Just how historic was that historic rain?
After historic flooding overtook parts of central Illinois this summer, shattering records and inundating basements, a certain Seinfeldian question could be overheard in conversation everywhere: So, what’s the deal with all the rain?
Extreme rainfall caused major flooding in the Bloomington-Normal in late June. Days later, rain that was even more extreme wreaked widespread devastation across Gibson City, 30 miles to the east. Heavy rainfall is common in Illinois, and the state has seen its fair share of extreme rain events. The record is 16 inches in Aurora in 1996. But even in a region known for rain, the unrelenting summer rains still felt like … a lot.
And as it turns out, when it comes to the feeling that lately it’s been raining more and raining harder, there’s some science to support it. State Climatologist Trent Ford said in a warming climate, there’s an increased potential for heavy rain.
“What we’ve observed with long-term rainfall records, and based on theory, what we expect is that overall warmer climate would yield — in a climate such as ours — more frequent and more intense rainfall,” Ford said.
And the climate is becoming measurably warmer. According to climate monitoring data from the NOAA Centers for Environmental Information, the average daily temperature in Illinois has increased by 1 to 2 degrees Fahrenheit. Winter and spring temperatures have risen by as much as 3 degrees. In this warming climate, extreme rain events like those that inundated the region this summer will become more common, say experts.
'We Lost Walls'
Tricia Brownfield was at home in Bloomington on June 25. It had been raining for hours. As she usually did in a heavy rain, Brownfield went to the basement to check the sump pump. She was accustomed to the basement taking on a little water in heavy rain, but she was hardly prepared for what she saw. Water building in her backyard was rising up her basement windows, pushing against the glass. She heard a loud crack and the sound of a sudden rush. 15 minutes later, the water had risen to the top of her basement stairs.
With the help of a neighbor, Brownfield and her husband gathered up their dog and fled. Brownfield was the last to leave.
“And there was a moment that I knew we weren’t coming back,” she said. They spent the night with neighbors and returned the next morning to survey the destruction.
“I saw the damage in the back and knew that it was just the window, it wasn’t just a little water. We lost walls.”
The rains that destroyed Brownfield’s home measured 10 inches over a three-day period, earning the rainfall the designation of a “100-year event.” That kind of verbiage can be misleading, according to Ford. The events are rare, “but that doesn’t mean if you get a 100-year event, you have a 100 years until you get another one,” he said.
Based on current projections, a rainfall event like the one that destroyed Brownfield’s home has a 1% chance of occurring in a given year. But as the climate warms and the atmosphere becomes capable of holding more water, the potential for heavy rain events grows. And those changes are taking place at an exponential rate.
Just days after the rains that flooded parts of Bloomington-Normal, Gibson City saw its own historic rainfall. Parts of the Ford County town recorded up to 11 inches of rain in only a few hours. Those numbers qualified the Gibson City rains as a “500-year event.”
Once in a Millennium
Allison Able was at home in Gibson City with her children as the rain fell. Within 20 minutes, Able had 8 inches of standing water in her basement. Like Brownfield, Able quickly realized she was facing an emergency. She rounded up her three daughters and two dogs and prepared to leave. But before she did, Able assembled small pile of valuables in her basement bedroom. She hoped the water wouldn’t rise all the way to her bed.
“Because this has never happened in Gibson (City) before, so nobody was prepared for this."
Those items — her late grandmother’s chest, her kids’ backpacks — were saved when the mattress rose like a raft in 7 feet of water. Everything else in the basement was gone. The family lost clothes, toys, heirlooms, and major appliances.
Able said as difficult as it’s been to confront the loss of so many things, losing their sense of security has been worse. She worries her children have developed formative memories around their experience of the flood. Able’s youngest daughter struggled to return home after the water receded. Her middle daughter gets scared when it starts to rain.
The family practices evacuating the house so that the girls will know what to do in the event of another flood. Able said there was simply no way to be ready for the first.
“Because this has never happened in Gibson (City) before, so nobody was prepared for this,” she said.
The rain that fell on Gibson City in August was unprecedented. Some parts of the area saw “1,000-year rain,” according to Ford.
“It’s very possible that I could go the rest of my career without seeing another rainfall like that in Illinois,” he said.
But precipitation is changing, Ford said. And along with it, our risk. As the climate continues to change, extreme rainfalls will become more common. A town that survives a 1,000-year rain isn't necessarily off the hook for another millennium.
And that’s why Able and her family plan their evacuation routes. So they’ll be ready if they have to escape history again.