The City of Portland adopted 2020 editions of the Stormwater Management Manual (SWMM) and Source Control Manual (SCM). The new editions of the manuals are in effect starting Dec. 14, 2020.
Find more information and a summary of changes for each manual at:
Both manuals will have a 3-month phase-in period where either the 2020 or 2016 edition may be used for projects. Version applicability as it relates to different project and permit review types is described in more detail on the respective websites.