Street, Stormwater, and Development Standards

The adopted current version of the City of Mill Creek Street and Development Standards are found here: 2022 Mill Creek Standard Plans.

The 2022 version supersedes all previous versions as of January 20, 2022.

Please note that, as of July 26, 2022, all references in the City of Mill Creek Street and Development Standards to the use of the "2014 revision to the 2012 Stormwater Management Manual for Western Washington" have changed to the "2019 Stormwater Management Manual for Western Washington". This change will be corrected in the 2023 update to the City of Mill Creek Street and Development Standards, but is formally now in effect.

City of Mill Creek Street and Development Standard Details references the most recent edition of the "WSDOT Standard Specifications", which is the Standard Specifications for Road, Bridge, and Municipal Construction published by the Washington State Department of Transportation (WSDOT).  To access this document online and for more information, go to Standard Specifications by Washington State Department of Transportation.

The city coordinates with the Washington State Department of Transportation (WSDOT) and Snohomish County for traffic mitigation requirements and development impacts to Bothell-Everett Highway (State Route 527) and 132nd Street NE (State Route 96). Additional requirements may apply to developments along these streets in Mill Creek which will further amend the City Standard Details.

What is a Stormwater Site Plan?
Stormwater Site Plans (parts of which are often called drainage plans, drainage reports, temporary erosion and sediment control/TESC plans, etc.) are a compilation of project drawings, standard or project-specific details, reports, and design analysis that together demonstrates how surface water and stormwater will be managed at a project location; both temporarily during construction or landscaping work, and permanently after the work is completed. The requirements for each Stormwater Site Plan will vary greatly depending on the size and scale of the project, the proximity of the work to both existing surface and underground stormwater management features and natural or artificial water bodies.

The City of Mill Creek has implemented the 2019 Department of Ecology Stormwater Management Manual for Western Washington as the basis for City public and private surface water and stormwater design and management. Stormwater Site Plans are prepared in accordance with the guidance and requirements of the 2019 Department of Ecology Stormwater Management Manual for Western Washington. In particular, Volume I of the 2019 Department of Ecology Stormwater Management Manual for Western Washington will guide you in determining what requirements apply to your project or activity, and so what you need to submit to the City for review and approval.

To access this document online and for more information, go to Washington State Department of Ecology.

Construction Stormwater General Permit
In addition to permitting by the City of Mill Creek, many construction sites, including both new development and redevelopment, may need to be approved by the Washington State Department of Ecology for coverage under the Construction Stormwater General Permit. This coverage, and the requirements and costs of coverage by this construction permit (including inspections and reporting during construction), are all additional to permit and approval requirements required by the City of Mill Creek for surface water and stormwater-related design and management.

For information on how to obtain coverage under the Washington State Department of Ecology Stormwater General Permit, please go to:  Ecology Construction Stormwater General Permit .

Industrial Stormwater General Permit
Industrial facilities that discharge stormwater need to obtain coverage under the Washington State Department of Ecology Industrial Stormwater General Permit.

For information on how to obtain coverage under the Washington State Department of Ecology Industrial Stormwater General Permit, please go to:  Ecology Industrial Stormwater General Permit