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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Suite 1000, Portland, OR 97204

Floodplain Construction Requirements

High water in Johnson CreekAlways call the City of Portland at 503-823-6892 before you build on, alter, regrade or fill on your property, or if you see building or filling without a City permit sign posted. A permit is required to ensure that projects do not cause problems on other properties and meet city, state and federal requirements.

New buildings in the floodplain must be protected from flood damage. Portland’s building code requires that new residential buildings must be elevated at least two feet above the base, or 100-year, flood except in the Columbia River floodplain where the requirement is one foot above base flood elevation. No new construction or filling is allowed in the floodway, unless it can be demonstrated through hydrologic analysis that it will not increase in the base flood elevation.

Review Portland City Code regulating construction in floodplains.

Heartbleed Security Notice

A serious security vulnerability known as "Heartbleed" was recently discovered in OpenSSL, a popular software library commonly used by many websites on the internet to encrypt communication between a user's computer and a web server.

PortlandOregon.gov is NOT affected by this vulnerability as it does not use the OpenSSL software library. Please rest assured we are dedicated to protecting your security on this website.