Flash Flood in Champaign County, Illinois

Periods of thunderstorms with heavy rainfall produced rain rates of 1 to 2.5 inches for at least two hours from 0630-0830 LST in northwest and central Champaign County - including the cities of Champaign and Mahomet/Lake of the Woods. The highest rain totals ranged between 6.00 to 7.00 inches from Mahomet to the village of Foosland. Nearly all rural roads in northwest Champaign County were flooded with at least a foot of water. Illinois Route 47 from Gibson City to Mahomet, U.S. Highway 150 from Mansfield to Mahomet, and U.S. Highway 136 near Fisher were closed due to flooding. Parts of Interstate 74 from milepost 168 to 173 were impassable. Numerous streets and viaducts in Mahomet and Champaign were also impassable. Many homes in Mahomet and Champaign also had significant basement flooding. Estimated flood damages in Champaign County were around $47 Million.

An upper-level disturbance interacting with a very moist airmass triggered a cluster of thunderstorms across east-central Illinois during the morning of July 12th. The storms were efficient rain-producers and tended to back-build over the same locations, resulting in 4 to 6 inches of rain from southeastern McLean County across northern Piatt County into central and northern Champaign County. As much as 7 inches of rain was reported in northwestern Champaign County around Mahomet. As a result of the very heavy rain falling in a short amount of time, widespread flash-flooding occurred. Numerous roads were closed due to flooding.