Photo: P199 · CC BY-SA 3.0Flood mapping exists for Greely: 1 on record, latest by South Nation Conservation
No wildfire is mapped within 25 km of Greely’s homes since 1986 (0% of the land, 0.000% a year). Earthquakes add more: NRCan’s model puts building losses at $0.15 a year per $1,000 of value, against $0.030 for the typical town. About as many homes carry radon around Greely as elsewhere, 6.2% over the guideline where the typical town has 6.6%. Greely grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Greely’s hazards
For Greely, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Greely faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Greely grades C+ for hazard risk
The grade weighs Greely’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: #703 of 866 in Ontario and #1,894 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The radon share rests on 64 home tests in the survey area, so a few homes move it. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Few fires near Greely: 0% within 5 km, 0% within 25 km
Fires mapped since 1986 around where Greely’s residents live, and the fuel next to their homes.
The land within 25 km of Greely burns at 0.000% a year on average, the low band; the typical Canadian town: 0.000%.
7.7% of the land within 5 km of Greely is forest fuel, close to the 4% 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
Of the 871 towns in Ontario, 638 have a burn rate that rounds to zero, Greely among them; Sioux Lookout leads at 0.16% a year.
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.
Greely 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.
South Nation Conservation has mapped flooding for Greely (1 study)
Flood studies whose area touches Greely, from NRCan’s inventory, each linked to its owner.
For Greely the inventory points to South Nation Conservation’s 2025 study, whose map is the one to check.
| Study | By | Year | Status |
|---|---|---|---|
| Delineating Flood Hazard and Associated Impacts in the Quaile Creek Watershed | South Nation Conservation | 2025 | final · not public |
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Greely has one too.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Listed, not scored: a flood study proves a map exists, not that Greely floods.
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 Greely: $0.15 per $1,000 of buildings a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
The typical town loses $0.030 a year to shaking; Greely loses $0.15, 5 times as much.
Behind earthquake risk sits data gathered across the city of Ottawa, with Greely one part of it.
Shaking damage a year per $1,000 of building value
Above the middle in Ontario: Greely’s $0.15 against a median of $0.043, with Alexandria highest at $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.
More earthquake risk than most: only 15% of Canada’s 2,611 towns are above Greely.
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 Greely 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).
Radon about average around Greely: 6.2% over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline. · Measured across the City of Ottawa Health Unit: radon tests
At 6.2% over the guideline, the area around Greely is about level with the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Greely’s area, at 6.2%, is above the median in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
26% of Canada’s 2,611 towns have more homes over 200 Bq/m³ than Greely’s 5–10% band, which holds 37%.
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 Greely 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 Greely
Alerts for Greely 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 Greely 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)
Hazards in the places around Greely
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Greely | Low | $0.15 | 6.2% | Yes |
| Manotick 8,770 · 7.4 km | Low | $0.15 | 6.2% | Yes |
| Findlay Creek 14,089 · 7.4 km | Low | $0.15 | 6.2% | None listed |
| Riverside South - Leitrim 19,802 · 7.9 km | Low | $0.15 | 6.2% | Yes |
| Metcalfe 5,434 · 9.9 km | Low | $0.15 | 6.2% | Yes |
| Rideaucrest - Davidson Heights 13,998 · 10 km | Low | $0.15 | 6.2% | Yes |
| Chapman Mills 12,075 · 11 km | Low | $0.15 | 6.2% | Yes |
Nowhere around Greely burns more: Manotick, the closest rival, is low to its low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Greely faces
What to do about the hazards Greely 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
- Radon is a survey. Radon figures pool the survey’s home tests by area: postal areas once their boundaries arrive, the 2007 health region around Greely until then.
- 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 Greely.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Greely without grading them.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Greely’s included.
Questions about flooding and hazards in Greely
How big is the earthquake risk in Greely?
Expected earthquake damage in Greely comes to $0.15 a year for each $1,000 that buildings are worth.
How is Greely’s Hazard risk Grade worked out?
Greely grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does Greely flood?
A flood study covers Greely on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
Is radon a problem in Greely?
Around Greely, 64 survey homes were tested and 6.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
Is Greely at risk of wildfire?
No meaningful wildfire history near Greely: 0% of nearby land since 1986, band 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).