Flooding is now a certainty in the Red River Valley

Even before Thursday's snow, flooding in the Red River Valley was likely this spring. Now you can bet on it, particularly in rural areas.

River levels well above flood stage and overland flooding are now a certainty, according to the latest three-month outlook from the North Central River Forecast Center, which monitors rivers across nine Midwest states and into southern Canada.

"Even if we get an ideal melt now, we're still going to see flooding," said hydrologist Steve Buan.

The Red River Valley, a broad, flat area along the Minnesota-North Dakota border, had record autumn rains, some of which still remains frozen in ditches, clogging culverts and other outlets. Deep snows have fallen on top of that, particularly in North Dakota, where snow along some tributaries to the Red still holds the equivalent of 5 inches of water or more.

The river agency's March-through-May outlook indicates "major" flooding will occur in Fargo and several other locations along the Red. But many of the larger cities have installed multimillion-dollar flood protection projects in recent years and aren't expecting any calamities like those of recent years.

"We haven't bought any sand," said Moorhead, Minn., operations manager Chad Martin.

A "major" flood at Fargo-Moorhead occurs when the Red hits a 30-foot mark; Martin said the city would start building temporary dikes when it hits 37. Its record crest was 39.5 feet at Fargo-Moorhead in 1997. That later wrought $2 billion in damage downstream in Grand Forks.

Overland flooding -- from melting snow that can't soak into frozen soil or into plugged-up ditches -- will likely wash out roads and dislocate residents in areas unprotected by dikes, Buan said. Martin said Moorhead itself is well-protected by large diversion ditches against a rear-guard action by overland flooding.

The U.S. Army Corps of Engineers will initiate this year's first flood-mitigation effort Monday by beginning to draw down water levels in Lake Traverse, near Wheaton, and the Orwell Reservoir in Fergus Falls, to make room for more water and keep it from running into the Red.

The drawdown was triggered because Thursday's snow brought the water content of snow on the ground in the area to about 3 inches, said Tim Bertschi, the corps' Red River basin operations manager. The drawdown will be twice the volume of a normal spring action.

"This is as far down as we can take both these lakes," Bertschi said.

Bill McAuliffe • 612-673-7646