​​​​​​​​​​​​​2027 Stormwater Design Manual and Associated Kitsap County Code Update​

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In 2024, Ecology revised its stormwater design manual for Western Washington communities. As such, Kitsap County is mandated to update it’s Stormwater Design Manual and relevant design standards for consistency. In parallel, the project will modernize, clarify, and align KCC (Title 12 and related provisions) and the KCSDM to improve predictability, usability, and enforceability for applicants, reviewers, inspectors, and the public. 

This project will also lead to improved internal consistency throughout the review, construction, and post-approval phases of Site Development Activity Permits (SDAPs).​ Kitsap County Departments of Community Development and Public Works have embarked on a review and update process, with the assistance of a consulting firm.

Scope of Work

In June 2026, Consultants (RKI and Hazen) were contracted by Kitsap County to update the Kitsap County Stormwater Design Manual (SDM), conduct focused review of the Kitsap County Code (KCC), and assist with revisions to the KCC.

Background​

As part of the United States Clean Water Act and National Pollutant Discharge Elimination System (NPDES) permit program, Kitsap County is required to develop and implement a stormwater management program.  This program is intended to reduce discharge of pollutants to the maximum extent practicable and protect water quality. The Washington State Department of Ecology is the responsible agency for permit issuance to local jurisdictions.

Kitsap County is considered a Phase II NPDES permit jurisdiction and is located within census-defined urbanized areas and includes Urban Growth Areas defined by the Washington State Growth Management Act. As a Phase II jurisdiction, stormwater runoff and associated codes must comply with Ecology's rules to prevent and control the impacts of stormwater runoff from new development, redevelopment and construction activities.​

 Previous 2021 Stormwater Design Manual Update