West Linn adopts its own stormwater management manual to align with DEQ permit

The West Linn City Council voted May 12, 2025, to adopt the City of West Linn Stormwater Management Manual by approving Resolution 2025-01.

Assistant City Engineer Clark Wright told the council the manual replaces the City of Portland manual the city had been using and better aligns post-construction standards with the city's soils, topography and DEQ permit requirements. Wright said the draft was posted for 30 days starting March 17 and the city received no public comments.

Wright said the new manual is tailored to local conditions and will be easier for the city to update over time as new best-management practices emerge. "We needed to come together on that, and...the best way to do it was to develop our own manual," Wright said, citing discrepancies the city found between DEQ permit requirements and enforcement under the Portland manual.

Councilors thanked staff and the city attorney for their work. Councilor Bridal said she appreciated the city-specific approach and the ability to update the manual as needed. Council President Baumgartner noted the manual is available online and said he had read the first page prior to the meeting.

The resolution passed by roll call with councilors voting in the affirmative. The adopted manual is a 27-page document posted on the city website; staff said it contains primarily minor grammatical edits from the public draft and no substantive changes. Adoption makes the West Linn manual the city's formal post-construction stormwater standard as required by the DEQ permit.

Staff said the change gives the city clearer local standards to apply when reviewing site plans and constructing stormwater controls and allows the city to amend its manual independently of Portland's updates. The manual's adoption is an administrative action implemented by the Public Works and Development Services departments.