Dam breach in Manawa, Wisconsin leads to evacuations and flood damage
Image credit: NBC26 (stillshot)
A privately owned dam in Manawa, Wisconsin was breached on July 5, 2024, due to heavy rains that delivered about 127 mm (5 inches) of water, overwhelming the dam and causing a flash flood that prompted the evacuation of residents living down the river.
According to the National Weather Service’s report, the incident occurred at approximately 13:45 LT due to intense rainfall that caused floodwaters to overwhelm the dam along the Little Wolf River.
Meteorologist Scott Cultice confirmed that about 127 mm (5 inches) of rain fell in Manawa over several hours starting at 08:30 LT.
“It just wouldn’t stop raining in and around the Manawa area,” Cultice said. “They had water rescues. Most of the downtown roads were flooded.” The heavy rain and subsequent flooding led to a flash flood warning for Manawa and other parts of Waupaca County.
Manawa Police Chief Jason Severson estimated a 15 m (50 foot) wide area around the dam had eroded. “It looks like the dam is intact, but there is quite a bit of erosion on the north side,” Severson reported. “We think the worst of it is over, so now we’re going to start assessing things and see where we go from here.” As the situation worsened, authorities began evacuating some homes.
The city, with a population of about 1 200, experienced severe flooding that led to water rescues and significant road closures. “Due to the amount of water, the dam isn’t safe,” the Manawa Police Department posted on Facebook. All entrances to the city were blocked, and roads including Union Street, N. Bridge Street, Beech Street, Howard Street, and Industrial Drive were reported flooded or washed away.
Emergency shelters were set up at a high school and a Masonic center to accommodate evacuees. Christine Boissonnault, a resident who spent most of July 5 in the high school shelter, described the situation as shocking. “I cried when I came down and saw it. My daughter works at the store and she said she saw and heard the water going down the road,” Boissonnault told WFRV-TV.
A preliminary flash flood event summary by NWS said that a low-pressure system had tracked east across the region, bringing 100 to 150 mm (4 to 6 inches) of rain to Waupaca County and 25 to 102 mm (1 to 4 inches) to parts of Outagamie, Brown, Calumet, Kewaunee, and Manitowoc counties. The combination of this rain and previous rainfall over the past two weeks led to the dam’s failure.
The evacuation order was lifted by 17:00 on July 5 as floodwaters subsided. Severson confirmed that dozens of homes in the community were temporarily evacuated.
“There were no reports of injuries following Friday’s dam breach,” he stated. The main cleanup efforts involve residents dealing with flooded basements. “There’s a lot of homes that did take on water in their basements. The water was so high it was just running through the streets and some people took on property damage,” Severson explained.
Despite the lift on the evacuation order, the city’s wastewater treatment plant remained offline due to the flooding, and a boil-water advisory was issued for Manawa and surrounding areas. The high school and Masonic lodge emergency shelters were shut down Friday night as people returned home.
The Wisconsin Department of Transportation inspected and found the dam largely intact, except for the erosion on one side. The National Weather Service has warned that rain and possibly thunderstorms could continue through the weekend and into early next week.
References:
1 Preliminary Flash Flood Event Summary – NWS – July 5, 2024
2 Eastern Wisconsin community evacuated after floodwaters breach dam – AP– July 6, 2024
3 Residents in Wisconsin community return home after dam breach leads to evacuations – AP– July 6, 2024
I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.
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