Posted on August 17, 2022
Sheboygan has spent millions of dollars to prevent a disaster as devastating as the flood of 1998.
But with Lake Michigan water levels expected to rise and continue to undergo extreme fluctuations, the City of Sheboygan and a regional research group are preparing additional planning and projects to address a future with more flooding and erosion. These combined efforts include conducting a two-year project to assess flood disaster preparation as well as spending millions more on a shoreline restoration project.
Preparing for flood disasters
Lake Michigan’s average water levels rose 6 feet between January 2013 and November 2019, and nearly 2 feet between January and July 2019, according to the National Weather Service.
The lake reached a record high levels in 2020 before falling about 3 feet over the last two years, according to data from the U.S. Army Corps of Engineers.
Water levels are expected to continue fluctuating, reaching higher highs as well as lower lows in the future because Lake Michigan and the climate have become more volatile, said Jackson Parr, University of Wisconsin Sea Grant Institute staff member.
Through the Wisconsin Sea Grant, Parr is working with staff at the Bay-Lake Regional Planning Commission and Wisconsin Emergency Management to examine flood preparedness of nine northeastern Wisconsin cities on Lake Michigan’s shore, including Sheboygan.
The project will consist of three components: an independent flood vulnerability assessment, an extreme-event simulation and a resiliency scorecard.
The vulnerability assessment will pinpoint areas in Sheboygan that are most susceptible to flooding.
One of the research goals is to understand the interaction between rising river levels and rising water levels in Lake Michigan, Parr said, because many shoreline cities have rivers running through them, making them more likely to flood.
The extreme-event simulation, which will be focused on next summer, is a disaster scenario created by the National Academy of Sciences that will bring together local officials and emergency services in Sheboygan and present them with a flood event based on the vulnerability assessment.
“We’ll run that (information) through this simulation, which really just provides a way for local officials to practice their response and identify maybe some gaps in preparedness or communication holes that can be covered,” Parr said. “The best experience is when an event happens, but we’d like for communities to be able to practice their response without devastating flooding occurring.”
The research group also is considering ways to get more residents involved.
The third component, the Plan Integration for Resilience Scorecard, will assess the plans Sheboygan already has in place for floodplain management and flood disasters.
The city of Sheboygan shares several flood resources for residents, including tips for living on the lakeshore and an interactive FEMA map to determine floodplains in the area.
One reason the research group is focusing on northeast Wisconsin cities, such as Kewaunee, Algoma and Sheboygan, is because many resources already are being dedicated to cities along the southeast shoreline.
“We kind of wanted to shift our focus to communities that maybe don’t get as much attention,” Parr said.
Sheboygan retrofitted its storm system after the flood of ‘98
Sheboygan has experience with severe flooding.
In August 1998, torrential storms brought 10 inches of rain within a 24-hour period.
“(It) just kept raining,” David Biebel, director of public works, said. “It was like a downpour that you get like for a half hour, but it was like that for hours and hours. It just didn’t stop raining … and the system couldn’t handle it. Streets started backing up. Then it started flowing overland wherever low areas were.”
Over 800 homes had water damage, and 16 houses on Camelot Boulevard had to be torn down because they were too damaged to fix.
Back then, Biebel said, design standards for storm water management only accounted for a 10- to 25-year storm event.
Sheboygan began retrofitting its storm sewer system to handle a 50- to 100-year storm after the flood of 1998. Biebel estimates the work cost over $25 million. The redesign addressed low-lying areas, drainage systems and overland relief paths.
Design standards for flood infrastructure have changed, and other control methods like detention ponds are being used in newly developed areas to help capture runoff.
Biebel said Sheboygan is in a much better place today because of the infrastructure upgrades. If the storm sewer system hadn’t been updated, large rain events in prior years could have caused more property damage, he said.
“There’s been periods where, yes, we’ll have what we call ‘nuisance flooding’ in our world, where it will back up in the street,” Biebel said. “The street will flood. It might even get up above the sidewalks. But it doesn’t get to the properties.”
Those “nuisance” events include flooding that resulted in more than 20 road closures in spring 2019 and torrential storms that brought 5 inches of rain to the county in summer 2020.
Ryan Sazama, city engineer, said homes would have been hit again by recent flooding events if the storm sewer systems in areas like the south side hadn’t been retrofitted.
Sheboygan is working to address shoreline erosion
In all his life in Sheboygan, Biebel said he hasn’t seen the lake’s water levels fluctuate as tremendously as they have in the past few years.
“It’s always been a much more gradual up,” Biebel said. “It goes in swings and that’s just been the natural kind of flow of the lake levels. But I have never seen it swing so dramatically where it was, you know, up 4 feet above the (normal) height — almost to record levels — and now it’s already dropped that fast.”
Lake Michigan reached a record low of 576 feet above sea level in 2013, and has fluctuated since then, according to the U.S. Army Corps of Engineers.
This July, Lake Michigan’s water levels were 8 inches below levels the same time last year.
Anticipating future fluctuations in lake levels, the Sheboygan Department of Public Works partnered with the Wisconsin Coastal Management Program and Foth Infrastructure & Environment to study Sheboygan’s shoreline.
The results, presented at a public meeting in July, outline a restoration project along the 7 miles of shoreline in Sheboygan that would cost an estimated $31.5 million to $47 million.
“It’s expensive, we understand that. But it’s going to have long-term benefits,” Biebel said. “It’s important.”
Among the top priorities for the department are the Lake View Park site, the north bluff area, King Park Beach and the Blue Harbor shoreline, many of which have a high potential for property loss.
The Lake View Park site is a very urgent project and is in final design, Biebel said.
A sanitary sewer pipe that conveys 50% of the city’s sewage runs along the Lake View Park beach to the sewage treatment plant. With higher lake levels, the pipe is more vulnerable to crashing waves.
“We were really afraid that that pipe could fail, and it would start leaking raw sewage into Lake Michigan. So, we really looked at that site. That was our top priority,” he said.
Residents who live on the bluffs, where the shoreline rises and becomes especially steep, are concerned about erosion near the edges of their property.
“It’s a fine balancing act because you want to live on the coast, and you want beautiful views of the water. So, what do you do? You start mowing stuff and opening views up and cutting trees down so you can see,” Biebel said.
Fewer trees and vegetation can lead to more erosion because there is less soil stability.
Entire chunks of the land are sloughing off the hill, and groundwater is seeping out of parts of the hillside into Lake Michigan.
Solutions include installing drainpipes, adding more large stones along the slopes and planting vegetation with deep roots, which Biebel said will help stabilize the rocks and soil.
More erosion also could jeopardize a sanitary-sewer pump station that was built below the bluffs in the early 1900s.
A hundred years ago when much of the infrastructure was built along the shoreline, rain was able to soak into farmland in Sheboygan, rather than run off into Lake Michigan from “impervious areas,” like buildings and parking lots.
“We all benefited from it (the shoreline infrastructure), and we’re just in the position now that we realize if we don’t restore or add to it or protect it further, for the next 100 years, we’re not doing our jobs and we’re not really being as forward thinking as maybe some of our predecessors were,” Biebel said.
“You don’t want to piecemeal,” Sazama said. “You want to think — this design we’re talking about — you do this, you’re gonna be set forever.”
The Department of Public Works is seeking funding from a variety of sources, such as the Federal Emergency Management Agency, Wisconsin Economic Development Corp. and U.S. Department of Urban Housing and Development.