Photo: Félix Mathieu-Bégin · CC BY-SA 4.0On hazards, Saint-Gilles comes out behind 91% of Canadian towns
Fire seldom reaches Saint-Gilles: since 1986, 0% of the land within 25 km has burned (0.000% a year). Shaking is a bigger worry than in most places, at $0.13 a year per $1,000 of building value ($0.030 typical). Radon is higher than usual: 13% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Saint-Gilles grades D for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Saint-Gilles’s hazards
For Saint-Gilles, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Saint-Gilles faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Saint-Gilles: D
Two inputs always count for Saint-Gilles, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #474 of 507 in Quebec and #2,480 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 Saint-Gilles: 0% within 5 km, 0% within 25 km
Past fire around Saint-Gilles’ homes, from the national burned-area record, with the fuel within 5 km.
Forty years of fire maps put Saint-Gilles at 0.000% a year, low next to the typical Canadian town’s 0.000%.
Forest crowds in on Saint-Gilles: 65% of the land within 5 km is forest fuel, more than the 29% 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
Little or nothing burns around Saint-Gilles in a typical year; 144 of the 513 towns in Quebec share that, and Mistissini leads 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.
Measured against 2,610 towns, Saint-Gilles 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.
Flooding around Saint-Gilles is mapped in 2 studies, the newest by Ville de Lévis
What Canada’s Flood Map Inventory lists for Saint-Gilles: who studied flooding and where to see their maps.
For Saint-Gilles the inventory points to 2 studies, most recently Ville de Lévis’s in 2008.
| Study | By | Year | Status |
|---|---|---|---|
| Ville de Lévis | Ville de Lévis | 2008 | final |
| St-Gilles | Gouvernement du Québec | 2005 | final |
Towns with a flood study on file
Flood maps are thinner in Quebec, 45% of towns against 58% nationally, but Saint-Gilles has one.
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 Saint-Gilles’ 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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
High seismic risk in Saint-Gilles: $0.13 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
The typical town loses $0.030 a year to shaking; Saint-Gilles loses $0.13, 4.4 times as much.
Shaking damage a year per $1,000 of building value
Shaking damage around Saint-Gilles runs at $0.13 a year, near the $0.14 of the typical town in Quebec; La Pocatière has $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.
In the upper part of Canada’s range: 22% of its 2,611 towns expect more damage than Saint-Gilles.
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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Saint-Gilles.
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 Saint-Gilles are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
More homes than usual test high around Saint-Gilles: 13% against 6.6% for the typical Canadian town. Nobody publishes radon tests for Saint-Gilles alone, so this card uses the figure for the Chaudiere-Appalaches health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Saint-Gilles than in most towns in Quebec: 13% over the guideline (8.2% is typical), 0.6% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
More high tests than most: Saint-Gilles sits in a band that only 22% of Canada’s 2,611 towns share, with 4.6% above.
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.
A low area share in Saint-Gilles doesn’t clear a house, nor does a high one condemn it: test.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Where to get warnings in Saint-Gilles
Environment and Climate Change Canada issues the weather alerts for Saint-Gilles; 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 Saint-Gilles, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Saint-Gilles
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Saint-Gilles | Low | $0.13 | 13% | Yes |
| Saint-Narcisse-de-Beaurivage 1,303 · 8.5 km | Low | $0.11 | 13% | None listed |
| Saint-Agapit 4,817 · 9.2 km | Low | $0.13 | 13% | Yes |
| Saint-Lambert-de-Lauzon 7,551 · 13 km | Low | $0.14 | 13% | None listed |
| Sainte-Agathe-de-Lotbinière 1,042 · 14 km | Low | $0.091 | 13% | None listed |
| Saint-Patrice-de-Beaurivage 1,091 · 14 km | Low | $0.098 | 13% | None listed |
| Saint-Bernard 2,680 · 16 km | Low | $0.10 | 13% | None listed |
Saint-Gilles’ low band tops its neighbours; Saint-Narcisse-de-Beaurivage is next (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Saint-Gilles faces
What to do about the hazards Saint-Gilles 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?
- 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
- 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 Saint-Gilles floods.
- Wildfire counts one way. For Saint-Gilles, 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 Saint-Gilles’ census subdivision (a neighbourhood shows its city’s).
- 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 Saint-Gilles sits in.
Questions about flooding and hazards in Saint-Gilles
How is Saint-Gilles’s Hazard risk Grade worked out?
Saint-Gilles’ Hazard risk grade is D, built on earthquakes and radon with a one-sided wildfire input.
Is Saint-Gilles at risk of wildfire?
Fire has reached 0% of the land around Saint-Gilles since 1986 (last in 2018); at low, it neither helps nor hurts the grade.
How big is the earthquake risk in Saint-Gilles?
In NRCan’s seismic model, Saint-Gilles’ buildings lose $0.13 per $1,000 of value in an average year.
Does Saint-Gilles flood?
Saint-Gilles’ 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 Saint-Gilles?
Around Saint-Gilles, 175 survey homes were tested and 13% came in over 200 Bq/m³, a guide to the area, not to any one home.
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).