Stormwater Fees

Stormwater fees are measured in ERUs, which stands for Equivalent Rate Unit. The amount of ERUs used for billing is calculated by the number of square feet of impervious surface on a property. This number is then divided by 1,500 square feet, which was determined to be the most equitable basis of distribution.

The current stormwater rate per ERU, as well as scheduled increases through 2028, is as follows:

Effective DateRate per ERU
April 1, 2023$4.19
January 1, 2024$4.69
January 1, 2025$5.25
January 1, 2026$5.88
January 1, 2027$6.59
January 1, 2028$7.38

Learn more about the stormwater rate structure or visit our stormwater FAQs page for additional information.

Stormwater Credit Manual

The City of Flagstaff has revised the Stormwater Credit Manual (PDF). The manual is a document which provides for discounts on your stormwater billing (as shown on your water bill) for certain stormwater controls such as detention basins, Low Impact Development (LID) facilities, and rainwater harvesting. Many developments that have occurred since 1990 may be eligible for a discount. The discount may be applied to commercial, industrial or residential developments. 

If you believe you or the subdivision you live in may have a stormwater facility that is eligible, you are encouraged to apply for a discount (PDF). You will need to attest that the facility(s) are maintained on a regular basis by yourself or perhaps by a Homeowner's Association as part of the application process. 

To find out if your property may be eligible for a discount, contact Ed Schenk at 928-213-2470. Please submit the completed application to or mail to:

City of Flagstaff Stormwater Manager: Ed Schenk
2323 N Walgreens Street, Suite 1
Flagstaff, AZ 86004