Natural hazards · Ottawa

Ottawa, WI natural hazards

Most of the natural-hazard damage FEMA expects in Ottawa comes from inland flooding, and overall the risk is low for a U.S. community. Flood insurance has paid 2 claims here since 2008. 3 federal disasters brought FEMA money into town.

FEMA National Risk Index, December 2025 · OpenFEMA claims, aid & declarations

Expected damage

How exposed is Ottawa?

Low

vs. U.S. communities

FEMA expects yearly storm and flood damage to homes and buildings in Ottawa to be higher than in 33% of U.S. communities, mostly from inland flooding and cold waves.

Inland flooding57%Cold waves17%Tornadoes16%Everything else11%

By hazard

What Ottawa faces

Each hazard’s share of the damage FEMA expects here, and how that compares with the rest of the country.

Inland flooding

57% of expected damage

Above average · higher than 52% of U.S. places

Recorded about 2 times a year in the area

Cold waves

17% of expected damage

Below average · higher than 33% of U.S. places

Recorded about 5 times a year in the area

Tornadoes

16% of expected damage

Above average · higher than 74% of U.S. places

Recorded about once every 65 years in the area

Lower here

HurricanesHailIce stormsWinter weatherHeat wavesWildfireEarthquakesLandslidesStrong windLightningDrought

Not a risk here

Coastal floodingAvalanchesTsunamisVolcanic activity

Flood risk changes street by street. Check a specific address on FEMA’s flood map, and ask about flood insurance before you buy.

Flood insurance claims

Does Ottawa flood?

Every paid claim on a federal flood insurance policy in Ottawa, from FEMA’s records.

2paid claims since 2008

$14Kpaid to owners

0homes flooded more than once

20082026

Biggest named events

Storm: 1 claim, $2K

of homes in flood zones
are insured

of all homes
are insured

No community discount. Ottawa 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.

Disasters that hit Ottawa

3 federal disasters brought FEMA money here

Disasters the President declared that paid out in Ottawa itself: aid to households, or repair grants to the Town of Ottawa.

Brought FEMA money into OttawaDeclared for Waukesha County only

2008

Severe Storms, Tornadoes, and Flooding

$11K to the Town of Ottawa for repairs

2008

Record Snow and Near Record Snow

$16K to the Town of Ottawa for repairs

2000

Snow

$12K to the Town of Ottawa for repairs

Waukesha County has had 17 natural disasters declared since 1953, most often floods and severe storms.

Around Ottawa

Ottawa and the towns around it

Very lowLowModerateHighVery high

Dousmanmostly inland floodingModerate

Summitmostly inland floodingLow

Ottawamostly inland floodingLow

Sullivanmostly inland floodingLow

Eaglemostly inland floodingLow

North Prairiemostly inland floodingLow

Geneseemostly inland floodingLow

About these numbers

How to read this page

An average, not a forecastFEMA’s National Risk Index estimates the damage 18 kinds of natural hazards cause in a typical year, from decades of records and models. A quiet decade can follow a bad year.

Compared by rate“Higher than N%” compares yearly damage as a share of what’s here, so a big city isn’t rated riskier just for having more buildings. Ottawa covers 2 census tracts, combined by population.

Money that reached townFlood claims are matched to Ottawa’s own flood-insurance community (here, the census tracts inside it); household aid to the registrant’s city; repair grants to the Town of Ottawa. FEMA’s model follows property values, so a place that recently lost many homes can rate lower than it feels.

FEMA’s expected losses across Ottawa total about $3.7M a year, counting buildings, people and crops.

Sources: FEMA National Risk Index (December 2025); 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. Census tracts: U.S. Census Bureau.