Environmental Rules in Portland, OR (2026)
5 verified environmental rules for Portland, Oregon, sourced directly from the municipal code and official government pages.
Verified from official government sources
Stormwater Management
Portland requires development and redevelopment projects that create or replace impervious surface to manage stormwater onsite, treating pollutants and controlling flow rate under standards set in the city's Stormwater Management Manual.
Portland Stormwater Management Rules
Some RestrictionsPortland City Code § 17.38.035
Stormwater must be managed in as close proximity to the development or redevelopment site as is practicable. This section is intended to prevent a net negative impact on nearby streams, wetlands, groundwater, and other water bodies. All local, state, and federal permit requirements related to implementation of stormwater management facilities must be met by the owner/operator prior to facility...
Erosion Control
Portland requires a permit for most grading and earthwork, with drainage and terracing standards for every cut or fill slope on private property.
Portland Grading & Drainage Permit Rules
Some RestrictionsPortland City Code § 24.70.020(B)
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 gr...
Flood Zones
Portland requires a development permit before any construction, fill, or grading in a mapped flood hazard area, with elevation and floodproofing standards set by zone.
Portland Flood Hazard Area Rules
Some RestrictionsPortland City Code § 24.50.060(A)
A. Permits. All permit applications will be reviewed to determine whether proposed development and building sites comply with the provisions of this Chapter and will be reasonably safe from flooding. A development or building permit must be obtained before construction or development begins within any flood hazard area. The development or building permit is required for all structures, inc...
Boat Dock Permits
New residential floating docks on Portland's Willamette River frontage are capped at 200 square feet with no variances, and shallow water habitat is off-limits to docks entirely.
Portland Boat Dock Size Limits
Significant RestrictionsPortland City Code § 33.475.225(B)
B. Residential dock standards. The following standards apply to new floating boat docking structures located in a residential zone. 1. The total square footage of the new floating boat docking structure must not exceed 200 square feet. Adjustments are prohibited; and 2. The new floating boat docking structure may not be located within shallow water habitat. Adjustments are prohibited. Modificat...
Flood Elevation Requirements
Portland requires new construction in flood hazard areas to elevate the lowest floor above the base flood elevation plus a freeboard buffer that runs 1 to 2 feet depending on the waterway.
Portland Flood Elevation & Freeboard Rules
Some RestrictionsPortland City Code § 24.50.050(D)
Willamette River FIRM Flood Zone AE. These flood zones represent areas for which the base flood elevations are determined. The flood protection elevation is the base flood elevation plus 2 feet of freeboard. E. Johnson Creek, Fanno Creek and Crystal Springs Creek FIRM Flood Zone AE. This flood zone represents areas for which the base flood elevations are determined. The flood protection e...
Looking for Multnomah County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Portland city rules.
Environmental Rules in Multnomah County →