Milwaukee Experiences 1,000-Year Rain Event
Record rainfall pounded city Saturday into Sunday.
A boat and pier float down the Milwaukee River. Photo by Jonathan Ward.
Milwaukee area residents experienced record-setting rain and 1,000-year flood over the weekend. They also saw four area rivers climb to record levels.
The city and its suburbs were besieged with a two-day rain event, where a series of storms dumped nearly 15 inches of rain in certain neighborhoods. Before the deluge, the city had only experienced 20 inches of rain total in 2025, a figure in line with historical averages.
But nothing about what happened last weekend was average.
The event was classified as a 1,000-year rainfall event.
According to National Weather Service data going back to 1871, only one time has Milwaukee seen that much rain in such a short period: 2008.
But that doesn’t exactly mean that Milwaukee residents have experienced two once-in-a-millennia events in 17 years.
The 1,000-year designation is actually a measure of probability. That volume of rain has a one in 1,000 chance of happening in a given year.
To reach the designation, Milwaukee needs to receive 8.98 inches of rain over 24 hours. A probability table, based on historical data, determines the designations.
The official city total, tracked at Milwaukee Mitchell International Airport, was 5.74 inches of rain on Saturday, Aug. 9 and 1.17 inches on Sunday, Aug. 10 for 6.91 inches. But the airport is located in the southeast corner of the city, an area that was spared from the first round of showers Saturday. Even so, Saturday was the second wettest single day since 1871, according to the Wisconsin State Climatology Office.
On the northwest side, James Madison High School, 8135 W. Florist Ave., recorded 14.69 inches according to a Milwaukee Metropolitan Sewerage District tracker.
Based on National Weather Service, Pewaukee led the way regionally, with 12.61 inches over the weekend. Northwest side suburbs Butler and Menomonee Falls recorded 12.22 inches and 12.06 inches.
The 24-hour official city count in June 2008 was 7.18 inches. The record one-calendar-day, city total is 6.81 inches in 1986.
Basements Flooded, Water Everywhere
“I certainly hope that a storm like this is not upon the city for at least another millennium,” said Mayor Cavalier Johnson at a press conference Monday morning.
While he spoke at the South Drop-Off Center, dozens of vehicles were lined up to drop off debris. The city opened its two drop off centers on Monday, a day they are normally closed, to attempt to aid residents in cleaning up. It’s also announced a special bulky item pick up. See more details about the cleanup in our companion article.
“What really kind of overwhelmed our systems is when you get three inches of rain in one hour,” said Department of Public Works Commissioner Jerrel Kruschke. “And there’s not any system in the country that can handle that.”
The staggering amount of water made itself visible virtually any way it could.
The MMSD Deep Tunnel for the combined sewer system quickly filled with nearly 500 million gallons and then an overflow had to be called, sending sewer water directly into area rivers and Lake Michigan. The overflow, still active as of publication, was its first in 2025.
The Milwaukee, Kinnickinnic, Menomonee and Root rivers all recorded highs, with the Milwaukee River eclipsing its flood level by more than four feet and seeing many boats and piers break away and float downstream.
Several area bridges were briefly submerged, with the Canadian Pacific Kansas City railroad bridge over the Menomonee River in the Wauwatosa Village becoming a social media icon as water and debris pounded it. Nearby Hart and Hoyt parks also experienced substantial flooding.
In the city proper, many areas experienced flooding including the Menomonee Valley, Brewers Boulevard near American Family Field and countless streets and intersections.
For more than a decade, MMSD has been systematically funding green infrastructure projects to expand stormwater retention capacity beyond just the Deep Tunnel system.
Based on photos posted to social media, Pulaski Park, built on a bend in the Kinnickinnic River, retained a substantial amount of water that would have otherwise made water levels even higher. Just downstream, debris and stalled vehicles could be spotted along W. Harrison Avenue. Where the street is closest the river, MMSD has deconstructed all of the homes in the past 10 years. Had it not, those homes would have otherwise been devastatingly flooded, though a bigger project awaits to naturalize the concrete-channeled river and further reduce flooding. A rebuilt berm and wall along the Menomonee River in the Miller Valley avoided devastating flooding.
Several Milwaukee Public Schools properties have received MMSD grants to reduce the amount of pavement and new buildings receive grants to build green roofs, cisterns and other retention features. City street projects can include bioswales, which act as temporary ponds and reduce reckless driving by narrowing the roadway.
“Just imagine how this would have turned out if we hadn’t done that work over the past number of years,” said Johnson. “I mean, who knows how many hundreds or thousands or perhaps millions of gallons of storm water that we were able to capture that didn’t end up in the streets.”
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