Photo: P199 · CC BY-SA 4.0Très-Saint-Sacrement is on Canada’s flood inventory: 3 listed, led by MRC du Haut Saint Laurent
Burn scars are few around Très-Saint-Sacrement, with 0.1% of the land within 25 km touched by fire since 1986 (0.002% a year). Earthquakes add more: NRCan’s model puts building losses at $0.20 a year per $1,000 of value, against $0.030 for the typical town. In Health Canada’s survey, 8.2% of homes tested in Très-Saint-Sacrement’s area exceeded 200 Bq/m³, close to the typical 6.6%. Hazard risk gives Très-Saint-Sacrement a grade of C−, from earthquakes and radon alone.
What stands out about Très-Saint-Sacrement’s hazards
Four national sources, each read for Très-Saint-Sacrement: earthquakes, radon, past fires and flood studies.
What Très-Saint-Sacrement faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Très-Saint-Sacrement: C−
Earthquake risk and radon make Très-Saint-Sacrement’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. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Très-Saint-Sacrement: 0.1% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Très-Saint-Sacrement’s homes, from the national burned-area record, with the fuel within 5 km.
With 0.002% burned a year, Très-Saint-Sacrement is among the many low-band places (the typical Canadian town 0.000%).
The closest burn since 1986 lies 8.1 km from Très-Saint-Sacrement’s homes, none within 5 km.
Forest fuel is scarce around Très-Saint-Sacrement: 2.9% of the land within 5 km, 4.1% 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 514
Mistissini burns fastest in Quebec at 0.31% a year; Très-Saint-Sacrement, at 0.002%, ranks 35th of 514.
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.
Low, like 92% of the country’s 2,610 towns: the land around Très-Saint-Sacrement burns, but slower than in the 7.5% above it.
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.
3 flood studies cover Très-Saint-Sacrement, the newest from MRC du Haut Saint Laurent
What Canada’s Flood Map Inventory lists for Très-Saint-Sacrement: who studied flooding and where to see their maps.
MRC du Haut Saint Laurent and others have studied flooding in areas that include Très-Saint-Sacrement: 3 studies, the latest from 2016.
| Study | By | Year | Status |
|---|---|---|---|
| Howick | MRC du Haut Saint Laurent | 2016 | final |
| St-Chrysostome-Très-St-Sacrement | MRC du Haut Saint Laurent | 2016 | final |
| St-Martine | Gouvernement du Québec | 1995 | final |
Towns with a flood study on file
Mapping in Quebec reaches 45% of towns, Très-Saint-Sacrement among them, below the 58% across Canada.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
The 2010s brought the most flood studies for Très-Saint-Sacrement (2 of 3), the first dating from the 1990s.
Study dates as the NRCan inventory lists them, one count per study touching Très-Saint-Sacrement.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Très-Saint-Sacrement.
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.
Shaking is Très-Saint-Sacrement’s costliest hazard: $0.20 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Très-Saint-Sacrement’s $0.20 is about 6.5 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
The typical town in Quebec expects $0.14 a year; Très-Saint-Sacrement expects $0.20, and La Pocatière $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 12% of Canada’s 2,611 towns are above Très-Saint-Sacrement.
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 Très-Saint-Sacrement’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).
8.2% of homes tested around Très-Saint-Sacrement are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Radon tests for the Monteregie health region
Très-Saint-Sacrement’s area, at 8.2%, is close to the 6.6% of the typical Canadian town.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Très-Saint-Sacrement is ordinary for towns in Quebec: 8.2%, beside a median of 8.2%.
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: Très-Saint-Sacrement, 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.
One home in Très-Saint-Sacrement can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Très-Saint-Sacrement
Environment and Climate Change Canada issues the weather alerts for Très-Saint-Sacrement; 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 Très-Saint-Sacrement, and listen to local authorities for orders.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Très-Saint-Sacrement’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 |
|---|---|---|---|---|
| Très-Saint-Sacrement | Low | $0.20 | 8.2% | Yes |
| Saint-Étienne-de-Beauharnois 1,151 · 6.8 km | Low | $0.18 | 8.2% | None listed |
| Sainte-Martine 5,884 · 8.2 km | Low | $0.19 | 8.2% | Yes |
| Saint-Urbain-Premier 1,380 · 10 km | Low | $0.19 | 8.2% | None listed |
| Beauharnois 15,285 · 12 km | Low | $0.18 | 8.2% | Yes |
| Saint-Chrysostome 2,641 · 13 km | Low | $0.20 | 8.2% | Yes |
| Saint-Louis-de-Gonzague 2,536 · 15 km | Low | $0.19 | 8.2% | Yes |
Fire is no heavier anywhere nearby than around Très-Saint-Sacrement (low), with Saint-Étienne-de-Beauharnois next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Très-Saint-Sacrement faces
Practical steps for Très-Saint-Sacrement’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
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Très-Saint-Sacrement’s figure is its subdivision’s.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Très-Saint-Sacrement’s homes since 1986, a history of fire that may lower Risk but never raises it.
- 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 Très-Saint-Sacrement floods.
- 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 Très-Saint-Sacrement sits in.
Questions about flooding and hazards in Très-Saint-Sacrement
Is Très-Saint-Sacrement at risk of wildfire?
Not much by Canadian standards: Très-Saint-Sacrement’s band is low, with 0.1% of the land within 25 km burned since 1986 (last in 2025), so wildfire doesn’t change its grade.
Is radon a problem in Très-Saint-Sacrement?
8.2% of the 110 homes Health Canada tested around Très-Saint-Sacrement topped the guideline; your own house needs its own test.
How is Très-Saint-Sacrement’s Hazard risk Grade worked out?
Très-Saint-Sacrement’s Hazard risk grade is C−, built on earthquakes and radon with a one-sided wildfire input.
Does Très-Saint-Sacrement flood?
Très-Saint-Sacrement’s area has been studied for flooding, and the owner’s map shows which streets lie in a zone; the grade leaves flood out.
How big is the earthquake risk in Très-Saint-Sacrement?
In NRCan’s seismic model, Très-Saint-Sacrement’s buildings lose $0.20 per $1,000 of value in an average year.
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).