Photo: busand2003 · CC BY 3.0Radon is Grande-Rivière’s main hazard: 25% of tested homes in its area top Health Canada’s guideline
For Grande-Rivière, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. Seismic risk runs low: $0.015 of expected damage per $1,000 of buildings a year, the typical town $0.030. Grande-Rivière grades C for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Grande-Rivière’s hazards
Four national sources, each read for Grande-Rivière: earthquakes, radon, past fires and flood studies.
What Grande-Rivière faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Grande-Rivière grades C for hazard risk
Two inputs always count for Grande-Rivière, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #128 of 507 in Quebec and #2,058 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around Grande-Rivière has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Grande-Rivière’s residents live, and the fuel next to their homes.
Low by Canadian standards: 0.000% of the land a year around Grande-Rivière, 0.000% for the typical Canadian town.
Near or far, forest fuel covers a similar share around Grande-Rivière: 84% within 5 km and 88% within 25 km.
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
Of the 513 towns in Quebec, 144 have a burn rate that rounds to zero, Grande-Rivière among them; Mistissini leads at 0.31% a year.
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.
Measured against 2,610 towns, Grande-Rivière is in the largest group, low (92%), and at its floor, while 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.
No flood study is listed for Grande-Rivière
Flood studies whose area touches Grande-Rivière, from NRCan’s inventory, each linked to its owner.
No flood study on the national inventory covers Grande-Rivière; ask the municipality, which is the authority for its flood maps.
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, and Grande-Rivière has none.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The grade leaves flood out, since a study area says nothing about how many of Grande-Rivière’s homes are at risk.
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.”
Earthquakes cost buildings in Grande-Rivière just $0.015 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.
Grande-Rivière’s $0.015 is a fraction of the typical town’s $0.030 (0.5 times as much): quiet ground by Canadian standards.
Shaking damage a year per $1,000 of building value
At $0.015, Grande-Rivière is below the typical town in Quebec ($0.14); La Pocatière is highest at $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.
Earthquakes cost less around Grande-Rivière than in 72% of Canada’s 2,611 towns.
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).
Roads, pipes and bridges aren’t in Grande-Rivière’s figure, nor landslides or tsunami: it is buildings and shaking.
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 Grande-Rivière: 25% of area homes were over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Radon runs above the typical Canadian town (6.6%) in Grande-Rivière’s area, at 25%. For radon tests, the only official count covers all of the Gaspesie - Iles-de-la-Madeleine health region, Grande-Rivière included.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Grande-Rivière’s area, at 25%, is above the median in Quebec (8.2%), and 3.4% of its tests passed 600 Bq/m³.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Few of Canada’s 2,611 towns (3.1%) share the 20–30% band with Grande-Rivière, and 1.5% sit above it.
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.
The share describes the area, not a house: in Grande-Rivière as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Grande-Rivière
Environment and Climate Change Canada issues the weather alerts for Grande-Rivière; 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. |
For fires near Grande-Rivière, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Grande-Rivière’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Grande-Rivière | Low | $0.015 | 25% | None listed |
| Sainte-Thérèse-de-Gaspé 1,009 · 7.4 km | Low | $0.015 | 25% | None listed |
| Chandler 7,323 · 16 km | Low | $0.020 | 25% | None listed |
Among its neighbours Grande-Rivière has the most fire on record (low); Sainte-Thérèse-de-Gaspé follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Grande-Rivière faces
What to do about the hazards Grande-Rivière 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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Earthquakes are modelled. Shaking damage is modelled from the ground, the buildings and the odds of each quake, and published for whole subdivisions such as Grande-Rivière’s.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Grande-Rivière.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Grande-Rivière’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Grande-Rivière takes its 2007 health region’s share.
Questions about flooding and hazards in Grande-Rivière
How big is the earthquake risk in Grande-Rivière?
About $0.015 a year per $1,000 of building value, NRCan’s long-run expectation for Grande-Rivière.
Is Grande-Rivière at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Grande-Rivière since 1986, a low band, though small grass fires aren’t mapped.
Does Grande-Rivière flood?
Nothing is listed for Grande-Rivière on the national inventory (0); local maps may still exist with the municipality.
Is radon a problem in Grande-Rivière?
In Health Canada’s survey, 25% of 174 homes tested in Grande-Rivière’s area were above 200 Bq/m³, though only a test tells you about one house.
How is Grande-Rivière’s Hazard risk Grade worked out?
Grande-Rivière grades C for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers 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).