When it rains it pours
It seems hundred-year floods are becoming a common occurrence in Cape Girardeau and other places around the nation.
According to Kellerman Foundation for Historic Preservation historian Frank Nickell, a retired professor of history at Southeast, the Mississippi River drains about half of America’s water.
“It’s part of the natural environment here in the center of North America,” he said.
Cape Girardeau constructed a downtown flood wall in 1964 to protect itself from the seasonal rising waters of the Mississippi River and has seen it serve well. According to an Associated Press story in 2016, all but five of the 32 highest crests recorded in Cape Girardeau County have occurred since the record-setting 1993 flood, and four of the top 10 have happened since 2011.
This year, the Mississippi has again reached flood levels and the National Weather Service has said the risk of major flooding will persist through May.
Southeast geology professor Kate Perkins teaches about natural geologic environmental hazards, including flooding.
Perkins said a combination of factors, including the routing of ice melts in the northern states and restrictions on the natural flow of the Mississippi River, have conspired to create problems.
“There may be a point where we need to re-evaluate our flood control systems and possibly give the river a place to go,” she said. “Instead of continually building levees up, we may have to say, ‘OK, [floods] are overtopping levees. They’re getting too close to the top of the floodwalls.’”
Her suggestion for the dilemma? Setting aside a section of land for the river to flood into when it gets high — at least then the river won’t be going up, it’ll be spreading out.
“When you put in the additional climate change, with urbanization, with already saturated soils that are just beyond its holding capacity, [the water] has got to go somewhere,” Perkins said. “And it goes into the drainage systems. And what do you do with all that water? You open the dams and you let it go down the river, but unfortunately, that’s going to cause flooding for people. So we try to contain it through levee systems and letting a little bit out at a time to regulate any potential flooding.”
Southeast professor Indi Braden teaches agriculture courses at the university and her main teaching focus is on agronomy (crops and soils), precision agriculture and sustainable agriculture (agroecology).
Considering how many agriculture students there are at Southeast who may encounter flooding challenges, Braden said she tries to connect current events such as the Nebraska flooding to her coursework.
The recent flooding in Nebraska definitely has an impact on the crops, Braden said, not only in that region but in the Southeast region as well.
She noted the flooding moved large amounts of soil downstream, including topsoil, nutrients, soil structure and microorganisms, all of which will eventually reach the Gulf of Mexico.
“For farmers downstream, the flood water carrying soil, nutrients and debris will continue to make its way down the Missouri River to the Mississippi River and finally to the Gulf of Mexico,” Braden said.
The flooding also has had an impact on Midwest grains, she said.
“Consumers and agriculture commodity markets will also feel some impacts from the flooding,” Braden said. “Many Nebraska, Iowa, and northern Missouri producers have seen damage to grain bins full of grain, which will not make it to market.”
Farmers will also feel a direct impact from the flooding that’s occurring, Braden said, and while it brings challenges to them, “the field of agriculture is a combination of science, business, art—full of knowledge, experience, faith and risk.”
“When nature doesn’t cooperate with cropping plans, farmers will adjust if they can,” Braden said.
Perkins relates to the farming aspect of the flooding issue as she owns and works on one herself. She personally knows farmers who’ve lost their livelihoods because of flooding.
“There’s a reason I commute 45 minutes to get here. I have a farm and I live on high ground. I will never live on a floodplain — I like high ground for a reason,” Perkins said.
When it comes to global warming, Perkins said society often mistakes it for warmer weather.
“The climate is changing,” she said. “Now, I hate to use the words ‘global warming,’ because everybody thinks, ‘Oh, here I am buried in 30 feet of snow. Where’s the warming?’ But people need to understand that when we increase heat in our atmosphere, heat is energy.”
She said that energy changes circulation patterns, and the energy is then getting fed into storms. Perkins added with the energy change comes seasonal change in weather.
“So when we're dealing with that change, we can see seasonal stuff like our spring rains get incredibly intense and dump too much water,” Perkins said.
She explained how the rain and snowfall in northern parts of the country can have an effect on the Southeast region. But she also said it’s all part of a normal, natural cycle — the hydrological cycle. If it was left alone it could spread out and flood the area, but that’s not a possibility because “people live where they live.”
“We have all this snow up north melting and then being fed into the major drainage basin — the Red River area, the entire Mississippi River basin is huge,” she said. “You can be all the way out in South Dakota but that snowmelt is eventually going to reach us through all the drainage systems that feed into the Mississippi River. But it takes time, and that’s called ‘lag time.’”
She noted that it takes 10 inches of snow to make up for one inch of water.
All the record snowfall in Montana and South Dakota has to go somewhere, and the flood control systems lead straight through the Mississippi River, Perkins said. The more drainage systems there are, the more water there is fed into the Mississippi.
Perkins said the U.S. has gone through several “hundred-year floods” in the last 15 years, and she’s predicting it will continue. A hundred-year flood isn’t something that occurs once every 100 years as is commonly mistaken, she added.
“They talk about the hundred-year flood as something that only occurs once every hundred years. It’s all statistics,” she said. “[It’s] a 1/100 chance it’ll happen in a given year. So there’s a 99% chance every year that it’s not going to happen. But that 1% chance has been happening more frequently.”