Published February 21 2013
Snowfall increases risk of major spring flooding in Fargo to 79 percentFARGO – Recent snowstorms gave a substantial boost to spring flooding chances in the Red River Valley, especially in Fargo-Moorhead, where the river’s risk of topping major flood stage jumped to 79 percent in the National Weather Service’s flood outlook issued Thursday.
The Jan. 24 outlook predicted a 6 percent chance of exceeding Fargo’s major flood stage of 30 feet.
Now, there’s a 50 percent chance the river will exceed 33.2 feet, a 25 percent chance it will top 35.1 feet and a 5 percent chance of surpassing 37.8 feet.
The Red River at Wahpeton has a 64 percent chance of major flooding. The next greatest chance for major flooding along the Red is in Pembina, at 40 percent.
“The flood risk throughout the valley is up substantially from the flood we were looking at” in January, said Greg Gust, warning coordination meteorologist at the weather service office in Grand Forks.
Fargo City Administrator Pat Zavoral said the city is well-protected to 38 feet, having spent roughly $100 million on flood protection since the 1997 flood. Fargo’s record flood crest is 40.84 feet on March 28, 2009.
If the forecast for major flooding materializes, the city will erect temporary dikes on Second Street North by City Hall and on Oak Street North near Mickelson Field, Zavoral said. Temporary levees also may go up along Drain 27 in the Copperfield Court area. Elm Street and the low-lying 12th Avenue North toll bridge and North Broadway Bridge would be under water.
The city has 750,000 filled sandbags left over from the 2011 flood fight if needed.
“Only time will tell. We can’t panic yet,” Zavoral said.
Late January and February snowstorms added significant amounts of moisture to the snowpack across eastern North Dakota and western Minnesota, especially in the southern basin of the north-flowing Red River, the weather service said.
The snowpack contains 3 to 5 inches of water across most of the southern basin, which is “well above normal” and “right up against the numbers we had back in 2009,” Gust said.
“But again, in both of those years we had substantial snowfall and rain that occurred later into March and early April,” he said.
The climate outlook released Thursday calls for a cool, wet spring with an area of above-normal precipitation in the Red River corridor in March shifting to the east in April.
Soils remain dry from drought at the middle and deep layers, but topsoil was wet from fall rains when it froze up for the winter, boosting the risk of major flooding, Gust said.
“We have a frozen ground, and we have a lot of water sitting in that snowpack, so our exposure’s high,” he said.
On the bright side, stream flows are well below normal and dry soils could soak up a lot of water if the area receives a gentle thaw, Gust said, noting frost depths are near normal this year. Recent heavy snows also have lessened drought impacts, he said.
The next flood outlook will be released March 7.
Readers can reach Forum reporter Mike Nowatzki at (701) 241-5528