Stormwater Management

What is Storm Water?

Stormwater runoff is generated from rain and snowmelt events that flow over land or impervious surfaces, such as paved streets, parking lots, and building rooftops, and does not soak into the ground. The runoff picks up pollutants like trash, chemicals, oils, and dirt/sediment that can harm our rivers, streams, lakes, and coastal waters. To protect these resources, communities, construction companies, industries, and others, use stormwater controls, known as best management practices (BMPs). These BMPs filter out pollutants and/or prevent pollution by controlling it at its source.

Illicit Discharge Requirements & Conditions

Illicit discharges are:

  • Hazardous waste
  • Liquid or solid wastes
  • Operational wash water
  • Septic or sewer connections

Reporting Discharges
To report a suspected illicit discharge in Selah, Sunnyside, Union Gap, or the County, call 509-574-2300 or email.

Under certain conditions, the following are not illicit discharges:

  • Dust control water
  • Lawn water
  • Permitted discharges covered under another permit
  • Street/sidewalk wash water
  • Swimming pool discharge – dechlorinated pool water only at undetectable levels (0.1mg/L).
  • Water line or hydrant flush water

Illicit discharges are not:

  • Air conditioning condensate
  • Uncontaminated crawl space pump discharge
  • Footing drains
  • Foundation drains
  • Ground water
  • Irrigation water from agricultural sources

Annual Storm Water Report

2015-2017 Biennial Stormwater Capacity Grants

2019 Stormwater Management Manual for Eastern Washington

2019 Regional Stormwater Management Program

City of Selah Storm Sewer System Map