NPDES Stormwater Permit

Spill Hotline_2021

Contact Us:

Public Works Director email 

Public Works Office

14525 Main St. NE
P.O. Box 1300
Duvall, WA 98019
Directions (PDF)

Ph: 425.788.3434
Fx: 425.788.0311

After Hours Public Works Emergency
Ph: 425.419.3748 (Please note this number does not receive text messages)

Staff Directory


  1. NPDES Stormwater Permit
  2. Stormwater Management Plan
  3. Public Education
  4. Stewardship
  5. Stencil a Storm Drain
  6. Adopt a Drain
  7. Illicit Discharges and Spills
  8. Private Storm Drainage Maintenance
  9. Low Impact Development (LID)

National Pollutant Discharge Elimination System (NPDES)

The NPDES permit requires the City to take numerous actions to reduce the amount of polluted surface and stormwater runoff flowing into our creeks, streams, rivers, and groundwater. This Permit is issued to the City by the Washington State Department of Ecology and satisfies a mandate within the Federal Water Pollution Control Act of 1948. Due to growing public awareness and concern it was amended in 1972 and is now commonly known as the Clean Water Act (CWA). 

This permit requires the city to:

  • Provide Outreach and Education: work with people and businesses to promote daily activities that reduce stormwater pollution.
  • Inform and involve the public: give people the opportunity to weigh-in on how we meet permit requirements.
  • Respond to spills and seek out cross-connection pipes: this activity is called an "illicit discharge detection and elimination program (Spill Response).
  • Review development projects: ensure stormwater facilities are built to City standards, and that construction activities don't pollute stormwater.
  • Inspect and maintain public facilities: inspect and clean infrastructure, and make repairs if necessary.
  • Inspect and ensure private facilities are maintained: inspect private facilities and ensure property owners maintain and make repairs if necessary.

NPDES Municipal Stormwater Permit

2023 Annual Report DRAFT

Learn More! Water Cycle Glossary of Terms

The City of Duvall welcomes comments and feedback on our current Stormwater Management Program. After reviewing the documents and information please provide your feedback by clicking on the feedback button below.  Be as detailed as possible, we value your input!

SWMP Annual Reports

Most Recent Report

All Reports

2023 Submittal Certification
2022 Submittal Certification
2021 Submittal Certification
2020 Submittal Certification
2018 Submittal Certification
2017 Submittal Certification
2016 Submittal Certification
2015 Submittal Certification


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