Grading & Drainage: Gresham vs Troutdale
How do grading & drainage rules compare between Gresham, OR and Troutdale, OR?
Gresham and Troutdale have similar restriction levels.
Gresham, OR
Multnomah County
Portland requires grading permits under PCC Title 24 for excavation or fill exceeding 50 cubic yards or slopes over 20%. Portland's Landslide Hazard areas (West Hills) require geotechnical reports. Drainage cannot be redirected onto neighboring properties (ORS 105.170). Retaining walls over 4 feet require engineered plans. Multnomah County Land Use requires grading permits in unincorporated areas on SEC overlay or steep slopes.
View full Gresham rules →Troutdale, OR
Multnomah County
Portland requires grading permits under PCC Title 24 for excavation or fill exceeding 50 cubic yards or slopes over 20%. Portland's Landslide Hazard areas (West Hills) require geotechnical reports. Drainage cannot be redirected onto neighboring properties (ORS 105.170). Retaining walls over 4 feet require engineered plans. Multnomah County Land Use requires grading permits in unincorporated areas on SEC overlay or steep slopes.
View full Troutdale rules →Key Facts Comparison
| Fact | Gresham | Troutdale |
|---|---|---|
| Portland Threshold | 50 cu yd / 20% slope | 50 cu yd / 20% slope |
| West Hills | Landslide overlay geo report | Landslide overlay geo report |
| Retaining Walls | Permit if >4 ft | Permit if >4 ft |
| State Law | ORS 105.170 drainage | ORS 105.170 drainage |
| DSL Permit | Wetlands/salmon habitat | Wetlands/salmon habitat |
Highlighted rows indicate differences between cities.
Gresham FAQ
Do I need a grading permit to regrade my yard?
Yes in Portland if you move over 50 cubic yards or work on slopes over 20%. Small gardening/landscaping is exempt. West Hills properties often require geotech reports for any earthwork.
Can I build a 3-foot retaining wall without a permit?
Under 4 feet typically exempt from structural permit under ORSC, but Portland still requires a zoning review if it affects setbacks or drainage. Always check with BDS.
Troutdale FAQ
Do I need a grading permit to regrade my yard?
Yes in Portland if you move over 50 cubic yards or work on slopes over 20%. Small gardening/landscaping is exempt. West Hills properties often require geotech reports for any earthwork.
Can I build a 3-foot retaining wall without a permit?
Under 4 feet typically exempt from structural permit under ORSC, but Portland still requires a zoning review if it affects setbacks or drainage. Always check with BDS.
Compare other topics
See how Gresham and Troutdale compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool