How is my impervious area calculated?

The impervious area of a property is determined by using the following:

  • Aerial Photography
  • As-Built Drawings
  • Building Permits
  • Field Surveys
  • Final Approved Site Plans
  • Other Appropriate Engineering and Mapping Analysis Tools

Here is a commercial property fee example using aerial photography. The property is outlined below and the impervious area is shown in red hatching.


Impervious Area

Impervious Area Calculation

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1. How will my stormwater bill arrive?
2. My property is tax-exempt. Am I required to pay the stormwater utility fee?
3. What is an impervious area?
4. How is my impervious area calculated?
5. I think that the impervious area calculated for my property is incorrect? What should I do?
6. I own a commercial property and have made some improvements to my property that changed the impervious area (larger parking lot or building size). Will my stormwater utility fee change?
7. I believe that there may be an error to my fee. How do I make a request for an adjustment?
8. I live in a subdivision with stormwater BMPs and drainage infrastructure. Why do I have to pay the stormwater utility fee?
9. Who pays the stormwater utility fee?
10. What is the fee based on?
11. How much will I pay (fee rates)?
12. Can I petition for an adjustment of my stormwater fee?