Stormwater Code

What It Is

Our stormwater regulations protect people, property and the environment from damage caused by stormwater runoff. Our stormwater codes also satisfy the City's obligation to comply with our Municipal Stormwater Discharge National Pollutant Discharge Elimination System (NPDES) Permit, issued by the Washington State Department of Ecology.

What the Stormwater Code Addresses

• Drainage control submittal and review requirements
• Erosion control requirements for your project during construction and grading activities
• Flow control and stormwater treatment requirements
• How we enforce the Stormwater Code
• On-Site Stormwater Management and why it's important
• Where the stormwater from your site needs to go

How to Tell if You Need Drainage Review

You need to get a drainage review for your construction or grading permit if:

• A Grading Permit is required for your project  
• You are adding or replacing more than (blank) square feet of a building (as measured by the roof outline)
• You are adding or replacing more than (blank) square feet of hard surfaces, such as pavement
• You are disturbing more than (blank) square feet of land

Read the Code

For more information on existing stormwater regulations, read AMC Chapter 14.14.

Proposed Changes

None.

Additional Information

• Note: If your project has (blank) square feet, or greater, of new plus replaced hard surface area, your application must be prepared by a professional engineer.
• Note: A Department of Ecology Construction Stormwater General Permit is required for projects disturbing one or more acres of land.