The Mississippi River is changing, and it’s only making towboat captain Jeremy Runde’s job all the harder.
For 28-day stretches, Runde, a resident of Dubuque, is responsible for navigating a craft the size of three football fields down the river. Weighing more than 1,000 loaded semi-tractor trailers, the barges he tows up and down the waterway carry in them fertilizer, salt, corn and beans.
Simply steering the gargantuan vessels through the river’s various channels and under its bridges is already work enough, but Runde believes the water he has to contend with has only become more treacherous during his 16 years as a towboat captain.
“I notice that the river is going up and down faster, especially in these last five to 10 years,” Runde said. “It definitely makes the job harder. When the water is high, the current really tries to take you, and you have to be careful.”
Runde’s perceptions of the Mississippi River changing aren’t unfounded. Over the past few decades, severe flooding on the Mississippi River caused by heavy rainfall has become more prevalent, interspersed with prolonged periods of drought.
James Boulter, a professor at the University of Wisconsin-Eau Claire who studies the climate in the Midwest, said, since the mid-1970s, the average annual rainfall in the Upper Mississippi River Basin has increased by about one inch per decade, while the frequency of two-day heavy rainfall events has increased by 30%.
“We are regularly experiencing extreme rainfall events that aren’t extremes anymore,” Boulter said. “Record-breaking flooding is becoming more and more common.”
Tri-state residents throughout the area have personally seen the increase in flooding. Just last year, the Mississippi River experienced flooding for 85 days in Dubuque. This year, the river has experienced drought conditions, driving river levels to extreme lows. However, Boulter said both flooding and drought are largely the result of the same thing, climate change.
“With climate change, we are seeing increased incidents of flooding and of drought,” Boulter said. “As time goes on, projections show that this will only become more common.”
And, while the impacts on climate change will be felt throughout the Midwest, it is people like Runde who work or play or live on the Mississippi River that will feel the impact of climate change the most.
“The people that are already connected to the Mississippi River in some way are already feeling it, whether it be farmers living on the river bottoms or boaters,” said James Angel, climatologist with the Illinois State Water Survey. “It’s really making their lives more challenging.”
The science of climate change
The explanation behind climate change’s impact on the Midwest is complex, particularly when trying to explain how it can cause both flooding and drought, Boulter said.
The main reason for the increases in these weather events lies in the increasing average temperature of the planet. The Midwest is getting hotter, Boulter said, about 0.4 degrees hotter per decade. While these temperature changes might appear insignificant, the actual impact they have on the natural world is substantial.
“When the atmosphere heats up, there is more and more evaporation, and the air holds more and more water,” Boulter said.
In effect, the amount of water being stored in the atmosphere at one time is increasing, Angel said, which in turn leads to more severe rainfall events.
“When you have that increase in temperature, the water content in the air can go up,” Angel said. ”Once you add more moisture in the atmosphere, that’s more water for any passing storm to tap into and create more rain events.”
The result, Boulter said, has been an increase in prolonged, extreme weather events, with the increased evaporation creating drought conditions in-between each rainfall, and the current trend is expected to become more prominent in the coming decades.
These temperature increases are being primarily seen during the winter and spring months. Olivia Dorothy, director of the Upper Mississippi River Basin for the non-profit organization American Rivers, said the temperature changes are resulting in shifts in season durations.
“We are already seeing a trend of shorter winters,” Dorothy said. “A lot of storms that should have been snowfalls are instead becoming rainfalls.”
Climate change models estimate that the temperatures in the Midwest could increase by 4-5 degrees by 2050, which in turn will lead to even more rainfall. Boulter said the next three decades could see a doubling or even tripling of extreme precipitation events in the Midwest.
“We’ve actually seen some of that already,” Boulter said. “There has already been an increase in five-year record rainfalls in these past few decades.”
Boulter acknowledged that the predictive accuracy of the current models is limited in their ability to accurately project how the climate will change in the next few decades. However, he said there is little doubt that temperatures will rise, bringing more rainfall events.
“We can tell you that temperatures will increase,” Boulter said. “There is just a limitation in knowing how much it will increase because of computing power.”
The economic impact
These changes in temperature have already had significant impact on the businesses and industries that operate on the Mississippi River.
The U.S. Fish and Wildlife Service estimates that the upper Mississippi River Basin generates about $253.2 billion in revenue and supports about 750,000 jobs. The transportation of goods by barge makes up a significant facet of river commerce. According to the U.S. Department of Transportation, about 763 million tons of cargo are transported by barge every year.
However, instances of extreme flooding can completely halt barge traffic. Tom Heinold, chief of operations for the U.S. Army Corps of Engineers Rock Island District, said all barges traveling up or down the Mississippi River must pass through the numerous lock and dams located on the river. When the river is flooded, locks often are required to close.
“We’re not immune to weather extremes,” Heinold said. “If the water gets too high, then barge traffic simply has to stop.”
Heinold said the price of closing down barge traffic is significant. Along with the cost incurred from the delay in delivering goods on time, towboat companies also incur substantial losses when a barge is forced to sit and wait for the water to go down.
“A tow eats up about $10,000 a day to operate,” Heinold said. “When you have five to 10 vessels waiting at one lock for multiple days, those costs add up quick.”
Last year, Heinold said many locks were forced to remain closed for months. The impact on the economy was quickly apparent. The prices on fertilizers increased by nearly 30% in the spring, according to the U.S. Department of Agriculture. Heinold said numerous consumers were directly impacted by the flooding in 2019.
