Portland, OR Environmental Rules: Erosion Control (2026)
Key Facts
- Governing chapter
- PCC Chapter 24.70
- Permit exemption
- fill under 10 cubic yards
- Terrace spacing
- every 30 vertical feet
- Retaining wall permit trigger
- over 4 feet tall
- Building pad gradient
- 2% toward drainage
Summary
Portland requires a permit for most grading and earthwork, with drainage and terracing standards for every cut or fill slope on private property.
B. Grading permits. A permit is required and will be issued in accordance with Section 24.10.070 for all grading operations with the exception of the following:
1. Grading in an area where, in the opinion of the City Administrator, there is no apparent danger, adverse drainage, or erosion effect on private/public property, or inspection is not necessary;
2. An excavation below finished grade for basements and footings of a building, retaining wall, or other structure authorized by a valid building permit. This does not exempt any fill made with the material from such excavation nor exempt any excavation having an unsupported height greater than 5 feet after the completion of such structure.
3. Cemetery graves.
4. Refuse disposal sites controlled by other regulations.
5. Excavations for wells or tunnels.
6. Mining, quarrying, excavating, processing, stockpiling of rock, sand, gravel, aggregate, or clay where established and provided for by law provided such operations do not affect the lateral support or increase the stresses in or pressure upon any adjacent or contiguous property.
7. Exploratory excavations under the direction of soil (geotechnical) engineers or engineering geologists.
8. An excavation that
a. Is less than 2 feet in depth, or
b. Does not create a cut slope greater than 5 feet in height and steeper than 1‑1/2 horizontal to 1 vertical.
Full Breakdown
Portland City Code Chapter 24.70 requires a permit for clearing, grading, and retaining wall work on private property, issued under Section 24.10.070. Grading is exempt only for narrow cases: minor excavations under 2 feet deep, fills under 1 foot deep and under 10 cubic yards, basement/footing excavation tied to a valid building permit, and a few other listed exceptions. Approved grading must include drainage and terracing under Section 24.70.100, terraces at least 6 feet wide every 30 vertical feet, subsurface drainage where needed for stability, and building pads graded at a 2 percent drainage gradient toward approved facilities unless the City Administrator waives it. Retaining walls over 4 feet tall need a permit too.
Violations & Fines
Grading or building a retaining wall over 4 feet without the required permit is a code violation the City Administrator can order stopped and corrected; the Administrator can also require bonds to guarantee hazard mitigation and can order remediation of any grading found to endanger property or adversely affect drainage.
Frequently Asked Questions
Do I need a permit to grade my Portland yard?
What drainage standards apply to graded slopes?
Sources & Official References
Other rules in Portland
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Erosion Control in Nearby Cities
How other cities in Multnomah County handle erosion control.