There was a Chicago River reversal this morning at the Wilmette Pumping Station to Lake Michigan. Several inches of rain fell in a short amount of time late last night and early this morning. The reversal occurred from 2:30 a.m. to 5:45 a.m. The last reversal was Oct. 3, 2019, and prior to that a reversal had not happened since October 2017. 

 This storm overnight comes after heavy rain on Thursday. According to the National Weather Service (NWS), approximately 3.53 inches of rain fell in the Chicago region on Thursday but some totals were in excess of 4 inches in parts of the Chicago metro area, including the official measurement at O’Hare International Airport. The heavy rains led to flash flooding and impassable roads, the NWS stated.

MWRD water reclamation plants (WRPs) and the MWRD’s Tunnel and Reservoir Plan (TARP), consisting of 109 miles of tunnels and three reservoirs, are working around the clock to keep up with the flow. The water from these reservoirs will be pumped back to MWRD WRPs for treatment when conditions permit.