Cedar Mill
Community Website

Search the Cedar Mill News:

About The
Cedar Mill News

Volume 15, Issue 9
September 2017


Cedar Mill Creek watershed flooding

The watershed in 1984, before rapid growth began.
The watershed in 1984, before rapid growth began.

An effort is underway to address flooding in the Cedar Mill/North Johnson Creek (CMNJ) watershed. Rapid development in the upstream areas, with the concurrent loss of trees and vegetation that slows stormwater, means that lower areas with shallower streambeds are experiencing increased flooding.

A meeting was held last May to update Butner Road area residents about flooding issues and hear their concerns. Prior to that meeting, more than 230 Cedar Hills/Commonwealth Lake neighbors contacted Washington County Land Use and Transportation (LUT) and Clean Water Services (CWS) urging the agencies to upgrade a culvert where North Johnson Creek, a Cedar Mill Creek tributary, passes under Butner Rd.

Rocky Brown, Washington County Floodplain Administrator, told the neighbors that simply increasing the size of the culvert could “pass the problem downstream.” A LUT project to replace the culvert this summer was delayed so that the situation could be studied more thoroughly.

The watershed

A project team, the Cedar Mill Creek Flood Remediation Collaborative, has been convened. The group consists of representatives from a number of agencies and other stakeholders, and is led by Washington County Board Chair Andy Duyck and Tualatin Hills Park & Recreation District Board President Jerry Jones. The study is being guided by “Oregon Solutions,” a statewide organization that brings “business, government, and nonprofits to the table to agree on what role each can play to address a community need.”

A June 19 letter from Oregon Governor Kate Brown authorizing the OS project says, “Oregon Solutions is in a unique position to manage a process that will include residents and business owners subjected to chronic flooding. This approach brings together partners in a neutral and collaborative way to develop solutions to reduce these long-standing flooding problems and identify opportunities for mutual benefits in terms of housing stability, economic development, and the environment in this flood-prone area of Washington County.”

A portion of a CWS map showing the area of the watershed prone to flooding. To view the whole map, view the News on the website and click on the link.
A portion of a CWS map showing the area of the watershed prone to flooding. To view the whole map in PDF format, click on the map.

The Collaborative had its first meeting on July 31. A presentation by Oregon Solutions consultant Bob Bailey noted that the challenge is “whether a group of agency, property owner, and resident stakeholders can use a ‘triple bottom-line approach’ to develop a realistic, phased approach and funding strategy…to minimize, mitigate, or eliminate flooding impacts while considering economic development, habitat value, and quality of life concerns.”

The presentation reported on stakeholder interviews and document reviews, and concluded:

  • CMNJ watershed has been significantly altered and watershed functions are seriously impaired;
  • Piecemeal decisions by multiple jurisdictions and agencies have contributed to problems;
  • Flooding problems are likely to get worse from additional development and climate change;
  • Attempts by individual jurisdictions and agencies to address flooding are not sufficient to address flooding problems;
  • A multi-stakeholder, watershed-scale approach is required to resolve and remediate flooding issues;
  • Fresh, non-traditional approaches will be required to address flooding;
  • Agreement that Oregon Solutions process would be crucial to identifying and implementing actions to resolve flooding.

The next meeting of the Collaborative will be held on October 10, 2-5 pm. The project website is linked from the projects page of Oregon Solutions' website. A variety of source documents are included for those interested in learning more. We'll share the location of the October meeting in the next issue and on the CMN Facebook page. If you would like to receive updates on the project, you can email Erik Jensen at or call 503-477-8312.

Previous article


Next article

Sign Up Now to receive
The Cedar Mill News by email each month

fb like
Like us on Facebook for timely updates

Cedar Mill News
Past Issues

Published monthly by Pioneer Marketing & Design
Publisher/Editor:Virginia Bruce
PO Box 91061
Portland, Oregon 97291
© 2017