Corps Raises 100-Year Flood Estimate for Fargo, North Dakota

The U.S. Army Corps of Engineers has raised its 100-year flood estimate for the Red River in Fargo and neighboring Moorhead, Minn.

The change raises the previous estimate about a foot to 42.6 feet.

The new estimate was based on the amount of water flowing through the Red River, how often it floods and how high the water rises as it flows through the cities, said the corps’ Craig Evans. It takes into account last year’s record flooding.

The corps had set the estimate at 39.3 feet based on an analysis of Red River basin records dating back to the late 1800s. But, Evans said, the Fargo-Moorhead area has been plagued by wet conditions since the 1940s, so the corps worked with a panel of experts to come up with the new estimate accounting for the wet period.

Evans called it an unusual move for the corps, and one that doesn’t translate to other cities along the Red River.

“It’s something that seems to be occurring at Fargo and Moorhead that isn’t necessarily transferable to any other place,” he said.

The cities have faced major flooding the past two springs.

The river crested March 21 in Fargo-Moorhead at just under 37 feet, or 19 feet above flood stage. No major damage was reported, though the crest was the seventh highest in recorded history.

The record was set in March 2009, at 40.84 feet. Thousands of people were evacuated and about 100 homes flooded.

The corps is studying proposed flood diversions on both sides of the Red River.