Photo: Judicieux · CC BY-SA 4.0Wildfire low, radon 8.8%: how Orsainville stands on hazards
For Orsainville, wildfire history is close to nil: 0% of nearby land since 1986, 0.001% a year. Shaking is a bigger worry than in most places, at $0.14 a year per $1,000 of building value ($0.030 typical). Hazard risk gives Orsainville a grade of C−, from earthquakes and radon alone.
What stands out about Orsainville’s hazards
For Orsainville, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Orsainville faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Orsainville: C−
For Orsainville, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #294 of 507 in Quebec and #2,256 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 Orsainville: 0% within 5 km, 0% within 25 km
Past fire around Orsainville’s homes, from the national burned-area record, with the fuel within 5 km.
The yearly burn rate around Orsainville is 0.001%, low beside 0.000% for the typical Canadian town.
Nothing inside 5 km of Orsainville’s homes has burned since 1986, and the nearest scar is 8.8 km off.
Within 5 km of Orsainville, 8% of the land is forest fuel; widen the ring to 25 km and it is 26%.
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
Orsainville burns at 0.001% a year, 136th of 513 towns in Quebec; the leader, 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.
Beside 2,610 Canadian towns, Orsainville reads low, with 92% of them; only 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.
The flood map inventory lists nothing for Orsainville
What Canada’s Flood Map Inventory lists for Orsainville: who studied flooding and where to see their maps.
An empty entry for Orsainville on the inventory isn’t proof of safety; ask locally for flood maps.
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, and Orsainville has none.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping is shown for Orsainville to be opened and checked, never turned into a grade.
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 Orsainville $0.14 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Roughly 4.6 times the typical $0.030: Orsainville’s $0.14 marks real seismic exposure.
Nobody publishes earthquake risk for Orsainville alone, so this card uses the figure for the city of Québec.
Shaking damage a year per $1,000 of building value
The median in Quebec is $0.14; Orsainville, at $0.14, is right beside it, and La Pocatière tops the list 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.
More earthquake risk than most: only 20% of Canada’s 2,611 towns are above Orsainville.
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 Orsainville 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 Orsainville: 8.8% of area homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Area-wide: radon tests, counted over the Capitale-Nationale health region
The survey area of Orsainville reads 8.8%, a shade from the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Orsainville’s area, at 8.8%, is close to the median in Quebec (8.2%); 2.5% 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.
Between 5% and 10% of tests over the guideline: Orsainville, and 37% of Canada’s 2,611 towns; 26% 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, Orsainville’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Orsainville
Alerts for Orsainville 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. |
Alert Ready carries evacuation orders for Orsainville to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Orsainville’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Orsainville | Low | $0.14 | 8.8% | None listed |
| Bourg-Royal 14,430 · 2.5 km | Low | $0.14 | 8.8% | None listed |
| Charlesbourg 9,660 · 2.6 km | Low | $0.14 | 8.8% | None listed |
| Jésuites 15,792 · 3.3 km | Low | $0.14 | 8.8% | None listed |
| Saint-Émile 16,893 · 3.8 km | Low | $0.14 | 8.8% | Yes |
| Notre-Dame-des-Laurentides 16,222 · 4.3 km | Low | $0.14 | 8.8% | Yes |
| Saint-Rodrigue 12,018 · 4.4 km | Low | $0.14 | 8.8% | None listed |
Fire is no heavier anywhere nearby than around Orsainville (low), with Bourg-Royal next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Orsainville faces
Practical steps for Orsainville’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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
- Is earthquake cover included?
What this data can and can’t tell you
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Orsainville without grading them.
- Wildfire counts one way. For Orsainville, 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 Orsainville’s census subdivision (a neighbourhood shows its city’s).
- 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 Orsainville until then.
Questions about flooding and hazards in Orsainville
How big is the earthquake risk in Orsainville?
In NRCan’s seismic model, Orsainville’s buildings lose $0.14 per $1,000 of value in an average year.
Does Orsainville flood?
The inventory has 0 studies for Orsainville, and an empty list isn’t a clean bill: the municipality holds any flood maps.
How is Orsainville’s Hazard risk Grade worked out?
Orsainville’s Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Is Orsainville at risk of wildfire?
Some, but Orsainville’s low band (0% of nearby land burned since 1986, latest 2022) is short of the level that counts.
Is radon a problem in Orsainville?
The area’s survey found 8.8% of 160 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Orsainville.
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).