Photo: Conrad Poirier · Public domainA flood study covers Kahnawake: 2 on the national inventory, the newest from Gouvernement du Québec
Little of the land around Kahnawake has burned: 0% within 25 km since 1986, or 0.001% a year. About as many homes carry radon around Kahnawake as elsewhere, 8.2% over the guideline where the typical town has 6.6%. Kahnawake can’t get a Hazard risk grade: NRCan’s seismic model has no figure for it.
What stands out about Kahnawake’s hazards
For Kahnawake, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Kahnawake faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Radon
Flood study
No Hazard risk grade is possible for Kahnawake
Risk averages earthquakes and radon; wildfire joins only where it pulls the average down, so a town like Kahnawake with little fire nearby would get no credit for it.
Kahnawake is a First Nations reserve: no overall grade, no ranking.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Little of the land around Kahnawake has burned: 0.3% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Kahnawake’s residents live, and the fuel next to their homes.
A burn rate of 0.001% a year keeps Kahnawake in the low band (the typical Canadian town: 0.000%).
Forest makes up 2% of the land within 5 km of Kahnawake and 0.6% within 25 km, little for a forest fire to run through.
Shares of land within 5 and 25 km of populated blocks: burned at least once in 1986–2025 (CWFIS burned-area composite), forest fuel and grass (fire behaviour fuel types, 2026, 250 m grid).
Burn rate a year, towns in Quebec · highest of 514
At 0.001% a year, Kahnawake ranks 136th of the 514 towns in Quebec; Mistissini leads at 0.31%.
Each bar: the yearly average share of land within 25 km of a town’s homes that burned, 1986–2025 (CWFIS); the seven highest towns of 2,500 people or more.
Kahnawake is in the low band with 92% of Canada’s 2,610 towns; 7.5% sit in moderate or higher.
Bands of the yearly burn rate: low under 0.05%, moderate under 0.25%, high under 1%, very high 1% or more; towns of 2,500 people or more.
Fire danger and active fires (CWFIS)
Canadian Wildland Fire Information System: National Burned Area Composite 1986–2025 and fire behaviour fuel types (2026), Natural Resources Canada. Measured within 25 km and 5 km of each populated dissemination area; past fire, not a forecast.
2 flood studies cover Kahnawake, the newest from Gouvernement du Québec
Flood studies whose area touches Kahnawake, from NRCan’s inventory, each linked to its owner.
2 studies on the inventory touch Kahnawake, the newest Gouvernement du Québec’s from 2008, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| St-Constant-St-Isidore | Gouvernement du Québec | 2008 | final |
| St-Louis-Varennes | Gouvernement du Québec | 1977 | final |
Towns with a flood study on file
Kahnawake is one of the 45% of towns in Quebec with a flood study on file, fewer than Canada’s 58%.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
No single decade dominates: 2 studies for Kahnawake between the 1970s and the 2000s.
Study dates as the NRCan inventory lists them, one count per study touching Kahnawake.
Listed, not scored: a flood study proves a map exists, not that Kahnawake floods.
The inventory’s own caution (NRCan): “The Canada Flood Map (CFM) does not include every flood hazard map in Canada and may be incomplete or contain inaccuracies. It should not be relied upon as the official source of flood mapping information. Furthermore, if a map appears to be missing, this does not necessarily mean that the area has never been mapped. For the official version of a map, updated information, or confirmation of applicable regulations, please contact the local authority responsible for flood mapping.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Some radon around Kahnawake: 8.2% of area homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
8.2% of tested homes around Kahnawake were over the guideline, much like the typical Canadian town at 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Kahnawake’s area, at 8.2%, is close to the median in Quebec (8.2%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
26% of Canada’s 2,611 towns have more homes over 200 Bq/m³ than Kahnawake’s 5–10% band, which holds 37%.
Each bar: the share of Canada’s towns of 2,500 people or more whose survey area had that share of tests over 200 Bq/m³.
Health Canada advises testing every home, Kahnawake’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Area behind the radon tests figures: the Monteregie health region
Where to get warnings in Kahnawake
Alerts for Kahnawake come from Environment and Climate Change Canada and, for emergencies, Alert Ready.
| Alert | What it means |
|---|---|
| Warning | Severe weather is happening or about to: act now. |
| Watch | Conditions favour severe weather: be ready. |
| Advisory | Weather that is less severe but could disrupt the day. |
| Special weather statement | Unusual weather worth knowing about. |
| Special air quality statement | Poor air, often wildfire smoke. |
Evacuation orders for Kahnawake come from the municipality or the province, while CWFIS maps fire danger every day.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Kahnawake’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Kahnawake | Low | – | 8.2% | Yes |
| Châteauguay 53,508 · 4.5 km | Low | $0.20 | 8.2% | Yes |
| Vieux-Lachine - Saint-Pierre 31,113 · 6.3 km | Low | $0.20 | 6.8% | None listed |
| Cecil-P.-Newman 34,965 · 6.4 km | Low | $0.20 | 6.8% | None listed |
| Lachine-Ouest 15,315 · 6.5 km | Low | $0.20 | 6.8% | None listed |
| Sault-Saint-Louis 47,270 · 7.8 km | Low | $0.20 | 6.8% | None listed |
| Montréal-Ouest 5,197 · 8.1 km | Low | $0.19 | 6.8% | None listed |
The neighbour with the most fire is Châteauguay (low), still no more than Kahnawake (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Kahnawake faces
What to do about the hazards Kahnawake faces, and what to ask before you buy.
- Test for three months in winter.
- Over 200 Bq/m³: fix it.
- Kits are cheap; pros test too.
- Never drive through floodwater.
- Move papers and medicines upstairs.
- Ask whether your street is mapped.
- Clear needles and wood nearby.
- Keep a grab-and-go bag ready.
- In smoke, stay in; filter air.
- Has it had a radon test?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Radon is a survey. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Kahnawake until then.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Kahnawake without grading them.
- Wildfire counts one way. For Kahnawake, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Kahnawake’s census subdivision (a neighbourhood shows its city’s).
Questions about flooding and hazards in Kahnawake
Does Kahnawake flood?
A flood study covers Kahnawake on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is radon a problem in Kahnawake?
Around Kahnawake, 110 survey homes were tested and 8.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
How is Kahnawake’s Hazard risk Grade worked out?
Risk needs earthquakes, radon and wildfire, and Kahnawake is missing one, so there will be no grade.
Is Kahnawake at risk of wildfire?
Fire has reached 0% of the land around Kahnawake since 1986 (last in 2025); at low, it neither helps nor hurts the grade.
Seismic risk: Natural Resources Canada. Radon: Health Canada. Wildfire: Canadian Wildland Fire Information System. Flood studies: Natural Resources Canada, Canada Flood Map Inventory. Contains information licensed under the Open Government Licence – Canada.
Sources: NRCan, Canada’s Seismic Risk Model 2022 · Health Canada, Cross-Canada Survey of Radon Concentrations in Homes · CWFIS, National Burned Area Composite and FBP fuel types · NRCan, Canada Flood Map Inventory. Under the Statistics Canada Open Licence.
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).