Show All Answers

1. Why is impervious surface area used to determine a property's stormwater user fee?

The City designed the user fee to be related to the demand a property places on the City’s stormwater services. That demand is determined primarily by the amount, peak flow rate, and quality of stormwater runoff flowing from a property, which in turn is directly related to amount of impervious surface area located on the property. Most municipalities around the country implementing a stormwater user fee base the fee on a property’s impervious surface area.

2. What is considered an impervious surface?

An impervious surface is one that, because of the surface’s composition or compacted nature, impedes or prevents natural infiltration of water into the soil. This includes roofs, solid decks, driveways, patios, sidewalks (other than public walks located in the City’s right-of-way), parking areas, tennis courts, concrete, asphalt, or crusher/run streets or paths, and compacted gravel or dirt surfaces, as determined by the Department of Public Works.

3. What is not considered an impervious surface?

Those areas that allow water to infiltrate naturally into the ground, such as forests, gardens, and areas covered with grass, are not counted as impervious surface areas.

4. How is the amount of impervious surface area on my property calculated?

The amount of impervious surface area on your property is determined using a combination of data. First, the City uses geographic information system (GIS) data and aerial photos of the City that are updated approximately every five years to distinguish impervious surfaces (such as roofs and parking lots) and pervious surfaces (such as lawns and gardens). Then the square footage of impervious areas is calculated and an ERU value assigned. Information concerning the amount of impervious surface area added or removed in connection with building permits is used to update impervious surface calculations in between aerial photo updates. You can see the impervious area of your property using the City’s web map.

5. What if I disagree with the amount of impervious area listed on my bill?

You can file an application with the Superintendent of Public Works to contest the calculation of the impervious surface area on your lot. The application is available online in both Excel and PDF formats or in the office of the Superintendent of Public Works in City Hall, and you only need to fill out Part I of the application. There is an application fee of $50 to pay for a portion of the staff time and processing costs involved in reviewing the request. If your application is denied, you can appeal to the Board of Public Works. Information on the appeal process is included with the denial letter. If your application is accepted, then the City will update the information in the system. Please Note:
1. Updated data for one-, two-, and three-family residences will not reduce the stormwater fee for those properties (unless it reflects that the entire lot has less than ¼ ERU of impervious surface area), because those properties pay a flat fee based on the average amount of impervious surface area on those properties.
2. For other properties, updated data will only impact user fee if it changes the total impervious surface area on the lot, when rounded up to the nearest ¼ ERU