As temperatures increase worldwide, wetter winters could lead to flooding problems in the Midwest .

According to Indiana University environmental and geological scientists Matthew Auer, Gabriel Filippelli, and Greg Olyphant, many cities and towns in the Midwest lack adequate infrastructure to cope with the higher volumes of rainwater headed our way.

“Climate change models suggest more rain and bigger storms," says Auer, a professor of public and environmental affairs at IU Bloomington. "During the growing season, a sizable volume of rainwater can exit the system as water is taken up by trees and vaporized out of leaf surfaces. But in the winter, broadleaved trees are leafless. Less water leaving through trees means more water on the ground.”

Colder ground also means lower infiltration of rain into the soil, according to Filippelli, chair of the geology department at IUPUI. These conditions are especially problematic during sudden, intense downpours – which Filippelli said will be more frequent in coming years.

“We expect ‘flashier' precipitation, with rain dumping down quickly and without warning, as opposed to slow and constant drizzle,” he says.

Without absorption into soil, water moves into streets and sewage systems in high volume.

“The biggest risk for cities like Indianapolis is of overwhelming the sewage system,” Filippelli says. “The way our system is built, in the event of heavy precipitation, the system drains directly into the river. That's the export of nearly raw sewage into river systems that flow down throughout the state. This creates a very serious health risk for humans, especially in the form of E. coli bacteria.”

Other cities, including St. Louis , have equally antiquated systems, he says. Auer added that many smaller towns along the Mississippi and Ohio rivers have no flood controls at all.

“In Louisiana , they had at least invested in a levee system, although of course it wasn't enough. But along the upper Mississippi and the Ohio River , you have a lot of little towns that are vulnerable to floods, and there is nothing to protect them,” he says.

Olyphant, a professor of geological sciences at IU Bloomington who specializes in hydrogeology, says that state and regional efforts have barely begun to address the problem.

“To my knowledge, no new efforts to abate flooding have been initiated beyond the ongoing attempt to decrease runoff from agricultural areas and strict regulation of any proposed floodplain alterations,” he says. “What should be done -- but is not likely -- is re-establishing wetlands, especially riparian wetlands in the big river valleys, because they are nature's way of mitigating floods. Also, we should be slowly moving development, especially cities, away from floodplains – they have that name for a reason. 

“It seems these obvious lessons are not being learned, as in the case of New Orleans ,” Olyphant says, “so expect to see more problems in our big cities as we continue to develop close to rivers and oceans and at the same time alter both the climate and hydrologic budget of the earth.”