By Tom Fehring
“It was like someone pulled the plug on the bathtub drain!
All of sudden the water level began to drop!”
Village resident, discussing the 2010 flooding in Whitefish Bay
“Some believe the level of backups in their basements dropped rapidly because someone opened a gate or pushed a button. There is no gate, no button. Our hypothesis is that as the water receded, it created capacity in the sewers for the flow out from the basements."
WFB Village Manager James Grassman,
Speaking with residents regarding the 2010 flooding incidents
On July 15, 2010, almost 6 inches of rain dropped on Whitefish Bay over a twelve hour period. Seven days later, with the ground still saturated, an amazing 7.5 inches fell in a four hour period. It was reported that both of these rain events exceeded ‘100-year storm’ events, meaning they had a probability of occurring only once in a century or so.
The results in the Village were dramatic. In some areas, city streets turned into rivers. Basement flooding was wide-spread. The cost of damage to homes and businesses in Whitefish Bay was estimated at over $10 million, and was more than experienced in any other community in Milwaukee Country including the City itself.
The above view from the Wilshire neighborhood is an example of the street flooding that was experienced during the July 2010 storms.
Local news coverage was extensive. Curiously, some Village residents reported that during the course of the storm the rising water levels began to quickly recede – even while it was continuing to rain. One resident reported, “It was like someone pulled the plug on the bathtub drain! All of sudden the water level began to drop!”
Such claims were quickly dismissed by Village officials. They noted that, “There is no gate, no button” that could be opened to cause a reduction in the water levels.” Still, the reported observations seemed mysterious.
A week or so following the storms, I happened to be walking down to the bluff at Big Bay Park and noticed the safety gate that had covered the storm water discharge line had been ripped from its mooring.
I took a few pictures. The adjacent picture shows the condition of the safety gate, still partially cluttered with debris, including some construction debris from the nearby Fairmount Avenue project. I also noted that the bolts that formerly held the gate in place had failed – they had literally popped because of excessive force.
It is evident that the safety gate became partially plugged with debris during the storm (including construction pipe segments and who knows what else), which impeded the flow and caused the storm water mains to back up. The force of the water ultimately ripped the gate from its connections, which then allowed the backed up water to continue its rush to the lake.
In my mind, this is the likely explanation regarding reports that the water levels fell quickly mid-way through the storm.
This could also explain part of the reason for the significant back-ups in the storm water system experienced during the July 2010 storms in the Cramer/Wilshire and Palisades neighborhoods, as well as the far-eastern portion of Fairmount Avenue.
It is important to note that the outfall did not have to be completely plugged in order to contribute to a significant back-up of this portion of the storm water sewer system. Even a partial plugged outfall would have reduced flow substantially. As an analogy, a partial blockage of a sink drain will cause water to back-up in the sink because the drain can no longer keep up with the flow.
When I related this to the Village’s engineering staff, they were not convinced. However, they eventually had their consultant review the situation. Donahue and Associate concluded that the partially blocked safety gate likely contributed to the surface flooding.
A week or so later, I happened to be walking across the Milwaukee River on Silver Spring Drive and noticed that the storm water outfall at that location (on the east bank of the river) was similarly plugged – and that the resulting force caused the culvert to be separated from the line. See the adjacent picture.
It appears likely that this plugged outfall also caused storm water to back up in the neighborhoods that it served.
The good news is that both of these storm water discharges have been redesigned. The revised safety gate protecting the outfall at Big Bay Park is now unlikely to become plugged.
Since the July 2010 storms, the Village of Whitefish Bay has spent millions to improve its infrastructure –to provide additional stormwater capacity to deal with extreme rainfall events and to reduce the leakage into the sanitary sewer system. Retention basins have also been installed, to include the one at the recently redesigned Cahill Square, and adjacent to Cumberland School. Whitefish Bay High School has also installed a substantial retention system under its parking lot. Hopefully these and planned upgrades will reduce the impact of future extreme storm events.
Above: Shortly after the July 2010 storms, some Whitefish Bay streets were lined with damaged debris. The cost of the damage from these storms in Whitefish Bay was estimated at over $10 million.
Your link to the biggest stories in the suburbs delivered Thursday mornings.
Enter your e-mail address above and click "Sign Up Now!" to begin receiving your e-mail newsletter Get the Newsletter!
- North Shore Police Reports: September 18, 2014
- North Shore Police Reports: September 11, 2014
- St. Monica to host car wash
- North Shore Police Reports: September 4, 2014
- North Shore Police Reports: August 28, 2014
- With state funding tied to enrollment, North Shore public schools turn to marketing
- Whitefish Bay leads state in ACT scores
- Tennis courts receive another $60K in district funding
- North Shore Police Reports: August 21, 2014
- Voter turnout high in North Shore