Stormwater, also spelled storm water, is water that originates during precipitation events and snow/ice melt. Stormwater can soak into the soil (infiltrate), be held on the surface and evaporate, or run off and end up in nearby streams, rivers, or other water bodies (surface water).

Stormwater Runoff Diagram

Drainage System

A stormwater drainage system can be as simple as a ditch that outlets to a stream or as complex as a system comprising numerous intakes, manholes, and pipes along with ditches, stormwater retention or detention basins, and pump stations.

For the City of Sultan - we have approximately 82,000 linear feet (15.5 miles) of stormwater system pipes and major culverts. Approximately 820 catch basins and 160 inlets are located throughout the service area (from City of Sultan Comprehensive Plan updated September 25, 2008). Grass-lined ditches are also part of the stormwater collection system.

In addition to the conveyance assets, the city owns and maintains infiltration facilities and retention ponds. Approximately 13 such facilities are owned and operated by the city. There are numerous privately-owned stormwater facilities scattered throughout the City of Sultan service area including approximately 44 privately-owned ponds in the Sultan Urban Growth Area (UGA).

Stormwater Utility

A stormwater utility is essentially a special assessment district set up to generate funding specifically for surface water management (City Ordinance 14.04). Users within the district pay a surface water fee, and the revenue generated directly supports:

  • Maintenance and upgrades of existing storm drain systems
  • Development of drainage plans, flood control measures, and water-quality programs
  • Administrative costs
  • Sometimes construction of major capital improvements

Unlike a stormwater program that draws on the general tax fund or uses property taxes for revenue, the people who benefit are the only ones who pay.

Surface Water Management

Surface water management within the City is governed by federal, state, regional, county, and city laws, including the:

  • Clean Water Act
  • Endangered Species Act
  • Growth Management Act
  • Puget Sound Water Quality Action Plan
  • Shoreline Management Act
  • State Environmental Policy Act
  • Stormwater Management Performance Standards

Other Services Provided

Services provided include on-going maintenance of City owned facilities and "vactoring" manholes and catch basins to remove sediment and increase system capacity. The utility also provides funds to repair and/or replace failing culverts to reduce flooding.