Questions and Answers on FEMA Floodplain

September 29, 2023 River | Lowry Engineering

What is the 100-year FEMA floodplain?
The 100-year floodplain is an estimate by FEMA of the land inundation (or overflow) area of the 100-year flood event. You can think of it as the elevation the water will rise to in this event.

What is a 100-year flood event?
This is an event having a 1% probability of occurring in any given year, meaning the chances of a flood of this magnitude occurring is once every 100 years.

Is my property in the 100-year FEMA floodplain?
The FEMA Flood Map Service Center is a good place to look for floodplain information. On this website, you can search for a location on the map and it will provide links to any available flood map and report. We can use these to help identify if a property or portion thereof is in the floodplain, and if so what the 100-year flood elevation is. Furthermore, some cities (including City of Fargo) have the floodplain shown on their City GIS system.

I keep hearing about a 41’ Inundation Level in the City of Fargo. What does this mean?
This is in reference to the flood water reaching a level of 41’ on a gauge located in town along the Red River. The City can then define what actual elevation flood water around the City would be if the Red River water is at 41’ at this specific location. This elevation is higher than the FEMA 100-year flood elevation by roughly 1 foot but varies around town. For reference, the highest recorded level in the City of Fargo was 40.82’ during the 2009 flood.

How high do I need to build in the City of Fargo?
The City of Fargo requires a building’s lowest opening elevation shall be set to either 2.0’ above the FEMA 100-year flood elevation or 1.2’ above the Fargo 41’ inundation level,whichever is higher.

I have more floodplain questions. What should I do?
Reach out to Lowry Engineering at 701-235-0199 or info@lowryeng.com. We would be more than happy to discuss floodplain development with you.