Photo: JFVoll · CC BY-SA 4.0Flood mapping exists for Erin: 5 on record, latest by Grand River Conservation Authority
The burned-area map is nearly blank around Erin, 0% within 25 km since 1986, 0.000% a year. Seismic risk in Erin sits near the middle: $0.018 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, 11% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Erin grades B for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Erin’s hazards
Four national sources, each read for Erin: earthquakes, radon, past fires and flood studies.
What Erin faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Erin grades B for hazard risk
The grade weighs Erin’s seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
Its place: #641 of 866 in Ontario and #1,554 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.
Few fires near Erin: 0% within 5 km, 0% within 25 km
Past fire around Erin’s homes, from the national burned-area record, with the fuel within 5 km.
The land within 25 km of Erin burns at 0.000% a year on average, the low band; the typical Canadian town: 0.000%.
More forest grows near Erin’s homes (19% within 5 km) than across 25 km (12%).
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
To three decimals the burn rate around Erin is zero, as for 638 of the 871 towns in Ontario, while Sioux Lookout reaches 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.
Like most of Canada’s 2,610 towns (92%), Erin is in the low band, with a burn rate of zero to three decimals; 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.
Erin is on the flood map inventory: 5 studies, latest by Grand River Conservation Authority
What Canada’s Flood Map Inventory lists for Erin: who studied flooding and where to see their maps.
5 studies on the inventory touch Erin, the newest Grand River Conservation Authority’s from 2018, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Grand River Regulatory Floodplain | Grand River Conservation Authority | 2018 | final |
| Beeney Creek | Credit Valley Conservation Authority | 2013 | final · not public |
| Black Creek | Credit Valley Conservation Authority | 2010 | final · not public |
| West Credit River | Credit Valley Conservation Authority | 2008 | final · not public |
| Shaw's Creek | Credit Valley Conservation Authority | 2007 | final · not public |
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, Erin included, beside 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 Erin (3 of 5), the first dating from the 2000s.
Study dates as the NRCan inventory lists them, one count per study touching Erin.
Flood mapping is shown for Erin 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 Erin $0.018 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.018 per $1,000, Erin’s earthquake risk is about the typical Canadian town’s ($0.030; 0.6 times).
Shaking damage a year per $1,000 of building value
Below the middle in Ontario: Erin’s $0.018 against a median of $0.043; Alexandria has $0.21.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Most of Canada’s 2,611 towns (68%) face more earthquake damage than Erin.
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 loss is to Erin’s buildings alone, from ground shaking; infrastructure and secondary hazards are left out.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
11% of homes tested around Erin are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline. · Area-wide: radon tests, counted over the Wellington-Dufferin-Guelph Health Unit
Erin’s survey area reads 11% over the guideline, well past the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Around Erin, 11% of tests were over 200 Bq/m³ and 2% over 600, against a median of 4% in Ontario.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
More high tests than most: Erin 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 survey sample isn’t a map: any home in Erin can be high, and a three-month test is the only way to know.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Erin
Alerts for Erin 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 Erin to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Hazards in the places around Erin
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Erin | Low | $0.018 | 11% | Yes |
| East Garafraxa 2,976 · 15 km | Low | $0.018 | 11% | Yes |
| Orangeville 33,070 · 17 km | Low | $0.012 | 11% | Yes |
| Georgetown 68,265 · 18 km | Low | $0.025 | 4.1% | Yes |
Among its neighbours Erin has the most fire on record (low); East Garafraxa follows (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Erin faces
What to do about the hazards Erin 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.
- Clear needles and wood nearby.
- Keep a grab-and-go bag ready.
- In smoke, stay in; filter air.
- Has it had a radon test?
- Check the address on the flood map.
- Are flood and wildfire insured?
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 Erin 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 Erin sits in.
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Erin’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 Erin’s.
Questions about flooding and hazards in Erin
How big is the earthquake risk in Erin?
NRCan’s model expects shaking to cost buildings in Erin $0.018 a year for every $1,000 of their value, on average over many years.
Is radon a problem in Erin?
In Health Canada’s survey, 11% of 99 homes tested in Erin’s area were above 200 Bq/m³, though only a test tells you about one house.
How is Erin’s Hazard risk Grade worked out?
Hazard risk gives Erin B, weighing earthquakes and radon and counting wildfire only against it.
Does Erin flood?
Erin’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 Erin at risk of wildfire?
The burned-area record shows next to nothing around Erin (0% within 25 km since 1986), so its band is low.
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).