Benton County, OR Invasive Plant Rules: Prohibited Species (2026)

320, part of the Riparian and Wetland Areas standards in Chapter 88, the Natural Features Overlay applying within the Corvallis Urban Fringe, opens with a broad prohibition: removal or alteration of vegetation from Riparian Areas, and from Systems-Critical Wetlands and associated 25-foot buffers, is prohibited except for the following purposes. Twelve numbered exceptions follow, and subsection (1)(d) carves out invasive species specifically: removal is allowed for non-native, invasive, and/or noxious vegetation, as identified in the Oregon Department of Agriculture's Oregon Weed Policy and Classification System (Appendix 1), including weeds designated as A, B, and/or T.

That exception is conditioned, not unlimited: as necessary to control erosion, areas of vegetation removal shall be re-vegetated with native species listed on the City of Corvallis Native Plant List, and where erosion risk requires it before new plantings establish, the property owner must use short-term, non-structural erosion control measures. 320(1)(e) allows substituting native plants for non-native ones even without removal, provided the replacement species match the ecological-function category of what they replace. 700(3)(a)(D) for the High-Protection Floodplain in the Corvallis Urban Fringe, so the county applies one consistent standard for identifying and clearing invasive plants across its riparian, steep-slope, and floodplain natural-features overlays.