Photo: Esprqii · CC BY-SA 3.0FEMA puts Lake Oswego’s expected hazard damage per building above that of 63% of U.S. towns, mostly from river and rain flooding
On FEMA’s National Risk Index, Lake Oswego gets a C+ for hazard risk: higher expected damage per building than 63% of U.S. towns, #54 of 142 in Oregon. Most of that expected damage is river and rain flooding (51%), then earthquakes (47%). Flood insurance has paid 56 claims here since 1996.
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 stands out about Lake Oswego’s natural hazards
From FEMA’s model and FEMA’s records, below.
What Lake Oswego 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
Earthquakes
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 Lake Oswego’s grade
River and rain flooding is 51% of the building damage FEMA expects in Lake Oswego, and Lake Oswego’s rate of river and rain flooding damage is lower than 53% of U.S. census tracts. Next is earthquakes at 47% (higher than 87% of U.S. census tracts).
C+ #54 of 142 in Oregon; higher expected damage per building than 63% of U.S. towns (21,298).
Lake Oswego’s residents live in 16 census tracts; FEMA’s figures are combined by where they live.
The typical Oregon town has higher expected damage than 69% of U.S. towns; within the state, Lake Oswego has less expected damage per building than 62% of Oregon towns.
In dollars, FEMA expects about $24.8M a year in losses across Lake Oswego: $17.2M to buildings, the rest to people and crops.
Does Lake Oswego flood? Sometimes: 56 flood claims since 1996
Every paid claim on a federal flood insurance policy in Lake Oswego, from FEMA’s records: 3.1 per 1,000 homes, fewer than 51% of the 13,809 U.S. towns with a flood insurance record.
Lake Oswego isn’t in FEMA’s Community Rating System, which cuts flood insurance up to 45% in towns that do extra flood-proofing.
Insurance rates: Clackamas County.6 federal disasters brought FEMA money to Lake Oswego
Disasters that paid out in Lake Oswego itself (aid to households or repair grants to the City of Lake Oswego), newest first, with that year’s flood claims.
- 2025Severe Storms, Straight-line Winds, Flooding, Landslides, and Mudslides$20K to the City of Lake Oswego for repairs
- 2024Severe Winter Storms, Straight-line Winds, Landslides, and Mudslides$881K to the City of Lake Oswego for repairs
- 2021Severe Winter Storm$847K to the City of Lake Oswego for repairs2 flood claims paid that year
- 2020Wildfires and Straight-line Winds99 households applied for aid$6K aid approved$18K to the City of Lake Oswego for repairs1 flood claim paid that year
- 2015Severe Winter Storms, Straight-line Winds, Flooding, Landslides, and Mudslides$332K to the City of Lake Oswego for repairs1 flood claim paid that year
- 2008Severe Winter Storm, Record and Near Record Snow$119K to the City of Lake Oswego for repairs
Clackamas County has had 15 natural disasters declared by the President since 1953, most often severe storms, then floods. Not counted: the 2005 Hurricane Katrina evacuee emergency, which covered counties that took in evacuees.
Also 5 FEMA wildfire suppression grants (Fire Management Assistance, not a disaster declaration) for fires in Clackamas County, 2014–2022.
Old photos of Lake Oswego after a storm or flood belong in the town’s history. Add one, or share what you remember below.
Add to the Lake Oswego archive →Lake Oswego and its neighbors
Lake Oswego is 3rd of the 6 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 |
|---|---|---|---|
| Tualatin | C+more damage than 59% | river and rain flooding | 44 |
| Stafford | C+more damage than 60% | river and rain flooding | 3 |
| Lake Oswego | C+more damage than 63% | river and rain flooding | 56 |
| West Linn | C+more damage than 64% | river and rain flooding | 43 |
| Portland | Cmore damage than 69% | earthquakes | 167 |
| Oak Grove | Cmore damage than 71% | earthquakes | 49 |
| Rivergrove | — | 657 residents; we grade 1,000+ | |
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 Lake Oswego 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.
- Drop, cover and hold on.
- Strap tall furniture and the water heater to the wall.
- Know how to shut off the gas.
- 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 Lake Oswego
Is Lake Oswego at risk for natural disasters?
On FEMA’s National Risk Index, Lake Oswego has higher expected damage per building than 63% of U.S. towns: C+ for hazard risk, #54 of 142 in Oregon. Most of the expected damage is river and rain flooding (51%) and earthquakes (47%). This is FEMA’s model of an average year for today’s buildings, not a forecast.
Does Lake Oswego flood?
Flood insurance has paid 56 claims in Lake Oswego since 1996, $3.8M in all, or 3.1 per 1,000 homes, fewer than 51% of U.S. towns with a flood insurance record.
Is Lake Oswego 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 Clackamas County, 41% of homes in mapped flood zones carry federal flood insurance, and 0.9% of all homes do.
How much is flood insurance in Lake Oswego?
FEMA’s Community Rating System list shows no discount for Lake Oswego’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 Lake Oswego?
By FEMA money that reached Lake Oswego, Severe Winter Storms, Straight-line Winds, Landslides, and Mudslides (2024): $881K to the City of Lake Oswego for repairs.
Is Lake Oswego at risk from river and rain flooding?
It is the largest share of the building damage FEMA expects here (51%), and Lake Oswego’s rate for it is lower than 53% of U.S. census tracts.
Storm stories
Memories, warnings and help from neighbors in Lake Oswego.
Sources: FEMA National Risk Index v1.20 (December 2025), census-tract table, combined by where Lake Oswego’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.