Multnomah County, OR Fire Regulations: Brush Clearance (2026)
Key Facts
- Fuel break width
- 50 feet around buildings
- Steep-slope setback
- 50 ft from slopes over 30%
- Extra clearance
- up to 80 ft added on steep slopes
- Geographic reach
- Gorge Scenic Area forest zones only
- Exception path
- needs fire district recommendation
Summary
Buildings in Columbia River Gorge Scenic Area forest zones need a 50-foot defensible space fuel break clearing hazardous fuels around structures, plus wider clearance on steep slopes, but this applies only inside the Gorge boundary, not countywide or in Portland.
All buildings and structural projections such as porches, balconies and decks shall be surrounded by a maintained defensible space fuel break of at least 50 feet to minimize the risks associated with wildfire, unless the County approves an alternative pursuant to (B)(2) or (B)(3) below. Hazardous fuels shall be removed within the defensible space fuel break area. Irrigated or fire resistant vegetation may be planted within the defensible space fuel break. This could include green lawns and low shrubs (less than 24 inches in height). Trees should be spaced greater than 15 feet between the crowns and pruned to remove dead and low (less than 8 feet) branches. Accumulated leaves, needles, and other dead vegetation shall be removed from beneath trees.
(1) The defensible space fuel break shall be extended farther down the slope pursuant to the slope requirements below to minimize the risks associated with wildfire, unless the County approves an alternative pursuant to (B)(2) or (B)(3).
Percent Slope Less than 10 Less than 20 Less than 25 Less than 40
Distance In Feet No additional required 30 additional 55 additional 80 additional
Full Breakdown
Under MCC § 38.7305(B), every building and projection like a porch, balcony or deck in Columbia River Gorge National Scenic Area forest zones must be ringed by a maintained 50-foot defensible space fuel break with hazardous fuels removed; irrigated or fire-resistant plantings, spaced and pruned trees are allowed inside it. On slopes over 10 percent the break extends farther downhill: up to 80 additional feet on slopes near 40 percent. A narrower or wider alternative is allowed only with a local fire district or building official recommendation, or a County finding tied to protecting required riparian vegetation. This is Gorge-overlay law; it does not reach the rest of unincorporated Multnomah County or Portland, Gresham, Troutdale, Fairview or Wood Village, which have their own codes.
Violations & Fines
Noncompliance can block issuance or trigger revocation of the development or building permit; enforcement and fines for breaching Chapter 38 permit conditions run through the civil violation procedures in Multnomah County Code Chapter 39, Part 1.
Frequently Asked Questions
Does this rule apply to my house in Portland?
Can I get a smaller fuel break than 50 feet?
Sources & Official References
Other rules in Multnomah County
Compare Multnomah County to another location·View the Oregon fire regulations overview
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