Nearly 10 inches of rain falls on southern Wisconsin and metro Milwaukee, leading to flooding; more rain possible
A stubborn, slow-moving storm system dumped a month's worth — or more — of rain on the Milwaukee metro area and southeast Wisconsin on Sunday and early Monday, leading to flooding and wet basements across the region.
"Racine was hit the hardest," said Rebecca Hansen, a meteorologist at the National Weather Service in Sullivan. A weather observer in Racine near John Batten Airport recorded 9.76 inches of rain in the 24 hours ending at 5 a.m. Monday, Hansen said.
Some parts of Racine County likely tallied 10 inches of rain, Hansen added. Normal September precipitation at the Racine airport is 3.23 inches.
Flood warnings were in effect for the Fox River in Waukesha, the Root River in Franklin and Oak Creek in South Milwaukee.
A flood advisory remains in effect until 6 p.m. Monday for Milwaukee, Waukesha and Racine counties.
Flooded portion of I-94 reopens
Elsewhere, a portion of I-94 in Waukesha County was closed for a time on Monday because of high water.
As of 2:30 p.m., all lanes of the freeway had reopened, according to a statement from the Wisconsin Department of Transportation.
Earlier, westbound traffic on I-94 was being routed onto Wisconsin Highway 16 near Pewaukee to allow for water to be removed from the interstate.
Crews were pumping water from the eastbound lanes across the westbound lanes of I-94 to a drainage ditch. Westbound traffic was being routed onto Highway 16 and motorists were being asked to consider using Highway 83 or Highway 67 to reconnect with the westbound lanes of I-94.
The worst of the rain appears to be done, but drizzle and light rain were expected to continue at least through the morning hours on Monday, said Marcia Cronce, a meteorologist with the National Weather Service in Sullivan.
Things won't begin drying out until Tuesday. The rain and drizzle "will move out overnight, but not until then," Cronce said.
There is a 50% chance of light rain across the Milwaukee area and southern Wisconsin overnight Monday.
Light rain showers were located across central and southwest Wisconsin at midday on Monday. As the storm system was meandering eastward out over Lake Michigan, it was expected to drag more rain showers behind it on Monday night across southern Wisconsin, Cronce said.
Weather
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Racine received 9.76 inches of rain
Here are rainfall totals as of 9:30 a.m. for locations in southern Wisconsin, according to the weather service and the Milwaukee Metropolitan Sewerage District. The highest rainfall totals were in the southern part of the Milwaukee metro area, but rainfall totals varied widely depending on whether you happened to be located where a heavy rain band set up. Generally, the highest rainfall totals were in the southern portion of the Milwaukee metro area:
Racine: 9.76 inches
Wind Point: 7.75 inches
South Milwaukee: 7.55 inches
Waukesha: 7.48 inches
Wales: 7.3 inches
New Berlin: 7.2 inches
Oconomowoc: 7.1 inches
Greendale: 6.97 inches
Milwaukee (far northwest side) 6.62 inches
Menomonee Falls: 5.95 inches
Milwaukee Mitchell International: 5.57 inches
Milwaukee (Menomonee Valley) 5.23 inches
Germantown: 5.13 inches
Cedarburg: 4.19 inches
Saukville: 3.21 inches
The normal total rainfall for Milwaukee Mitchell International Airport for September is 3.16 inches.
Water overwhelms Milwaukee sewage system
The deluge led to a sewer overflow Sunday night and continued into Monday morning as rain continued to fall throughout the Milwaukee area.
The overflow started at 11:15 p.m. Sunday night and was ongoing as of 9 a.m. Monday, according to Bill Graffin, the Milwaukee Metro Sewerage District's public information manager.
The staggering rainfall totals prompted the Jones Island treatment facility to release water after reaching its capacity.
One inch of rain in the Milwaukee area equates to about 7.1 billion gallons of water. MMSD has the ability to allow overflows in order to prevent sewage backups into homes and businesses across the area. Overflows occur after the MMSD deep tunnel system reaches capacity during heavy rain and more water is flowing into treatment plants than can be processed.
Though there is a risk of untreated sewage being released into water bodies during overflow events, most of the water released — over 90% — is the rainwater flowing out of the system as soon as it rushes in.
This is the first overflow of the year for MMSD, one of six allowed yearly by the state Department of Natural Resources under the district's state discharge permit. In 2021 there were two overflows — one in August that released nearly 400 million gallons of water, and another in October that released about 10,000 gallons, according to MMSD.
As of 12:30 p.m. n Monday, the deep tunnel water storage system was at 90% capacity and the Jones Island water treatment plant was operating at capacity.
Milwaukee residents urged to reduce water usage
In a bid to lessen the amount of water being released into Milwaukee water bodies, MMSD issued a water drop alert Sunday night as well, asking residents to use less water in their homes. The department recommends saving laundry and dishes for another day, taking shorter showers and ensuring there is enough room in your rain barrel before heavy weather events.
Restoration companies swamped
Water damage restoration companies across southern Wisconsin reported being inundated with calls for water damage to homes.
At Paul Davis Restoration in Milwaukee the phones are ringing nonstop, a representative said. Extra staff are answering calls.
At Kelmann Restoration in Wauwatosa, "We're pretty darn busy," answering and responding to water damage calls, a representative said.
Weather system 'a nuisance to forecast'
The weather system that caused this is known as a "cutoff low" or a "closed low," Cronce said.
Such storms set up over an area and then they just stay put.
"These cutoff lows are a nuisance to forecast because their movement is not as predictable," Cronce said. "They drift (slowly). And they bring crummy weather."
Heading into Sunday, the Milwaukee area was 2.52 inches below normal for precipitation for the year. That helped soak up some of the rain, but eventually the soil was saturated and overwhelmed.
"We have been generally dry," Cronce said. "The ground could take a lot of water.
"If this was a wet year, we'd be looking at a lot worse conditions for flooding," she added.
Sunny skies are forecast for Tuesday, Wednesday, Thursday and during the day on Friday. Rain chances return on Friday night and continue into the weekend, the weather service said.
Contact Joe Taschler at (414) 224-2554 or jtaschler@gannett.com. Follow him on Twitter at @JoeTaschler or Facebook at facebook.com/joe.taschler.1.
Laura Schulte of the Journal Sentinel staff contributed to this report.
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This article originally appeared on Milwaukee Journal Sentinel: Milwaukee, Waukesha, Racine see 7 to 10 inches of rain