Storms that hit McLean County on Tuesday dumped a substantial amount of rain in a short amount of time.
One location near Towanda reported over 4.5 inches of rain during the afternoon and evening hours, according to storm reports from the National Weather Service.
John Bumgardner, a meteorologist at the National Weather Service in Lincoln, noted the 4.5 inches is not an official total because totals can vary widely by location, but it's higher than official totals McLean County has seen in the last 15 years.
“It’s not unheard of, but definitely was more than we’ve had in a couple of years,” Bumgardner said.
Bumgardner said a lack of wind shear or jet stream enabled the storms to hover over McLean County for much of the afternoon.
“We were a little surprised that storms sort of merged as much as they did and coverage was as widespread as it was,” he said.
Bumgardner said the official rainfall count measured at Central Illinois Regional Airport was 1.9 inches. Higher totals were generally reported along the north end of Bloomington-Normal.
He said the storm was comparable to storms in June 2010 [officially 3.9 inches], September 2022 [3.4 inches] and September 2023 [3.3 inches].
The storms caused some street flooding in Bloomington-Normal, and McLean County was under a flood watch for several hours Tuesday night until the stormwaters receded.
Bloomington officials said the deluge of rain overwhelmed parts of the city that use combined sewer systems, which are gravity-fed rather than pressurized like water mains. Those systems can become "overcharged" during extreme downpours, leading to temporary surface flooding, city officials said.
“Our infrastructure is built to handle typical storms, but the intensity we experienced on Tuesday pushed it past its limit,” Public Works Director Mose Rickey said in a statement. “Crews were out quickly to assess known trouble spots and assist with recovery.”
Bloomington also called in special Vactor trucks to assist with stormwater management. The trucks are undergoing some maintenance and will be back in service soon to support continued cleanup and preventative work, the city said Wednesday afternoon.
Bumgardner with NWS said the rain offered a welcome relief for farmers, as the thirsty soil seemed to soak up much of the rain.
“We were starting to go into a low-end drought here in much of Central Illinois. I think the rain we had was largely beneficial, despite some of the nuisance problems we had in Bloomington,” Bumgarner said. “The crops are probably loving it.”
