UI study finds that Midwest is experiencing more serious floods

Coralville, Iowa during the Flood of 1993. (Alan Light/Flickr)
Coralville, Iowa during the Flood of 1993. (Alan Light/Flickr)

Nick Fetty | February 12, 2015

The Midwest has seen a greater number of serious floods in recent decades compared to previous years, according to a report by researchers at the University of Iowa.

“It’s not that big floods are getting bigger, but that we have been experiencing a larger number of big floods,” said Gabriele Villarini, UI assistant professor of civil and environmental engineering and a co-author of the study.

The report – which was published this week in the journal Nature Climate Change – examined 774 stream gauges in 14 Midwestern states (Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, West Virginia, and Wisconsin). The researchers concluded that 34 percent of the sensors detected an increase in flooding events between 1962 and 2011. Nine percent of the gauges showed a decrease in flood events during that same time. The region including Illinois, Iowa, Indiana, Ohio, Missouri, and North Dakota experienced the greatest increase of flood frequency.

The authors wrote: “Most of the flood peaks in the northern part of the [Central United States] tend to occur in the spring and are associated with snow melt, rain falling on frozen ground, and rain-on-snow events.” However, the report “does not attempt to pinpoint precisely how climate change might be directly responsible for these increased flooding events.”

Serious floods have inundated the region in 1993, 2008, 2011, 2013, and 2014 and have caused more than $260 billion in damages between 1980 and 2013.

Funding for this research was provided by the U.S. Army Corps of Engineers Institute for Water Resources, the Iowa Flood Center, IIHR-Hydroscience & Engineering, and the National Science Foundation.

High rainfall may lead to record flooding in Northwest Iowa by Saturday

Iowa Environmental Mesonet graphic of rainfall totals from 6 a.m. June 15 to 6 a.m. June 18.
Iowa Environmental Mesonet graphic of rainfall totals from 6 a.m. June 15 to 6 a.m. June 18.

With sections of Iowa seeing as much as ten inches of rain over the last 72 hours and more rain in the forecast, Iowans are bracing for record flooding and water damage across the state.

The National Weather Service predicts the Big Sioux River at Sioux City to reach dangerously high levels by Saturday, topping out at 109 feet, 0.7 feet higher than the record of 108.3 feet set in April of 1969. Once the river level reaches 108 feet, sandbagging will be required to protect Interstate 29 from flooding.

Big Sioux River level predictions for this week (National Weather Service)
Big Sioux River level predictions for this week (National Weather Service)

The predictions come at a time when Northwest Iowa is already overwhelmed by rainfall, with a levee break in Rock Valley Tuesday causing the city to lose power to three of its four wells and inundation of drinking water treatment plants putting the area under a boil warning. The city is currently under a state of emergency.

The Iowa Flood Center’s Iowa Flood Information System (IFIS) currently lists areas along the Big Sioux River under a Major Flood Stage, with Des Moines, Cedar Rapids and Iowa City areas also at risk. Continued rainfall this week will continue to raise water levels across the state. To see current levels and real-time information on Iowa’s rivers, visit the IFIS website.

Western Iowa to produce more Wind Energy

A portion of the World's largest windfarm. 259 wind turbines over 200 feet tall located in Cherokee and Buena Vista Counties in Northwestern Iowa. Together they produce 192,750 kW of energy. Photo by Jim Hammer, Wikimedia Commons

Western Iowa will soon get a wind energy boost.

MidAmerican Energy announced today that it will buy 258 turbines for new wind farms in Adair, Adams, Calhoun, Cass and Marshall counties, the Des Moines Register reports.

The turbines will provide electricity to about 1.4 million customers in Iowa, Nebraska, Illinois and South Dakota by 2012.