Stormwater Division

The City of Milton’s Surface Water Division is comprised of three full-time employees, one of which is the supervisor of the division. Additionally, the City employs one Stormwater Compliance Inspector. This position is a result of the Department of Ecology’s National Pollutant Discharge Elimination System (NPDES) Western Washington Phase 2 Municipal Stormwater Permit requirements.

Surface Water Drainage

The City of Milton created the Surface Water Drainage Utility to provide the services necessary to address surface water issues. The foremost being water quality and flood prevention. This division responds to citizen requests, plans for capital improvements, manages projects, and inspects construction sites within the City. Fees are assessed to properties based on their respective contribution to surface water drainage. This is calculated as the amount of impervious surface area for a given parcel. View the Department of Ecology 2014 Storm Water Management Manual.

Surface Water Rates

Commercial drainage rates are based on Equivalent Service Units (ESU): 1 ESU equals 2,800 square feet of impervious surface. Each ESU equals $15.50.

Residential drainage rates are based on a tiered system. The percentage of impervious area as a function of the total property area determines which tier the property will be billed under. Rates are as follows:

TierPercent ImperviousRate per Month
10 to 40$15.50
241 to 70$25.50
371 plus$35.50


Undeveloped properties are assessed a charge of $5.10 per month and billed annually.

Volunteer Opportunities

Would you like to get involved? Find out more about local volunteer opportunities with these organizations: