Photo: Jeangagnon · CC BY-SA 3.0Hazard risk in Berthier-sur-Mer is higher than in 93% of Canadian towns
Since 1986 almost nothing has burned near Berthier-sur-Mer: 0% of the land within 25 km, or 0.000% a year. Shaking is a bigger worry than in most places, at $0.16 a year per $1,000 of building value ($0.030 typical). More homes than usual carry radon here, 13% over the guideline where the typical town has 6.6%. Hazard risk gives Berthier-sur-Mer a grade of D, from earthquakes and radon alone.
What stands out about Berthier-sur-Mer’s hazards
For Berthier-sur-Mer, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Berthier-sur-Mer faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Berthier-sur-Mer grades D for hazard risk
Two inputs always count for Berthier-sur-Mer, earthquakes and radon; the third, wildfire, counts only against a town.
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 Berthier-sur-Mer has burned: 0% within 5 km, 0% within 25 km since 1986
Past fire around Berthier-sur-Mer’s homes, from the national burned-area record, with the fuel within 5 km.
A burn rate of 0.000% a year keeps Berthier-sur-Mer in the low band (the typical Canadian town: 0.000%).
The 5 km ring around Berthier-sur-Mer’s homes is clear of burns since 1986, the nearest 16 km out.
Close to Berthier-sur-Mer there is little to burn (3.7% forest fuel within 5 km), but 33% of the land within 25 km is forest.
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
To three decimals the burn rate around Berthier-sur-Mer is zero, as for 145 of the 514 towns in Quebec, while Mistissini reaches 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.
Most of the country’s 2,610 towns are low-band (92%, against 7.5% above); around Berthier-sur-Mer, burning rounds to zero.
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.
The flood map inventory lists nothing for Berthier-sur-Mer
What Canada’s Flood Map Inventory lists for Berthier-sur-Mer: who studied flooding and where to see their maps.
The inventory has nothing for Berthier-sur-Mer, but a local or conservation-authority map may still exist.
Towns with a flood study on file
Only 45% of towns in Quebec have a flood study, short of Canada’s 58%, and Berthier-sur-Mer is not among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood is shown here, never graded: a study says where a map exists, not how many of Berthier-sur-Mer’s homes stand in a flood zone.
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.”
Shaking is Berthier-sur-Mer’s costliest hazard: $0.16 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.16 per $1,000, Berthier-sur-Mer carries roughly 5.4 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Earthquake risk around Berthier-sur-Mer ($0.16) matches the middle in Quebec ($0.14), far from La Pocatière’s $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.
More earthquake risk than most: only 14% of Canada’s 2,611 towns are above Berthier-sur-Mer.
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).
For Berthier-sur-Mer the model prices shaking damage to buildings, nothing more.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Test for radon in Berthier-sur-Mer: 13% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Measured across the Chaudiere-Appalaches health region: radon tests
At 13% over the guideline, the area around Berthier-sur-Mer beats the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Berthier-sur-Mer, 13% of tests were over 200 Bq/m³ and 0.6% over 600, against a median of 8.2% in Quebec.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Berthier-sur-Mer is in the 10–20% band, with 22% of Canada’s 2,611 towns; only 4.6% are 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, Berthier-sur-Mer’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Berthier-sur-Mer
Environment and Climate Change Canada issues the weather alerts for Berthier-sur-Mer; Alert Ready carries the urgent ones to phones, radio and TV.
| 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. |
In fire season, check CWFIS for danger and active fires around Berthier-sur-Mer, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Berthier-sur-Mer
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Berthier-sur-Mer | Low | $0.16 | 13% | None listed |
| Saint-François-de-la-Rivière-du-Sud 1,550 · 7.0 km | Low | $0.15 | 13% | None listed |
| Saint-Vallier 1,026 · 9.2 km | Low | $0.13 | 13% | None listed |
| Montmagny 11,326 · 13 km | Low | $0.19 | 13% | Yes |
| Saint-Jean-de-l'Île-d'Orléans 1,006 · 14 km | Low | $0.13 | 8.8% | None listed |
| Saint-Raphaël 2,488 · 15 km | Low | $0.11 | 13% | None listed |
| Saint-Michel-de-Bellechasse 1,902 · 17 km | Low | $0.13 | 13% | None listed |
None of the places around has more fire nearby than Berthier-sur-Mer (low); Saint-François-de-la-Rivière-du-Sud comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Berthier-sur-Mer faces
What to do about the hazards Berthier-sur-Mer 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.
- Drop, cover and hold on.
- Strap the water heater down.
- Keep 72 hours of supplies.
- Has it had a radon test?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Berthier-sur-Mer’s included.
- Wildfire counts one way. Burned land within 25 km of where people live, averaged over 1986–2025 and checked for fuel near homes, is the measure; it looks back, not ahead, and only ever counts against Berthier-sur-Mer.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Berthier-sur-Mer without grading them.
- 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 Berthier-sur-Mer until then.
Questions about flooding and hazards in Berthier-sur-Mer
Is Berthier-sur-Mer at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Berthier-sur-Mer has burned since 1986, the last in 2022, a low band that leaves Risk alone.
How big is the earthquake risk in Berthier-sur-Mer?
NRCan’s model expects shaking to cost buildings in Berthier-sur-Mer $0.16 a year for every $1,000 of their value, on average over many years.
Does Berthier-sur-Mer flood?
Nothing is listed for Berthier-sur-Mer on the national inventory (0); local maps may still exist with the municipality.
Is radon a problem in Berthier-sur-Mer?
In Health Canada’s survey, 13% of 175 homes tested in Berthier-sur-Mer’s area were above 200 Bq/m³, though only a test tells you about one house.
How is Berthier-sur-Mer’s Hazard risk Grade worked out?
Berthier-sur-Mer’s Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
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).