How the FM Area Diversion Comprehensive Project Will Work

Greg Thompson: Hi, my name is Greg Thompson. I’m a civil engineer and certified floodplain manager. Today, I’m going to provide an overview of the FM Area Diversion project and its operation.

Six rivers contribute to flooding in the Fargo-Moorhead area, all generally moving south to north: the Red River, Wild Rice River, Sheyenne River, Maple River, Lower Rush River, and Rush River. The diversion project is designed to provide certifiable flood protection from all six sources.

Major Project Components:

• The Diversion Channel: A 30-mile long channel, approximately 20 feet deep and 200–300 feet wide at the bottom. It includes aqueduct structures on the Maple and Sheyenne rivers that act like interstate overpasses, allowing normal flows to enter the protected area while diverting excess floodwater.
• The Southern Embankment: A 20-mile stretch designed to regulate water flow into the metro area and direct it into the channel. It includes three gated structures: the Diversion Inlet, the Wild Rice River structure, and the Red River structure.
• In-town Levees: These levees and floodwalls allow the project to be certifiable for a 100-year event while passing a river stage of 37 feet through town.

Project Operation:

The project only operates when flows coming into the project exceed 21,000 cubic feet per second (cfs)—roughly a 20-year flood event. During operation, the gates pass a specific design flow through town (37 feet for a 100-year event, or 40 feet for a 500-year event).

Any excess flow is passed into the diversion channel. Once the upstream mitigation area (UMA) pool begins to recede, the gates return to their original position in preparation for the next flood event. This robust project provides permanent protection for the Fargo-Moorhead metro area.