Washington County, OR Environmental Rules: Erosion Control (2026)
Key Facts
- Permit required
- All grading, unincorporated county (§ 14.12.040)
- Small-excavation exemption
- Under 3 ft deep and 150 cu. yd.
- Engineer's report required
- Subdivisions, commercial, driveways over 150 ft
- Civil engineer stamp
- Needed at 2,000+ cu. yd. or 15%+ slope
- Plan review time
- 30 days, § 14.12.130
- Permit voids
- 180 days without starting work
Summary
Washington County requires a grading permit for excavation, fill, private road cuts and site grading anywhere in the unincorporated county, with detailed exemptions for small jobs, excavations under three feet or 150 cubic yards, minor fills, basements tied to an existing building permit, but not for larger or hazard-prone sites, which need a licensed engineer's geotechnical report.
14.12.010 - Scope. The purpose of this chapter is to regulate all civil engineering related work including site grading inside the un-incorporated areas of Washington County in order to safeguard health, safety, private property protection, public welfare, and to minimize erosion caused by said activities within. ... 14.12.040 - Permit—Required—Exemptions. No person shall do, cause, permit, aid, abet, suffer, or furnish equipment or labor for any grading without first obtaining a grading permit from the building official.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Community Development Code: Supplement 2 | Code of Ordinances: Supplement 25).
Full Breakdown
010). " The same section then carves out specific exemptions, excavations under three feet deep (or a cut slope under four feet and flatter than 2:1) that don't exceed 150 cubic yards; comparable small fills; basement and footing excavation already covered by a valid building permit; agricultural grading with a required drainage analysis; and driveways or private roads no longer than 150 feet that won't alter natural drainage. 110 requires a geotechnical engineering report for subdivisions, partitions, commercial projects, or any residential driveway over 150 feet, with an added engineering geologist report on slopes of 25 percent or steeper. 150).
Violations & Fines
Grading without the § 14.12.040 permit, or outside the scope of an exemption the county actually recognizes, exposes the responsible party to a stop-work order and permit denial, § 14.12.060 already bars issuance where the building official finds the work hazardous by reason of flood, geologic or seismic risk, or unstable soils. Section 14.12.170 lets the building official suspend or revoke a permit issued in error or obtained on incorrect information, and § 14.12.090 makes clear that having a permit never authorizes work that otherwise violates the chapter.
Frequently Asked Questions
Do I need a permit to grade or excavate my property in Washington County?
When does a project need an engineer-stamped grading plan?
How long does the county have to review a grading application?
What if I can't finish grading work within the permit's timeframe?
Sources & Official References
Other rules in Washington County
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