Washington County, OR Landscaping Rules: Tree Removal & Heritage Trees (2026)

2 below, making a tree-removal application the default rule for unincorporated county land rather than the exception. 2 lists four carve-outs: trees already approved for removal in a Type II or III Development Plan; hazardous trees that endanger health or property, which fall under the Significant Habitat standards of Section 422 if located inside the Urban Growth Boundary (UGB); trees in a mapped floodplain or drainage hazard area inside the UGB, governed instead by Section 421; and trees within Significant Habitat inside the UGB, governed by Section 422.

3, a written narrative describing the size, species and condition of each tree, the purpose of removal, any floodplain or drainage hazard impacts, and a site plan showing every tree six inches or greater in diameter at four feet above grade, plus an approved erosion control plan from Clean Water Services. 4 requires trees proposed for removal to be flagged, staked or paint-spotted for field inspection, and if the harvest area sits within 25 feet of a side or rear property line, the applicant must also stake that line and identify the trees within the buffer.

B imposes the county's core substantive limit inside the UGB: commercial timber harvesting must use a selective cutting procedure, and clear-cutting is banned outright, defined as any harvest unit left with fewer than 50 living, healthy, upright trees per acre, each at least 11 inches in diameter at four feet above grade, distributed across the unit in roughly the same species mix that existed before the harvest.