New storm systems move across area as alders seek mayor’s action on flooding

Thunderstorms moved into the Chicago area Monday evening, accompanied by potentially gusty, damaging winds, the National Weather Service said.

The city remains under a flood watch until 4 a.m. Tuesday with the potential for flash flooding in the overnight hours, said Kevin Donofrio, an NWS science and operations officer.

A second wave of rainfall is expected in the city with winds of around 40 mph late Monday evening. That system is expected to bring 2 to 4 inches of rain. However, parts of the southwest suburbs are at a higher risk of flooding. Drivers are advised to take precautions.

Strong winds and heavy rain over the weekend left roads flooded and thousands without power Sunday morning.

ComEd had restored power to 99% of its customers as of late Monday evening, spokesperson Brendan Recka said.

The Metropolitan Water Reclamation District of Greater Chicago on Monday, issued an “overflow action alert” urging Cook County residents to use less water to relieve pressure on sewers as more rain is forecast.

The water that goes down drains at homes and rainwater go to the same collection point. When too much water enters sewers too quickly, sewers can back up into streets and basements or overflow into the Chicago River.

The MWRD said the McCook Reservoir, which serves 3.1 million people from Wilmette on the north to Bedford Park on the Southwest Side, is approximately 91% full.

Thornton Reservoir, which handles the Far South Side and southern suburbs, is about 7% full; Majewski Reservoir, serving Arlington Heights, Des Plaines and Mount Prospect, is empty, the statement read.

Residents are asked to conserve water by delaying showers and baths, flushing less frequently and delaying running dishwashers or washing machines.

The flash flooding has also prompted calls for stronger response from officials.

On Monday, Southwest Side alderpersons wrote to Mayor Brandon Johnson seeking stronger mitigation efforts as heavy rain over the weekend left flooded streets and basements.

“Once more, thousands of families barely rebuilding from the first wave found themselves again flooded, in many cases worse than before, with no support or answers from City Hall as to how the City of Chicago was going to prevent this from being a recurring nightmare for so many Chicagoans,” the letter read.

The City Council members want city-funded “back flow” valves installed to minimize the damage of future flooding catastrophes. They estimate that residential unit installations could cost the city around $10,000 to $15,000 per building, and they urged the mayor’s office to use existing pools of water and sewer fund allocations.