Photo: Hayden Soloviev · CC BY 4.0A flood study covers Lacolle: 1 on the national inventory, the newest from Gouvernement du Québec
Since 1986 almost nothing has burned near Lacolle: 0% of the land within 25 km, or 0.000% a year. Seismic risk runs high: $0.17 of expected damage per $1,000 of buildings a year, the typical town $0.030. Radon is about average around Lacolle: 8.2% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Lacolle a grade of C−, from earthquakes and radon alone.
What stands out about Lacolle’s hazards
For Lacolle, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Lacolle faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Lacolle: C−
Earthquake risk and radon make Lacolle’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
Its place: #290 of 507 in Quebec and #2,251 of 2,589 Canadian towns.
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.
Few fires near Lacolle: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Lacolle’s residents live, and the fuel next to their homes.
At 0.000% of the land a year, Lacolle’s burn rate is in the low band; the typical Canadian town sees 0.000%.
Homes in Lacolle sit on open or built-up ground (3.6% forest fuel within 5 km); the wider 25 km holds 5%.
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 513
Fire has taken almost none of the land around Lacolle, as for 144 of the 513 towns in Quebec; Mistissini tops the list 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.
Like most of Canada’s 2,610 towns (92%), Lacolle is in the low band, with a burn rate of zero to three decimals; 7.5% rank 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.
Gouvernement du Québec has mapped flooding for Lacolle (1 study)
Flood studies whose area touches Lacolle, from NRCan’s inventory, each linked to its owner.
Gouvernement du Québec studied flooding in an area that includes Lacolle (2004); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Brome-Missisquoi-Haut-Richelieu-Vallée-du-Richelieu-Rouville | Gouvernement du Québec | 2004 | final |
Towns with a flood study on file
Lacolle 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.
Listed, not scored: a flood study proves a map exists, not that Lacolle 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.
Earthquakes cost buildings in Lacolle $0.17 per $1,000 a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
Roughly 5.6 times the typical $0.030: Lacolle’s $0.17 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
About level with the typical town in Quebec: Lacolle’s $0.17 against $0.14; La Pocatière reaches $0.48.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Lacolle sits above most of Canada’s 2,611 towns on earthquake risk; 14% are higher.
Each column: the share of Canada’s towns of 2,500 people or more in that range of yearly loss per $1,000 (NRCan, 2022).
Only shaking damage to buildings in Lacolle is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Some radon around Lacolle: 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.
Around Lacolle, 8.2% of tested homes topped the guideline, near the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Lacolle is ordinary for towns in Quebec: 8.2%, beside a median of 8.2%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
37% of Canada’s 2,611 towns share Lacolle’s band of 5 to 10%; 26% sit higher.
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, Lacolle’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests: the Monteregie health region
Where to get warnings in Lacolle
Alerts for Lacolle 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 Lacolle 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)
Hazards in the places around Lacolle
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Lacolle | Low | $0.17 | 8.2% | Yes |
| Noyan 1,576 · 5.9 km | Low | $0.17 | 8.2% | Yes |
| Saint-Paul-de-l'Île-aux-Noix 2,321 · 6.2 km | Low | $0.18 | 8.2% | Yes |
| Saint-Bernard-de-Lacolle 1,655 · 8.6 km | Low | $0.17 | 8.2% | None listed |
| Saint-Cyprien-de-Napierville 1,786 · 10 km | Low | $0.15 | 8.2% | None listed |
| Napierville 4,187 · 13 km | Low | $0.18 | 8.2% | None listed |
| Saint-Blaise-sur-Richelieu 2,165 · 15 km | Low | $0.18 | 8.2% | Yes |
Saint-Cyprien-de-Napierville burns a little more than Lacolle, in the same low band (low here).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Lacolle faces
Practical steps for Lacolle’s hazards, most pressing first.
- 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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Check the address on the flood map.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Lacolle’s census subdivision (a neighbourhood shows its city’s).
- Flood studies aren’t flood zones. A study’s area can be a whole watershed or province, so being on the inventory says a map exists, not that a home in Lacolle floods.
- Wildfire counts one way. For Lacolle, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Radon is a survey. The radon share comes from about 14,000 long-term home tests in 2009–2011, pooled for now by the 2007 health region Lacolle sits in.
Questions about flooding and hazards in Lacolle
How is Lacolle’s Hazard risk Grade worked out?
Lacolle’s Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Is Lacolle at risk of wildfire?
No meaningful wildfire history near Lacolle: 0% of nearby land since 1986, band low.
How big is the earthquake risk in Lacolle?
About $0.17 a year per $1,000 of building value, NRCan’s long-run expectation for Lacolle.
Is radon a problem in Lacolle?
The area’s survey found 8.2% of 110 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Lacolle.
Does Lacolle flood?
Lacolle’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
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).