FEMA flood zone rules in Multnomah County, OR — also called floodplain regulations or special flood hazard area (SFHA) rules — determine flood insurance requirements and elevation standards for new construction.
Multnomah County has extensive flood management responsibilities along the Columbia and Sandy Rivers. The Urban Flood Safety and Water Quality District (est. July 1, 2024) manages 13,000 acres of floodplain including 27 miles of levees. County flood hazard areas require permits and NFIP compliance. Community Rating System discounts flood insurance premiums.
Multnomah County's floodplain management is extensive: the county borders both the Columbia River and Sandy River with major flood hazard areas. The Urban Flood Safety and Water Quality District (UFSWQD), established July 1, 2024, replaced four historic drainage districts and manages 13,000 acres of Columbia River floodplain with 27 miles of levees protecting Portland, Gresham, Fairview, Troutdale, and unincorporated areas. Multnomah County participates in FEMA's NFIP. Development in any FEMA Special Flood Hazard Area requires a flood hazard/development permit and must meet elevation and floodproofing standards. Floodway development is prohibited without a no-rise certification. The county participates in the Community Rating System, providing flood insurance discounts. The levee system is over 100 years old and does not currently meet all federal standards — upgrade efforts are underway through Measure 26-243 bond funds. Check portlandmaps.com or contact Multnomah County Land Use Planning: 503-988-3043.
Development in floodplain without permits: stop-work orders, mandatory remediation, NFIP compliance consequences.
Multnomah County, OR
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Multnomah County, OR
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Multnomah County, OR
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Multnomah County, OR
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Multnomah County, OR
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Multnomah County, OR
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See how Multnomah County's flood zones rules stack up against other locations.
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