FORT WAYNE – If it seems as if Midwestern weather is more extreme and thunderstorms are more often bigger, stronger – and rainier – it’s because they are, a new study says.
Examining 50 years of precipitation records, the Rocky Mountain Climate Organization and the Natural Resources Defense Council’s report, “Double Trouble: More Midwestern Extreme Storms,” says the number of large storms per year – those dumping 3 or more inches of rain in 24 hours – has doubled in the past 50 years.
That kind of heavy rainfall has led to devastating flooding across the Midwest, the study says, with the two worst years for extreme storms, 2008 and 1993, being the years with the region’s worst floods in decades, causing $16 billion and $33 billion in damages.
The 2008 flooding devastated Columbus, Ind., filling the first floor of Columbus Regional Hospital with water, flooding 15 percent of the buildings in that city and killing two people.
There was also flooding in Fort Wayne and on the lakes of Noble and Kosciusko counties that year.
Matthew Wirtz, director of engineering for Fort Wayne City Utilities, said he has seen similar studies and seen it in daily experience – City Utilities has been studying rainfall patterns to help it design $240 million in projects to prevent rainfall from washing raw sewage into the rivers.
“We’re seeing those patterns and that impacts things we’re doing as well,” Wirtz said.
He said the highest river levels recorded over the past 100 years have almost all been in recent years, but so have the records for lowest river levels, meaning all types of weather seem to be getting more intense.
That affects taxpayers directly, because when huge amounts of rain fall, the storm sewers can be overwhelmed, and they wash the sanitary sewage out into the rivers, polluting them with millions of gallons of waste.
Under a federal consent decree, the city has agreed to spend $240 million to prevent the pollution in return for not being sued for damages. The money will go to projects ranging from increasing capacity at the sewage plant to storage ponds to hold the overflows to massive underground tanks for holding rainfall, separating sanitary from storm sewers, and increasing capacity across the city system. All of those projects must be sized to deal with the new, larger rainfalls.
“Floods are to the Midwest what hurricanes are to coastal areas – the region’s most widely destructive type of regularly occurring natural disaster,” the report says. “Since 1980, only seven hurricanes were costlier than the flooding of 2008, and only two – Katrina and Andrew – were costlier than the Great Flood of 1993.”
Karen Hobbs, senior policy analyst at the National Resources Defense Council, said most cities are just not equipped to deal with the kind of rainfall these storms are dumping.
“The report confirms what those of us living in the Midwest have probably already guessed – that violent storms have dramatically increased in the region,” Hobbs said. “This is some really eye-opening stuff that has real consequences.”
Bob Kennedy, the city of Fort Wayne’s director of Public Works, said extreme weather has long been an issue in a city built on three rivers.
“We’re always prepared for the worst. In Indiana you never know what the weather’s going to bring,” he said.
Fortunately, he said, even in extremely hot, dry periods, the City Council understands what’s at stake.
“There’s been too many floods here for anyone to forget,” Kennedy said. “And it could start raining tomorrow – you just never know.”
The environmental groups that performed the study contend the rise in extreme storms is because of climate change.
Stephen Saunders, president of the Rocky Mountain Climate Organization and the report’s primary author, said the number of smaller storms barely changed, while the number of extreme storms doubled since 1960.
“The real story is that the increase is all stacked at the high end of the scale,” Saunders said. “That’s a far greater increase than we expected and a much more marked pattern than we expected.”