Multnomah County, OR Invasive Plant Rules: Prohibited Species (2026)
Key Facts
- Overlay
- SEC-h (Significant Wildlife Habitat)
- Operative section
- MCC 39.5540(C)(1)(e)
- Species list source
- MCC 39.5520 definitions
- Coverage
- Unincorporated county only, not Portland
- Enforcement
- Daily civil fines, MCC 39.1510
Summary
Unincorporated Multnomah County's SEC-h wildlife-habitat overlay bans planting nuisance and invasive nonnative plants and requires their removal from cleared areas as a development-permit condition. Portland and its own municipal code are not covered by this rule.
(e) Nuisance and invasive nonnative plants, as defined in MCC 39.5540 shall not be planted on the subject property and shall be removed and kept removed from cleared areas of the subject property.
(f) Ground disturbing activity within 100 feet of a water body as defined by MC 39.2000 shall be limited to the period between May 1st and September 15th. Revegetation and soil stabilization must be accomplished no later than October 15th.
(g) Outdoor lighting shall be of a hooded fixture type and shall be placed in a location so that it does not shine directly into undeveloped habitat areas. Where illumination of habitat area is unavoidable, it shall be minimized through use of limited lumens with a hooded fixture type and proper placement. The location and illumination area of lighting needed for security of public utility facilities shall not be limited by this provision but should be done in a minimalistic manner.
(D) Mitigation Plan Criteria
(1) Mitigation Plan Requirements. An applicant shall propose a mitigation plan that provides mitigation activities and plantings as outlined in subsection (2) or (3) below. The mitigation area shall first be located within any existing non-forested cleared areas contiguous to forested areas, second within any degraded stream riparian areas and last in forested areas or adjacent to landscaped yards.
Full Breakdown
The Zoning Code defines nuisance and invasive nonnative plants as anything on the current Metro Nuisance Plant List, the Prohibited Plant List, or the Oregon Noxious Weed List (MCC 39.5520). Where a property sits in the Significant Wildlife Habitat (SEC-h) overlay, a development permit application must show these species are not planted and are removed and kept removed from cleared areas of the site under MCC 39.5540(C)(1)(e). A parallel removal duty applies to riparian (SEC-wr/SEC-s) mitigation plans under MCC 39.5590. Portland lots, which sit outside county jurisdiction, follow the city's own code instead.
Violations & Fines
Zoning violations are enforced under MCC 39.1510-39.1690: the County can issue a Notice of Violation, require remediation and vegetation removal, and assess civil fines for each day the violation continues.
Frequently Asked Questions
Does this apply inside Portland?
What counts as a prohibited invasive plant?
When must these plants be removed?
Sources & Official References
Other rules in Multnomah County
Compare Multnomah County to another location·View the Oregon invasive plant rules overview
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