Chicago River

Chicago officials reverse flow of river into Lake Michigan to ease flooding from heavy rain

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Officials with the Metropolitan Water Reclamation District of Greater Chicago announced Sunday that they have allowed water from the Chicago River to go into Lake Michigan to help alleviate shoreline flooding after heavy rains pounded the area.

According to a press release, up to four inches of rain have been recorded in some locations over the last two days, leading to the decision to reverse the river’s flow at the Wilmette Pumping Station.

This decision comes after the National Weather Service issued a flood warning for the North Branch of the Chicago River, urging residents to use caution in coming days as water levels rise.

“There are several factors we consider when determine to release floodwater to the lake, including the rate the river water level is rising at each lakefront control location,” officials said. “(We also consider) if the rainfall intensity is continuing or beginning to decrease.”

Nearly all of Chicago’s beaches have now closed because of “poor water quality conditions,” according to the Chicago Park District. It is unclear whether water will be safe enough to allow for swimming for the Fourth of July holiday.

Water quality conditions are updated daily at 1:30 p.m.

Releases of floodwater into Lake Michigan are exceedingly rare, with the last one occurring in 2020. Engineers reversed the flow of the river in the early 1900’s to both allow drinking water to enter Chicago and surrounding suburbs from the lake, but more importantly to prevent sewage and pollutants to enter one of the world’s largest freshwater lakes.

During times of persistent heavy rainfall, that reversal is halted, allowing water to enter the lake to help lower river levels. Sewage can be included in that water, which can lead to water quality issues for short periods of time along the lake.

Footage from Telemundo Chicago’s Jorge Desantiago showed that the Chicago River was overflowing its banks along the downtown riverwalk because of the heavy rains on Sunday, with more than three inches falling at Midway International Airport and even higher totals reported in other parts of the city.

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