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Moulton Falls

Burnt Bridge Creek


Stormwater code and manual

Clark County has a National Pollution Discharge Elimination System (NPDES) permit effective August 1, 2013 through July 31, 2018. The Washington Department of Ecology permit is part of the federal Clean Water Act. Clark County has operated under such a permit since 1999.

Code and Manual update (2013-2015)

This permit, among other things, specifies regulations for managing the quantity and quality of stormwater discharged from the county’s stormwater system. To comply with the permit, the county will update applicable development codes, such as 40.385 Stormwater and Erosion Control and the stormwater manual.

Clark County will pursue updates that are:

  • Flexible and tailored to multiple project types, including making Low Impact Development (LID) the mandatory approach for stormwater management in site development.
  • Compatible with other state and local regulations to protect the environment and support an economically vibrant and liveable community.

For this project, refer to the follow sections for more information:

Update (July 2015)

NOTE: The DEAB meeting presentation has been moved to September 3rd.

The Washington State Department of Ecology has formally responded to Clark County's June 2014 submittal for the stormwater manual and code. Clark County will now work through final edits and revisions based on Ecology comments and stakeholder feedback. A new fact sheet is also available here with the project overview and frequently asked questions. Click here for the proposed schedule for the remainder of the project.

For more information on Ecology's permit and manual updates from December 2014, refer to the state's NPDES Phase I permit and stormwater manual web page.

Public Review Checklists prior to Adoption Draft

There are several documents that were available for public review and comment in the summer 2015.

Review Type
Document Name Downloadable file
Department of Commerce - code review (60-day review - closes August 17, 2015) Development related code - matrix of proposed changes .pdf file
State Environmental Policy Act (SEPA) (14-day review closes August 3, 2015) Notice - Determination of Nonsignificance .pdf file
  SEPA Checklist .pdf file
  Determination of Nonsignificance .pdf file


June 2014 Review Draft - Municipal Code and Stormwater Manual

For Department of Ecology review and comment (June 30, 2014)

Document Type
Document Name Downloadable file
Municipal Code 13.26A - Clean version .pdf file
  13.26A - strikeout / underline .pdf file
Municipal Code 40.386 - Clean version (replaces 40.385) .pdf file
  40.386 - strikeout / underline .pdf file
Document Type
Document Name
Downloadable file
Stormwater Manual Introduction to manual / TOC .pdf file (2.2 MB)
  Book 1 with appendices .pdf file (24.1 MB)
  Book 2 with appendices .pdf file (13.1 MB)
  Book 3 with appendices .pdf file (3.2 MB)
  Book 4 with appendices .pdf file (6.1 MB)


Review Draft - April - May 2014

Public comments were received on the Review Draft and incorporated in the Final Draft. Here is the County response to public comments received.

Tentative schedule for updates

  • April 11 - May 5, 2014: Public comment period for the Review Draft of code and manual language.
  • May 14, 2014: Work session with Board of County Commissioners to review draft language and public comments (check the Grid for audio recording).
  • June 30, 2014: Final Draft sent to the Washington State Department of Ecology (DOE) for 90-day review period.
  • June 2014 - June 2015: Revise code and manuals per Ecology comments. Continue public outreach, trainings and workshops with stakeholders and citizens.
  • June 2015 - December 2015: Host final stakeholder meetings and finalize documents. Board of County Councilors adoption of code and manual by December 2015.
  • August 19, 2015 - Board of County Councilors Worksession
  • October 1, 2015- Planning Commission Worksession
  • October 1, 20155 - Planning Commission Hearing
  • November 2015 - Board of County Councliors Public Hearing
  • January 8, 2016: All new Clark County stormwater code and manual regulations become effective.


The following documents will be referenced throughout the update process.

Document NPDES Permit Requirement
NPDES Permit from the Department of Ecology Clark County is a Phase 1 permittee.
Phase 1 permittee special conditions are required unless otherwise noted.
Clark County Stormwater Manual - November 2009 (PDF 1MB)
- Appendix A (PDF 1MB)
- Appendix B (PDF 7MB)
- Appendix C (PDF 1MB)
- Appendix D (PDF 14MB)
Minimum requirements 1, 2, 5, 6, 7 and 8
Clark County Pollution Control Manual; Best Management Practices
for Businesses and Government Agencies
- January 2009 (PDF)
Minimum requirement 3
Clark County Stormwater Facility Maintenance Manual - January 2009 (PDF) Minimum requirement 9
Stormwater Management Manual for Western WashingtonAugust 2012 Minimum requirements 2, 4, 5, 6, 7 and 8
Washington State Department of Transportation - 2014 Highway Runoff Manual Publicly funded road projects


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