This post summarizes a new Wisconsin Policy Forum report showing that climate change is driving a sharp rise in flood damage and insurance claims across the state, with southern Wisconsin hit hardest.
It places the report’s findings in context — from a devastating Aug. 9–10 “1,000-year flood” in southeastern Wisconsin to long-term trends in losses, insurance costs, and the policy choices communities face to reduce future harm.
Key findings from the Wisconsin Policy Forum report
The report links increasing flood losses to heavier rainfall and more frequent extreme events, projecting that these trends will continue over the next two decades.
It highlights both historic storms that produced large losses and the growing financial strain on homeowners, insurers, and local governments.
Damage trends and notable storms
Floods are the state’s second-most frequent disaster, and the report cites $123.7 million in flood damages since 1999.
There have been major spikes in specific years including 1997, 1998, 2008, 2010, and 2018.
That catalog of events underscores that flood risk has been persistent and is intensifying.
Notable incidents include the 2008 record rainfall that dropped 12 inches in two days and caused about $49 million in damages.
The 2018 floods in Dane and Sauk counties accounted for roughly $24 million.
The Aug. 9–10 southeastern Wisconsin event, described as a “1,000-year flood”, is expected to produce one of the state’s highest-ever insurance claim totals.
Why southern Wisconsin is especially vulnerable
Flood damage is not evenly distributed across Wisconsin.
The southern portion of the state experiences larger losses because of physical geography and human factors that concentrate exposure and vulnerability.
Topography, population, and property values
The report emphasizes three drivers of concentrated risk:
Milwaukee leads the state in recorded flood losses, with about $25 million in damages since 1978.
This illustrates how urban centers can accumulate large financial impacts even if annual events are localized.
Insurance, infrastructure, and policy choices
As flood risk increases, the economic consequences for homeowners and municipalities grow.
The report provides useful metrics on insurance and identifies strategies that reduce long-term cost and risk.
Insurance costs and mitigation progress
As of 2023, the median annual flood insurance premium for a single-family home in Wisconsin is about $804, slightly above the national average.
Premiums often do not fully reflect future climate-driven risk, exposing homeowners and taxpayers to potential shortfalls.
Milwaukee has made measurable progress with green infrastructure and stormwater improvements.
Rain gardens, permeable pavements, and upgraded conveyance systems reduce runoff, lower peak flows, and help limit damage during heavy precipitation events.
Policy trade-offs: development controls vs. housing affordability
The report urges stronger local development controls to limit runoff and reduce flood exposure.
From my three decades in the field, I recognize these tools — setbacks, open-space requirements, stormwater ordinances — are effective but politically and economically sensitive.
Restricting development or imposing higher mitigation standards can raise housing costs or slow new construction.
Policymakers must balance the immediate need for affordable housing with long-term resilience to extreme weather events.
Practical next steps include prioritizing green infrastructure investments and updating local zoning and stormwater standards.
Aligning insurance signals with true flood risk is also important.
Here is the source article for this story: Wisconsin piling up costs from more floods, report finds. And that was before this deluge.