Photo: P199 · CC BY-SA 3.0Bristol faces more hazards than 88% of Canadian towns
Wildfire isn’t Bristol’s worry: 0% of the land within 25 km burned since 1986 (0.001% a year). Earthquakes add more: NRCan’s model puts building losses at $0.11 a year per $1,000 of value, against $0.030 for the typical town. Radon is higher than usual: 13% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Bristol a grade of D, from earthquakes and radon alone.
What stands out about Bristol’s hazards
For Bristol, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Bristol faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Bristol grades D for hazard risk
Earthquake risk and radon make Bristol’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. Only 63 homes were tested in the survey area, so the radon share is rough. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Little of the land around Bristol has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Bristol’s residents live, and the fuel next to their homes.
Low by Canadian standards: 0.001% of the land a year around Bristol, 0.000% for the typical Canadian town.
No fire has burned within 5 km of Bristol’s homes since 1986; the nearest burn is 11 km away.
About as much forest grows next to Bristol’s homes (21% within 5 km) as across 25 km (22%).
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
Bristol burns at 0.001% a year, 136th of 514 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.
Some fire is mapped around Bristol, but not enough to leave the low band, where 92% of Canada’s 2,610 towns are; 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.
Flooding around Bristol is mapped in 2 studies, the newest by Municipalité de Pontiac
Flood studies whose area touches Bristol, from NRCan’s inventory, each linked to its owner.
The newest of 2 studies covering Bristol is Municipalité de Pontiac’s, from 2016; open its map to see the zones.
| Study | By | Year | Status |
|---|---|---|---|
| Gatineau-Argenteuil-Collindes-de-l'Outaouais | Municipalité de Pontiac | 2016 | final |
| Chenal-du-Grand-Calumet-Rocher-Fendu | MRC de Pontiac | 2006 | final |
Towns with a flood study on file
Its flood study sets Bristol apart in Quebec, where 45% of towns have one (Canada: 58%).
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping around Bristol has come in steps: 2 studies from the 2000s to the 2010s.
Study dates as the NRCan inventory lists them, one count per study touching Bristol.
Flood mapping is shown for Bristol 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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Earthquakes cost buildings in Bristol $0.11 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.
Bristol’s $0.11 is about 3.7 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Shaking damage a year per $1,000 of building value
At $0.11, Bristol 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.
More earthquake risk than most: only 25% of Canada’s 2,611 towns are above Bristol.
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 Bristol 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).
13% of homes tested around Bristol are over the radon 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 Bristol’s area, at 13%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Bristol, 13% of tests were over 200 Bq/m³ and 4.8% 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.
4.6% of Canada’s 2,611 towns have a higher share of homes over 200 Bq/m³ than Bristol, in the 10–20% band with 22%.
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, Bristol’s included, whatever the area’s figure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Data for radon tests covers the Outaouais health region
Where to get warnings in Bristol
Alerts for Bristol 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 Bristol 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 Bristol’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Bristol | Low | $0.11 | 13% | Yes |
| Arnprior 11,459 · 10 km | Low | $0.11 | 8% | None listed |
| Shawville 1,729 · 12 km | Low | $0.11 | 13% | None listed |
| McNab/Braeside 8,340 · 13 km | Low | $0.11 | 8% | Yes |
| Horton 3,550 · 14 km | Low | $0.098 | 8% | Yes |
| Clarendon 1,442 · 18 km | Low | $0.11 | 13% | Yes |
Shawville (low) has the heaviest fire record of Bristol’s neighbours, and Bristol (low) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Bristol faces
Practical steps for Bristol’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
- 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 Bristol sits in.
- 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 Bristol.
- 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 Bristol floods.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Bristol’s included.
Questions about flooding and hazards in Bristol
Does Bristol flood?
Bristol’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
Is radon a problem in Bristol?
13% of the 63 homes Health Canada tested around Bristol topped the guideline; your own house needs its own test.
How big is the earthquake risk in Bristol?
About $0.11 a year per $1,000 of building value, NRCan’s long-run expectation for Bristol.
Is Bristol at risk of wildfire?
Not much by Canadian standards: Bristol’s band is low, with 0% of the land within 25 km burned since 1986 (last in 2025), so wildfire doesn’t change its grade.
How is Bristol’s Hazard risk Grade worked out?
Bristol’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).