Missouri River Basin Conditions Update
Above-average temperatures in February melted much of the snow in the Dakotas. With that, there is little risk of flooding along the upper Missouri River this year. The Army Corps of Engineers reports that snowpack in the mountains has increased recently, but much of the snow in the northern plains has melted, which makes flooding this spring unlikely. The Corps did say that weather this time of year can be very unpredictable so they will continue to monitor weather patterns.
In late February, mountain snow totals above Fort Peck in Montana were 7 percent below the long-term average for this time of year. Snow is melting a bit slower in North Dakota, where up to 6 inches of water content remains in areas of the north-central part of the state. That is 28 percent more than average for the reach between Fort Peck Dam in Montana and Garrison Dam north of Bismarck.
The Corps announced that the full flood control capacity of the Missouri River mainstem reservoir system is available for this year’s runoff. The Corps’ 2017 estimate of total runoff above Sioux City is 26.2 million acre feet (MAF) – 103 percent of the average 25.3 MAF. The Corps expects to see above-average runoff through April from plains snowmelt. Runoff into Fort Peck reservoir is expected to be below average this spring due to the lower than average mountain snowpack. Snowpack in the upper Platte River basin is above average.
Projections show a slight-to-moderate risk of flooding along some of the Missouri River tributaries this spring. There is an increased risk for flooding in the northern Red River Valley in North Dakota and Minnesota, and projections show near-record runoff for the Devils Lake basin in northeastern North Dakota. Both of those watersheds are outside of the Missouri River basin.