Last week’s bitter cold weather left a lot of ice floating on the Missouri River. In years past, the river froze solid during the winter, but that was before the U.S. Army Corps of Engineers made it a more navigable waterway.
Jody Farhat, chief of the Corps’ Missouri River Basin Water Management Division based in Omaha, says much has changed over the decades. “The navigation channel is more confined so we’re concentrating the flow into a narrower channel,” Farhat says. “It’s deeper and narrower even during the winter period, where back a hundred years ago, it was a wider, shallower, meandering sort of channel.”
Water flows from Gavins Point Dam at Yankton, South Dakota, have been cut back this season in anticipation of the weather in the year ahead, but Farhat says that closely-regulated flow still has an impact far downstream. “The reservoirs are used to supplement the releases during the winter period,” Farhat says. “Even though we’re doing minimal releases this winter, there’s more water flowing today in the river during the winter than there would have been back a hundred years ago.”
Many riverside communities rely on water from the Missouri River year-round, as do utilities like the Fort Calhoun Nuclear Generating Station near Omaha.
“When we see that really cold weather come into the basin, we try to up our releases a couple of days in advance so the water’s there in the channel,” Farhat says. “Our goal is to keep those water intakes, the municipal, industrial and power plant intakes, operating during this winter.”
Water temperatures in the river are hovering just above freezing, perhaps as low as 32.1 degrees, she says. The river might see ice jams or ice dams today, but it won’t freeze over for long stretches any more, as it did decades ago.