Marion County Floodplain Program
Along with the Willamette River, Marion County has many streams and rivers that are subject to flooding. Under certain conditions, such as the storm events that occurred from December 1996 through February 1997, rain and melting snow cause these streams and rivers to overflow their banks. As you can see from these pictures, homes and property suffered significant damage:
Recent Changes to the County Floodplain Overlay ZonesTo conform with recent changes in federal law, the Marion County Board of Commissioners amended the Marion County Code floodplain overlay zones. The definitions of substantial damage and substantial improvement were changed, exemptions to regulations (particularly those pertaining to certain types of fences and small structures) were included, and the urban code was amended regarding structures exempt from elevation certificate requirements.
Substantial Improvement/Substantial DamageThe county’s definitions of “substantial improvement” and “substantial damage” determine when a property that is being remodeled or rebuilt after being damaged is required to be brought up to current floodplain standards. When the threshold of substantial improvement or substantial damage is met, the existing structure must be brought up to current flood resistant standards. Generally, this could include elevating the first floor, installing openings in the foundation, and using flood resistant materials.
“Substantial improvement” means any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the “start of construction” of the improvement. This term includes structures which have incurred “substantial damage,” regardless of the actual repair work performed. The term does not, however, include either:
(1) Any project for improvement of a structure to correct existing violations of state or local health, sanitary, or safety code specifications which have been identified by the local code enforcement official and which are the minimum necessary to assure safe living conditions or
(2) Any alteration of a “historic structure,” provided that the alteration will not preclude the structure’s continued designation as a “historic structure.”
“Substantial damage” means damage of any origin sustained by a structure whereby the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.
The Board of Commissioners found that adopting the federal definition of 50% provides the correct balance between requiring homeowners to make existing structures safer from flooding and acknowledging the expense to homeowners of making a dwelling compliant with current floodplain development standards.
ExemptionsAccording to FEMA, certain lateral additions are not considered substantial improvements to an original structure if no structural modifications are made to the common wall or roof of the original building. Marion County has chosen to continue to apply this policy and certain lateral additions do not require the existing building be considered substantially improved and modified to meet current floodplain development standards.
Development Not Requiring an Elevation CertificatePreviously, the County had amended the Rural Floodplain Overlay Zone to exempt certain types of structures from the requirement to obtain an elevation certificate. This is based on guidance from FEMA of structures for which federal law does not require an elevation permit. The Board adopted the same change into the Urban Floodplain Overlay Zone to be consistent and to ensure requirements are the same for property owners whether they are developing in the urban or the rural area of the county.
Unless requested by FEMA, elevation certificates would not be required for the following uses:
1. Water dependent uses, such as boat ramps, docks, wells and well covers.2. Improvements resulting from cut or fill operations, such as berms, bank improvements, ponds and dams. 3. Small scale facilities necessary to serve other uses, such as kiosks and open picnic shelters. 4. Grading, such as for roadways, even where alteration of topography occurs. Floodplain Elevation Certificates - a list of FEMA elevation certificates (by address) submitted since 1979 for construction in the Marion County Special Flood Hazard Areas. Please note this does not include property inside any city within Marion County."Important Information for People Living In or Near Floodplains" - Useful information on recent flood events, causes of flooding in Marion County, flood insurance, flood safety tips, and a list of contacts."Purchasing Flood Insurance" - a handy reference guide on flood insurance requirements and procedures including obtaining insurance if your property is not in a designated flood area and a list of information the Planning Division provides."Information About Flood Insurance" - brochure produced by the Planning Division with general information on flood insurance and how it works, mandatory purchase requirements, and purchasing flood insurance when your property is not in a floodplain.