The project was on a highly accelerated five-month schedule. By using GIS, it was completed on time and
within budget.
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