Prohibited Development

Floodway

Special provisions apply to development that is proposed within the area referred to as the floodway and to any watercourse alterations within the Special Flood Hazard Area (SFHA). The floodway is the part of the floodplain that is necessary to discharge the base flood without the cumulative increase of the base flood’s elevation by more than one foot. It is specifically the areas designated as a floodway by FEMA on our locally adopted FIRM (Flood Insurance Rate Map). Generally speaking, these areas are the stream and river channels.

The floodway is usually an extremely hazardous area during flooding due to the velocity of flood waters and the debris these floodwaters carry. It is important for floodways to remain unobstructed in order to hold and convey floodwaters out of our community.

All encroachments, including fill, new construction, substantial improvements, and other development are prohibited unless certified by a registered professional engineer or architect with sufficient documentation demonstrating that encroachments shall not result in ANY increase in flood levels during the occurrence of the base flood.

Watercourse Alterations

Special requirements also apply to watercourse alterations. The watercourses that are regulated are those shown on the FIRM; they are usually labeled, such as Spring Creek. Alterations to watercourses must maintain the hydraulic capacity of the watercourse and must meet other requirements.

Is Your House Substantially Damaged?

"Substantially damaged" means that the cost to restore your house to its before-damaged condition would equal or exceed 50% of the value of your house before the damage occurred. You must check with the City’s Permit & Information Center before you build, fill, or rebuild. Floodplain building additions, improvements, and repairs that equal or exceed 50% of the value of the existing building must meet the same construction requirements as a new building. Substantially improved or substantially damaged residential buildings must be elevated one foot above the base flood elevation.

Flood Hazard Information Assistance

The City of Eugene provides free information regarding flood hazards for specific sites within the community and can answer many of your flood-related questions. Staff can assist with flood protection and mitigation design questions and with local flooding concerns. And we can make site visits.

For More Information

Anyone interested in altering a watercourse or in purchasing, developing, or redeveloping property that is even partially within the floodway is encouraged to contact Public Works Engineering staff.

The City of Eugene provides free information regarding flood hazards for specific sites within the community and can answer many of your flood-related questions. Public Works Engineering staff can assist with flood protection and mitigation design questions and with local flooding concerns. And we can make site visits.

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