Severe Flash Flooding in central and southeast Illinois June 17 - 18th
A series of very slow moving thunderstorms, which developed along a nearly stationary front and remnants of an outflow boundary from previous storms, produced copious amounts of rain in much of Morgan County and western Sangamon County from late in the evening June 17th into the early morning of June 18th.
Weather observers in the area of the heaviest rainfall all reported between 4.50" and 6.00" of rain (see map below). An official weather observer 2 miles east of Jacksonville (JAXI2) reported a storm total of 5.60" of rain.
Doppler radar estimated that even heavier rainfall amounts occurred in eastern Morgan county into parts of western Sangamon County with totals in excess of 8.00" of rain. This included an area from Lake Jacksonville through Franklin to just west of Loami, through New Berlin to Alexander where all rural roads were closed, farmland was underwater and homes were flooded. (See the radar image below).
The city of Jacksonville was significantly impacted with flooding at the water treatment plant, and the loss of water services to the city. In addition, most roads in the eastern and northern parts of the city were impassible, residents of a mobile home park were evacuated, numerous automobiles were stranded, several hundreds of basements were flooded, and a section of I-72 was closed.
Flooding and stranded car on Poor Farm Road in Morgan County
Photo courtesy of Morgan County EMA
The heavy rain and runoff from the creeks and streams in Morgan County resulted in a levee breach on the Mauvaise Terre Creek near the northern Scott County town of Oxville. This closed several roads between Oxville and I-72, and resulted in the evacuation of much of Oxville.
In western Sangamon County, barns were reported to be underwater, most roads were flooded and impassible, and the Sangamon County Fair was impacted. Tragically, a 75 year old man from Chatham died on a road just east of Loami when his vehicle was swept away by floodwaters from Lick Creek.
In addition, 2.00 to 4.00 inches of rain also occurred in southeast Illinois from Effingham County to Lawrence County. Many streets in Effingham were flooded during the early morning of June 18th. Rural roads across southern Richland County into Lawrence County were also impassible due to the flooding.