The waters of the Mill Pond dam in Manawa flooded around the structure holding it back Friday following heavy rain. The onrushing water flooded streets and forced dozens of homes to be evacuated. Here’s what we know one day after the flooding.
Did the Manawa dam fail?
No, the dam itself didn’t fail. Rather, the earth on the sides of the dam became eroded enough to give way to the waters behind the dam, according to Manawa Mayor Mike Frazier.
Why did the flooding occur in Manawa?
Flooding in Manawa started after the area received heavy rain. The pressure of the water behind the dam couldn’t be contained by the eroded embankment, city officials said.
How much rain did the area receive?
Since Friday morning until Friday afternoon, Manawa received 5.6 inches of rain, according to NWS of Green Bay Meteorologist Kurt Kotenderg.
Where is Manawa?
Manawa is located in central Waupaca County. It has a population of 1,238, according to its Census Reporter page.
How many homes and buildings needed to be evacuated?
Mayor Frazier said that around 100 residences were evacuated.
However, that number does not include the number of people who were evacuated outside of the city limits. Frazier said the city does not know what that figure is.
As of 5 p.m. on Friday, all evacuated residents, apart from those living in the nursing home, were able to return to their homes, according to Manawa Police Chief Jason Severson.
Frazier estimated 160 firefighters from Manawa and surrounding municipalities were on stand-by Friday in the event that more evacuations were necessary.
Can people go into the floodwaters?
Officials advised people to not wade or drive in flooded areas. The city said if someone has been in the flooded areas, they should wash with soap and clean water, as well as making sure they are up to date on their tetanus vaccinations.
How much will it cost to clean up the area?
Frazier said the city has received an initial estimate of $5 million to repair roads and other damages done to city property by floodwaters.
In addition to the roads, repairs are needed to the dam and its embankment, Severson said.
The wastewater treatment plant also needs to be cleaned up and restart operations. Residents are advised by the city to either boil their tap water for consumption or use bottled water until the plant is running and there have been tests done to ensure a drinkable quality of water.
“I couldn’t even guess how long it would take for any of those projects,” Severson said.
Has flooding like this happened before in Manawa?
There was a close call for the dam to start flooding in 1969, according to Frazier. Since then, the city has not had anything like this happen until this year, he said.
When was the dam built?
The dam’s construction was completed in 1920, according to Manawa’s official city website.
When was the last inspection of the Manawa dam?
The Wisconsin Department of Natural Resources’ repository of dams listed the dam’s last inspection date as February 28, 2015.
What about the closed roads?
Roads that were closed due to flooding in Manawa reopened Friday evening. These roads included Union Street, Beech Street, Howard Street, Industrial Drive and Highway 22.
Did Manawa’s mayor have any additional information?
Frazier said that he was told by emergency responders that the erosion that gave way to water being released “saved the dam” from the tremendous pressure acting on it that might have caused a more severe scenario.
“Most of the water is gone except for the flooding in Lindsay Park,” said Frazier. “(The city) has repaired our streets temporarily.”
Rashad Alexander, Hannah Kirby and James B. Nelson contributed to this report.
This article originally appeared on Milwaukee Journal Sentinel: What we know about the flooding in Manawa in Waupaca County
