Winter weather key factor in extent
After a resurgence of high waters this summer followed March flooding that prompted an evacuation of River View Park Resort and Marina and the rest of the area north of Blair known as "the bottoms," general manager Scott DeTavernier said temporary barriers were placed on the resort's property.
Though the river reached various flood stages throughout the year, DeTavernier said the barriers have kept water out. But they are only temporary solutions for a long-term problem affecting riverfront residents and farmers.
"Hopefully, we don't have to go through it again, but 80 percent sure we're going to," DeTavernier said. "Kind of too early to tell."
As the U.S. Army Corps of Engineers continues releasing water at above-average rates from Gavins Point Dam, the National Weather Service (NWS) Climate Prediction Center (CPC) predicts around a 40 percent chance of above-normal precipitation for Washington County and the rest of the Missouri River basin over the next several months.
Kevin Low, a hydrologist with the NWS Missouri Basin River Forecast Center, said above-normal precipitation this winter, or even a year of usual snow and rain, could result in many areas flooding next spring since rivers are already high and soils are already saturated.
"We need to pray for below-normal," he said. "The entire Missouri River basin is under the gun, including the Elkhorn (River). There is no room for complacency this coming spring."
Low said the extent of flooding depends on winter weather such as precipitation in the plains and mountains. But he also expects many northern rivers in in the Missouri basin to freeze at high stages this winter, which will increase the risk for ice-jam break up flooding next spring. He said rain events or brief periods of warmer temperatures this winter could create snowmelt that leads water into ice-packed rivers that couldn't carry runoff like normal.
"Thus the risk for flooding during the winter itself is increased," he said.
Saturated soils from flooding and rain this summer and fall could also increase runoff this winter and spring. The saturated soils increase the chance for deep frozen ground this winter, which rain and melting snow can easily flow over.
"The ingredients are there, just what will mother nature give us between now and March," Low said.
Frozen ground, melting snow and rain were factors in flooding throughout Washington County and elsewhere this spring. Missouri River levels have remained high as the Corps attempts to clear its dam system — six dams which run from Montana to Gavins Point in South Dakota — to its baseline flood control levels. In early October, runoff entering the system was predicted at 61 million acre feet, tying 2011's record year.
Releases from Gavins Point are now at 80,000 cubic feet per second (cfs), about twice the normal rate this time of year. The Corps plans to reduce releases to 22,000 cfs, which is 30 percent higher than the normal winter rate, by mid-December.
Eileen Williamson, the deputy director of public affairs for the Corps' Northwestern Division, said upstream river flows restricted by ice impact the winter release rate.
"If temperatures are warmer, and the river remains free of ice up north, we could slow that decline and reach 22,000 cfs a little later," she said. "Slowing the decline will allow more water to exit the system before runoff begins in the spring."
The CPC predicts around a 40 percent chance the Missouri River Basin will be warmer than normal over the next three months.
Williamson said the dam system should reach full flood control storage capacity by mid to late-January. She said the Corps plans to be more aggressive with flood control management this year as compared to last.
"We expect the soils will be saturated through the winter, which means any precipitation will translate to runoff rather than be absorbed into the soil," she said. "Because of this, we will be more aggressive in the spring as ice comes off the river to increase releases and maintain flood control storage."
DeTavernier said he hopes the Corps keeps release rates as high as it can as long as it can this winter. He said he's concerned, however, about high water should northern states like Montana, North Dakota and South Dakota have a hard winter.
John Tyson, who owns farm land near the river south of Herman, echoed DeTavernier's concern for future flooding and uncertainty surrounding winter weather.
"I guess it all depends on the weather," he said. "I don't know if anybody knows what's going to happen."
Tyson said he had 900 acres he filed for prevented planting following the March flood. Another 240 acres he planted washed out twice as the Missouri River rose and fell over the summer. He said he'd like to see the Corps make river management decisions focused more on the people living along the Missouri.
Outside of flood control, the Corps has seven other congressionally authorized purposes it attends to: navigation, hydropower, water supply, fish and wildlife, irrigation, water quality control and recreation.
For Tyson, the Corps' seven other regulatory areas compete too much with flood control. He said some structures used to divert or change river flow and other management decisions for other purposes contribute to river bank erosion, which then make it easier for floodwaters to reach further onto farm land.
"The farm land is what pays for the schools. There's the people in town, they pay some too, but the farm land is a huge part of it." Tyson said. "If that farm land is gone, guess whose going to pay for that with their taxes?"
Williamson said the Corps has in-river structures that can be modified for various reasons, including for flooding. She said the Corps has been making river management decisions based on flood control since March 2018, though its other seven congressionally authorized regulatory areas may still be served.
"For those who live and farm along the river, it is important for them to follow alerts from the National Weather Service," Williamson said. "In early February, the National Weather Service will issue its first Spring Flood Outlook,” which she said isn't new.
“But last year showed how important it is for everyone to pay closer attention to them,” she added.
Until the spring outlook is released, people who live and farm along the river have to wait and see the extent of possible flooding again this spring.
"It would be devastating if (farmers) got flooded again and again couldn’t raise a crop," Tyson said. "There'd be a lot of people who couldn't survive it."