ROBERTS, Wis. — The Roberts Waste Water Treatment Plant could be inundated with water by 2026 if the level of Twin Lakes continues to rise unabated, according to a recent study.
The analysis by engineering firm SEH for Warren Township details a long-term flooding problem that also threatens homes and roadways around the pair of seepage lakes southwest of Roberts. It also offers a range of potential — though likely unpopular — solutions.
“Unfortunately you’ll find that our report doesn’t have a silver bullet to your solution,” said Brad Woznak, lead engineer of the study, at a meeting Oct. 5 of the Twin Lakes Joint Committee with representatives from the village of Roberts and town of Warren.
The most feasible mitigation strategy is pumping water from Twin Lakes into the Kinnickinnic River system, but Woznak cautioned that discharging into the prized trout stream would face public backlash and a “permitting nightmare” with the Wisconsin Department of Natural Resources.
“I think you’re all aware of what an outstanding resource that river is, so being able to pump there brings a whole other set of obstacles,” Woznak said to committee members.
Though water could be used to irrigate nearby crops, the vagaries of summer dry spells could also mean a drastic decrease in the water level, according to the report.
The Roberts Waste Water Treatment Plant contributes to Twin Lakes flooding, with daily discharge accounting for around 12% of total inflow during summer 2019, the report states. Reducing inflow from the plant by half would stem the tide of rising water but not significantly lower lake levels.
The plant has been discharging into Twin Lakes since being constructed in the 1960s. Other contributing water sources during the 2019 study period were:
- 71% from precipitation
- 17% from rainfall runoff
Water levels on Twin Lakes have increased 5.8 feet over the past 12 years, or about 6 inches per year, according to the study. The surface elevation was just over 970 feet in August — enough to inundate 112th Street. If water continues to rise at a similar rate, 107th Street will be inundated within the next two years.
Public comment at the committee meeting was occasionally heated, with some residents voicing frustration over years of study and discussion while houses are being damaged by flooding. The DNR also was criticized for not being present.
The DNR has suggested a no-pumping alternative with the potential for acquiring at-risk properties and elevating critical infrastructure, which could be cheaper and pose the least amount of environmental disruption. Dan Funk, a concerned citizen and member of the non-profit community association Friends of the Twin Lakes, said the group plans to ask the DNR for the analysis behind that conclusion.
“A key factor that appears to be missing is the recreational value of restoring Twin Lakes to the significant recreational asset to the community that it was prior to 1962,” Funk wrote in an email to the Star-Observer on Wednesday, adding that restoring the lakes would boost surrounding property values.
The group’s goal is to first stop waste water discharge from Roberts and then bring down the water level on Twin Lakes.
The $12,000 SEH study was funded in part through a Large Lake Planning Grant. The next step, Funk said, is requesting the village of Roberts to apply for another grant to write an application to the DNR for an alternative discharge site.
The group presented the request to the Village Board in September. Now that the SEH report is out, Funk said they will bring the request again at the Monday, Oct. 12, meeting.
This story was updated Oct. 9, 2020, with additional details from the engineering study.