“Nothing was getting where it needed to go, so you were seeing premium prices for things like corn and soy beans,” he said. “Every day, people were unable to sell their products or windmill blades weren’t able to get installed because the river was too high.”
While the locks did eventually reopen the costs of the 2019 flooding are still mounting in 2020. Heinold said many Mississippi River channels were filled with thousands of tons of sediment by the flooding. With the drought conditions incurred this summer, the U.S. Army Corps of Engineers has been forced to spend millions of dollars in dredging out the channels to ensure boat traffic can continue.
“On a normal year, we would usually spend about $2 million on dredging,” Heinold said. “This year, we’re pushing $7 million just to make sure we can keep the river open. We were at times just days or weeks away from a river closure because the water continued to drop.”
The combination of severe flooding followed by a year of summer drought created significant challenges for the U.S. Army Corps of Engineers, something Heinold notes has become increasingly frequent.
“We don’t know what normal is anymore,” Heinold said. “It used to be, 15 or 20 years ago, that a flood was the exception. Now, we’re having floods in November and December or extending past spring into the summer. The extremes seem to be the new norm.”
While the larger economic forces of the Mississippi River have already felt the impact of climate change, smaller, local business have experienced it as well.
Throughout the Dubuque area, rampant flooding of the Mississippi River also incurs severe monetary costs for local businesses.
Jamie Becker, co-owner of Dubuque Marina, said the channel leading from the Mississippi River to her business is regularly filled in with silt and sand from flooding, bringing with it the cost of dredging out the channel to make it accessible for boaters. Last year’s flooding combined with this year’s drought has only exacerbated the issue.
“It’s going to cost us hundreds of thousands of dollars to dredge out the channel,” Becker said. “We just dredged the same area a few years ago for over $100,000, and here we are, doing it once again.”
The impact to marinas extends beyond just dredging, Becker explained. This year, the depth near her fuel dock was so shallow that it was inaccessible for several weekends, leaving the business unable to sell fuel. Becker said she is aware that flooding incidents similar to 2019 are only expected to become more common, and she fears the costs will impact river industry.
“It will only get worse every year,” Becker said. “It’s going to cost a lot for marinas and cities.”
Jeremy McDowell, owner of Midtown Marina, said his business purchased their own dredging machine, a significant investment, but one he feels will become increasingly necessary for marinas in the coming years.
“You never get over the initial cost of one, and then you have the permits and the fuel costs,” McDowell said. “But, they allow us to maintain our channel, so it’s something that we have to do.”
Angel said numerous other industries have been impacted by Mississippi River flooding caused by climate change, particularly farmers. The USDA estimates that nearly 20 million acres of farmland was left unplanted because of springtime flooding.
“Farmers that farm along the Mississippi River bottoms have had a lot of headaches in the last several years,” Angel said. “It’s preventing them from planting their crops on large portions of land.”
The impact on river recreation
While the increase in flooding has already hit businesses on the Mississippi, the many people who utilize the river for weekend boating or fishing will also be impacted by the changes in climate as well.
Dorothy said more frequent flooding results in less days in the spring and summer to safely boat. When the water depth is at adequate levels, there is still likely to be increased amounts of debris in the water that could potentially damage vessels. During periods of drought, boaters are instead faced with running ashore on sandbars. These are hurdles that many boaters have already contended with, but Dorothy stressed the climate change will only render occurrences as more common.
“It will become problematic for recreational boaters,” Dorothy said. “The river is going to be more challenging to navigate.”
Fishing is also expected to be affected as climate change alters the seasons and water temperatures. As they continue to warm, Angel said the upper Mississippi channels are likely to see the increased presence of species typically found in the south. Other cold-water fish species, such as the yellow perch, will see their numbers decline as shorter winters lead to briefer mating seasons.
“These small changes in temperature can have a substantial effect on the ecology of a river,” Angel said. “I think people who fish are going to begin seeing different trends in the kind of fish they are catching on the river, and that is largely because of climate change.”
One species the changing climate will help are mosquitoes, Angel said. The shorter winters will allow for longer breeding periods for the insects.
“Insects like mosquitoes and ticks like these changes in temperature,” he said. “That is particularly unfortunate.”
Preparation for the future
Climate change’s impact on the Mississippi River and the peoples’ lives tied to it will be gradual but significant. Along with the physical changes the river will undergo, the economic damage that comes with it is already altering the lives of those that rely on the river to make a living.
Dorothy said the current trajectory of the climate largely points to these changes being irreversible.
“It’s one of those things where you hate being right,” she said. “It is impacting peoples’ livelihoods, and it can’t be stopped.”
However, Boulter said more can be done to reduce how much the weather increases over the next three decades. There are still best-case scenario projections indicating that reductions in greenhouse gas emissions can slowdown the rate at which the temperatures in the Midwest rise.
These changes would need to be significant, he added, but they are possible.
“A state like Iowa can be part of a global solution,” Boulter said. “Things like investing in renewable energy or reducing carbon emissions through agricultural practices is all a step in the right direction.”
At the same time, though, the changes to the Mississippi River will require adaptation. Those that work and play and live on the Mississippi are going to experience a river that is changing, and they are going to have to change with it.
Many of them already are.
“The job has gotten more challenging,” Runde said. “We’re getting more high water out here, but you just have to deal with it. That’s all you really can do.”