Jan 12, 2021 4:47 PM

Missouri River levels lower, release rates near average says Corps of Engineers

Posted Jan 12, 2021 4:47 PM

By TOMMY REZAC

St. Joseph Post

Some communities in Missouri are concerned that low river levels could affect their water supply.

St. Joseph is one of them. Buchanan County commissioners sent a letter to U.S. Rep. Sam Graves, raising worries about the river level, which was 4.29 feet in St. Joseph as of Tuesday. The U.S. Army Corps of Engineers' Northwest Division calls the figure 'slightly below normal.'

John Remus is Chief of the Corps of Engineers' Missouri River Basin Water Management Division. He says the winter release rate at Gavins Point Dam in Yankton, SD are slightly lower than normal, but not dramatically so.

"We are in our winter release rate at 17,000 cubic feet per second out at Gavins Point," Remus explained. "That's slightly lower than the long-term average and the tributary inflow is a bit below normal, but it's not much below normal for winter releases."

Remus says as of now, there are no water access issues at St. Joseph or any other municipality along the river.

"But there could be," Remus says, "if we were to get an all of a sudden very cold snap that caused some ice-affected stage reductions upstream. St. Joseph, that could be at least a temporary condition there."

The full flood control capacity of the Missouri River Mainstem Reservoir System is available for the 2021 runoff season.

All 2020 flood water stored in the annual flood control zone has been evacuated as of December 21, according to the Missouri River Basin Water Management Division.

“The entire flood control capacity of the Mainstem System is available to capture and manage 2021 runoff, reducing flood risk while providing support to the other authorized project purposes," Remus said.

The current trend is quite the opposite of flood risk. Temperatures were above average and precipitation levels were below normal in summer and fall, and that's carried over into winter.

Remus says the smaller rivers and streams around the Missouri have felt the effects of that.

"Most of the tributaries west of the (Missouri) River are being highly affected by the dry soil conditions and the lack of moisture in the late summer and through the fall," Remus said.

The 2021 runoff forecast for the upper Missouri Basin above Sioux City is 90% of average. That forecast is based on significantly drier-than-normal soil conditions, low plains snowpack and below-average mountain snowpack.

"So we're a little bit lower (than average)," Remus said. "But, we still have water stored in the system that will allow us to provide full-service navigation."

Shipments through the St. Joseph Port Authority have been grounded by low water, but Remus says navigation through the river typically doesn't take place during the winter months anyway.

Studies show that flow support for Missouri River navigation will be at the full service level (9 feet deep by 300 feet wide) for the first half of the 2021 season, which starts April 1 at the mouth in St. Louis.

"But that could all change literally overnight on the Plains," Remus pointed out. "We just need to monitor that. We could have a condition where it's well-above normal runoff in the system if Mother Nature were to throw us a curveball here."

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