A flood study covers Alta Vista: 1 on the national inventory, the newest from Rideau Valley Conservation Authority
Around Alta Vista, wildfire is practically absent from the record: 0% within 25 km since 1986, 0.000% a year. Shaking is a bigger worry than in most places, at $0.15 a year per $1,000 of building value ($0.030 typical). In Health Canada’s survey, 6.2% of homes tested in Alta Vista’s area exceeded 200 Bq/m³, close to the typical 6.6%. Alta Vista grades C+ for hazard risk; wildfire is low here, so it earns no credit.
What stands out about Alta Vista’s hazards
For Alta Vista, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Alta Vista faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Alta Vista: C+
Two inputs always count for Alta Vista, earthquakes and radon; the third, wildfire, counts only against a town.
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.
Little of the land around Alta Vista has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where Alta Vista’s residents live, and the fuel next to their homes.
Fire claims 0.000% of the land around Alta Vista each year, a low band, with the typical Canadian town at 0.000%.
Nothing inside 5 km of Alta Vista’s homes has burned since 1986, and the nearest scar is 22 km off.
Forest fuel rises from 0.5% within 5 km of Alta Vista to 7.1% within 25 km: the fuel lies away from homes.
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
Little or nothing burns around Alta Vista in a typical year; 638 of the 871 towns in Ontario share that, and Sioux Lookout leads 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.
Only 7.5% of Canada’s 2,610 towns are above the low band, which holds 92%; Alta Vista, at a rounded zero, is far from them.
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.
Rideau Valley Conservation Authority has mapped flooding for Alta Vista (1 study)
Flood studies whose area touches Alta Vista, from NRCan’s inventory, each linked to its owner.
One study on the inventory touches Alta Vista, Rideau Valley Conservation Authority’s from 2016, and its area can be large, so it says a map exists, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Rideau River, Hogs Back to Rideau Falls | Rideau Valley Conservation Authority | 2016 | final |
Towns with a flood study on file
Its flood study puts Alta Vista with 69% of towns in Ontario; Canada’s share is 58%.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Nothing here counts toward Risk; the studies are pointers to the maps their owners keep for Alta Vista.
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 Alta Vista $0.15 per $1,000 a year
NRCan’s seismic risk model: the damage shaking is expected to do to buildings each year, on average over many years.
At $0.15 per $1,000, Alta Vista carries roughly 5 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Earthquake risk in Ontario peaks in Alexandria ($0.21); Alta Vista, at $0.15, sits above the median of $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.
More earthquake risk than most: only 15% of Canada’s 2,611 towns are above Alta Vista.
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).
Only shaking damage to buildings in Alta Vista is counted; landslides, liquefaction, tsunami and fire after a quake aren’t.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Earthquake risk: the city of Ottawa
6.2% of homes tested around Alta Vista are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Near the middle for radon: Alta Vista’s area 6.2%, the typical Canadian town 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Alta Vista than in most towns in Ontario: 6.2% against 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 Alta Vista’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 Alta Vista 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). · Area behind the radon tests figures: the City of Ottawa Health Unit
Where to get warnings in Alta Vista
Environment and Climate Change Canada issues the weather alerts for Alta Vista; 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. |
For fires near Alta Vista, the national fire information system maps danger and active fires daily; local authorities give any evacuation order.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Alta Vista’s neighbours compare on hazards
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Alta Vista | Low | $0.15 | 6.2% | Yes |
| Billings Bridge - Heron Park 5,370 · 1.1 km | Low | $0.15 | 6.2% | Yes |
| Old Ottawa South 6,704 · 1.5 km | Low | $0.15 | 6.2% | Yes |
| Playfair Park - Guildwood Estates 6,186 · 1.7 km | Low | $0.15 | 6.2% | None listed |
| Ledbury-Heron Gate-Ridgemont 15,610 · 2.1 km | Low | $0.15 | 6.2% | None listed |
| Riverview 14,030 · 2.4 km | Low | $0.15 | 6.2% | Yes |
| Elmvale - Canterbury 8,149 · 2.6 km | Low | $0.15 | 6.2% | None listed |
None of the places around has more fire nearby than Alta Vista (low); