Photo: Iulus Ascanius at English Wikipedia · Public domainFEMA expects about as much hazard damage per building in Oconomowoc as in the typical U.S. town, mostly from river and rain flooding
On FEMA’s National Risk Index, Oconomowoc gets a C+ for hazard risk: higher expected damage per building than 60% of U.S. towns, #327 of 362 in Wisconsin. Most of that expected damage is river and rain flooding (87%). Flood insurance has paid 2 claims here since 1982.
Graded on FEMA’s expected yearly building damage per dollar of building value (NRI v1.20, December 2025), weighted by where residents live; flood claims are shown, not graded. How hazard risk is graded
What Oconomowoc faces
Each hazard’s share of the building damage FEMA expects here, and how its rate compares with the rest of the country.
River and rain flooding
Tornadoes
Shares are of FEMA’s expected building damage, the measure the grade uses; ranks compare each hazard’s building-damage rate with all 85,154 U.S. census tracts. In FEMA’s terms, river and rain flooding is FEMA’s “Inland Flooding” (rivers and streams overflowing their banks, or rain overwhelming drainage). FEMA defines coastal flooding as high or rising tides and storm surge, so surge damage is counted there. Drought isn’t listed: FEMA counts its losses in crops only.
What’s behind Oconomowoc’s grade
River and rain flooding is 87% of the building damage FEMA expects in Oconomowoc, and Oconomowoc’s rate of river and rain flooding damage is higher than 77% of U.S. census tracts. Next is tornadoes at 8% (higher than 73% of U.S. census tracts).
C+ #327 of 362 in Wisconsin; higher expected damage per building than 60% of U.S. towns (21,298).
Oconomowoc’s residents live in 6 census tracts; FEMA’s figures are combined by where they live.
The typical Wisconsin town has lower expected damage than 79% of U.S. towns; within the state, Oconomowoc has more expected damage per building than 90% of Wisconsin towns.
In dollars, FEMA expects about $8.2M a year in losses across Oconomowoc: $5.8M to buildings, the rest to people and crops.
Does Oconomowoc flood? Rarely: 2 flood claims since 1982
Every paid claim on a federal flood insurance policy in Oconomowoc, from FEMA’s records: 0.2 per 1,000 homes, fewer than 96% of the 13,809 U.S. towns with a flood insurance record.
Oconomowoc isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Waukesha County.6 federal disasters brought FEMA money to Oconomowoc
Disasters that paid out in Oconomowoc itself (aid to households or repair grants to the City of Oconomowoc), newest first, with that year’s flood claims.
- 2026Severe Storms, Tornadoes, and Flooding6 households applied for aid$6K aid approved
- 2025Severe Storms, Straight-line Winds, Flooding, and Mudslides16 households applied for aid$100K aid approved
- 2008Severe Storms, Tornadoes, and Flooding330 households applied for aid$1.1M aid approved$12K to the City of Oconomowoc for repairs
- 2008Record Snow and Near Record Snow$31K to the City of Oconomowoc for repairs
- 2004Severe Storms and Flooding1 households applied for aid$276 aid approved
- 2000Snow$10K to the City of Oconomowoc for repairs
Waukesha County has had 16 natural disasters declared by the President since 1953, most often floods, then severe storms. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Old photos of Oconomowoc after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Oconomowoc archive →Oconomowoc and its neighbors
Oconomowoc is 4th of the 4 graded towns here, from least expected damage per building to most. Tap a town to see its hazards.
| Town | Hazard risk | Mostly (buildings) | Flood claims |
|---|---|---|---|
| Concord | B+less damage than 67% | river and rain flooding | 1 |
| Summit | B+less damage than 65% | river and rain flooding | 4 |
| Oconomowoc | B−less damage than 50% | river and rain flooding | 1 |
| Oconomowoc | C+more damage than 60% | river and rain flooding | 2 |
| Oconomowoc Lake | — | 669 residents; we grade 1,000+ | |
| Okauchee Lake | — | a Census area inside a town; graded with the town | |
Hazard risk = FEMA’s expected yearly building damage per dollar of building value, vs. the 21,298 U.S. towns we grade; the map is shaded by fifths of the same scale. Flood claims = paid federal flood insurance claims on record.
Get ready for what Oconomowoc faces
A short kit for the hazards that drive the building damage here, what to check before you buy, and where neighbors get alerts.
- Turn around at flooded roads: a foot of moving water can carry off a car.
- Flood insurance usually takes 30 days to start, so buy it before the forecast.
- Keep papers and medicines up high, in a grab-and-go bag.
- Pick your spot now: the lowest floor, an inside room, no windows.
- A watch means be ready; a warning means take cover now.
- Keep shoes and a flashlight by the bed.
- Look up the address on FEMA’s flood map.
- Ask the seller or landlord whether it has ever flooded, and what flood insurance costs there.
- Get a flood insurance quote early: policies usually start 30 days after you buy.
Know where neighbors sign up for alerts? Add it to the Handbook so everyone has it.
Questions about natural hazards in Oconomowoc
Is Oconomowoc at risk for natural disasters?
On FEMA’s National Risk Index, Oconomowoc has higher expected damage per building than 60% of U.S. towns: C+ for hazard risk, #327 of 362 in Wisconsin. Most of the expected damage is river and rain flooding (87%) and tornadoes (8%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Oconomowoc flood?
Flood insurance has paid 2 claims in Oconomowoc since 1982, $3K in all, or 0.2 per 1,000 homes, fewer than 96% of U.S. towns with a flood insurance record.
Is Oconomowoc in a flood zone?
Flood zones are drawn street by street, so the answer depends on the address: look it up on FEMA’s flood map. In Waukesha County, 66% of homes in mapped flood zones carry federal flood insurance, and 0.6% of all homes do.
How much is flood insurance in Oconomowoc?
FEMA’s Community Rating System list shows no discount for Oconomowoc’s flood program. Premiums depend on the building; policies usually start 30 days after you buy, so get a quote early.
What was the biggest storm in Oconomowoc?
By FEMA money that reached Oconomowoc, Severe Storms, Tornadoes, and Flooding (2008): 330 households applied for aid, $1.1M approved, and $12K to the City of Oconomowoc for repairs.
Is Oconomowoc at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (87%), and Oconomowoc’s rate for it is higher than 77% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Oconomowoc.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Oconomowoc’s residents lived in the 2020 census; OpenFEMA: NFIP redacted claims, multiple-loss properties, community status book and residential penetration rates, housing assistance (owners and renters), public assistance funded projects, hazard mitigation properties and disaster declarations. Homes: Census ACS 2020–24. Preparedness tips: Ready.gov. FEMA’s model is an average of expected damage, not a forecast. How hazard risk is graded.