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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 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.

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

Final Adoption of Clark County Stormwater Manual and Code

The Final Adoption versions of the code and manual will be discussed at the November 24, 2015 Board of County Councilor's public hearing. Citizens may testify during the public hearing at 10:00 am (refer to the meeting agenda for more information). Materials will be posted in the table below by November 10th.

Document type Document description Downloadable .pdf
Staff report To BOCC includes Planning Commission recommendation
Adopting Ordinance Includes all code changes, including updates to 13.26A, new 40.386, and edits to various Title 40 code sections
Stormwater Manual Introduction chapter
Stormwater Manual Book 1 - Administration
Stormwater Manual Book 2 - BMP Design
Stormwater Manual Book 3 - Source Control
Stormwater Manual Book 4 - Operations / Maintenance


Adoption Draft of Clark County Stormwater Manual and Code

The Adoption Draft versions of the code and manual will be discussed at upcoming Planning Commission meetings in October 2015. Based on comments received, a final version will be prepared for the Board of County Councilors public hearing in November 2015. Send any comments on the following Adoption Draft documents to

Document Type Document Name Downloadable .pdf
Summary document Proposed code change summary matrix
Municipal Code 13.26 A (strike out / underline)
Municipal Code 40.386 (to replace 40.385)
Stormwater Manual Introduction chapter
Stormwater Manual Book 1 - Administration
.pdf (30.3 MB)
Stormwater Manual Book 2 - BMP Design
.pdf (25.5 MB)
Stormwater Manual Book 3 - Source Control
.pdf (4.1 MB)
Stormwater Manual Book 4 - Operations / Maintenance
.pdf (9.4 MB)


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


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
  • September 3, 2015 - Development Engineering Advisory Board
  • October 1, 2015- Planning Commission Worksession
  • October 15, 2015 - Planning Commission Public Hearing
  • November 24, 2015 - Board of County Councilors Public Hearing (10:00 am)
  • 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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