Photo: Doug Kerr from Albany, NY, United States · CC BY-SA 2.0A flood study covers Alexandria: 3 on the national inventory, the newest from Raisin Region Conservation Authority
For Alexandria, wildfire history is close to nil: 0% of nearby land since 1986, 0.000% a year. Shaking is a bigger worry than in most places, at $0.21 a year per $1,000 of building value ($0.030 typical). Alexandria’s survey area, 6.1% over the radon guideline, is close to the typical town’s 6.6%. Hazard risk gives Alexandria a grade of C, from earthquakes and radon alone.
What stands out about Alexandria’s hazards
Four national sources, each read for Alexandria: earthquakes, radon, past fires and flood studies.
What Alexandria faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Alexandria grades C for hazard risk
For Alexandria, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #840 of 866 in Ontario and #2,078 of 2,589 Canadian towns.
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 Alexandria: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Alexandria’s homes, from the national burned-area record, with the fuel within 5 km.
In a typical year 0.000% of the land near Alexandria burns; the typical Canadian town sees 0.000%, and both are low.
The closest burn since 1986 lies 23 km from Alexandria’s homes, none within 5 km.
Near or far, forest fuel covers a similar share around Alexandria: 9.6% within 5 km and 6.2% 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 Ontario · highest of 871
Near-zero burning puts Alexandria with 638 of the 871 towns in Ontario, far below Sioux Lookout at 0.16%.
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.
Alexandria shares the low band with 92% of Canada’s 2,610 towns, its burn rate rounding to nothing; 7.5% burn faster.
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 Alexandria is mapped in 3 studies, the newest by Raisin Region Conservation Authority
What Canada’s Flood Map Inventory lists for Alexandria: who studied flooding and where to see their maps.
3 studies on the inventory touch Alexandria, the newest Raisin Region Conservation Authority’s from 1983, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Delisle River Flood Plain Mapping and Water Management Study | Raisin Region Conservation Authority | 1983 | final · not public |
| Garry River Water Management Report | Raisin Region Conservation Authority | 1980 | final · not public |
| Riviere au Baudet Flood Plain Mapping and Minor Channel Improvements Study | Raisin Region Conservation Authority | 1977 | final · not public |
Towns with a flood study on file
Flood maps are common in Ontario: 69% of towns have one, against 58% nationally, and Alexandria is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Mapping around Alexandria goes back to the 1970s and peaks in the 1980s, with 2 of its 3 studies.
Study dates as the NRCan inventory lists them, one count per study touching Alexandria.
Flood studies don’t enter the grade; they are listed so you can open the official map for Alexandria.
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 Alexandria’s costliest hazard: $0.21 a year per $1,000
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Roughly 7 times the typical $0.030: Alexandria’s $0.21 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
No town in Ontario expects more earthquake damage than Alexandria ($0.21); the typical one expects $0.043.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Only 7.8% of Canada’s 2,611 towns expect more shaking damage than Alexandria.
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).
The model counts damage to Alexandria’s buildings and their occupants from shaking only: not liquefaction, landslides, tsunami or fires after a quake.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
6.1% of homes tested around Alexandria are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
6.1% of tested homes around Alexandria were over the guideline, much like the typical Canadian town at 6.6%. For radon tests, the only official count covers all of the The Eastern Ontario Health Unit, Alexandria included.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Alexandria’s area, at 6.1%, is above the median in Ontario (4%), and 1% 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.
Radon tops the guideline in a modest share of homes around Alexandria, a band holding 37% of Canada’s 2,611 towns; 26% rank 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.
One home in Alexandria 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 Alexandria
Alerts for Alexandria 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. |
Fire danger and active fires near Alexandria are mapped daily by the Canadian Wildland Fire Information System; evacuation orders come from the municipality or province.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Alexandria faces
Practical steps for Alexandria’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
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Alexandria’s homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- 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 Alexandria’s.
- 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 Alexandria 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 Alexandria sits in.
Questions about flooding and hazards in Alexandria
Is radon a problem in Alexandria?
The area’s survey found 6.1% of 99 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Alexandria.
Is Alexandria at risk of wildfire?
Some, but Alexandria’s low band (0% of nearby land burned since 1986, latest 2020) is short of the level that counts.
Does Alexandria flood?
Alexandria’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 Alexandria?
NRCan’s model expects shaking to cost buildings in Alexandria $0.21 a year for every $1,000 of their value, on average over many years.
How is Alexandria’s Hazard risk Grade worked out?
Alexandria 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).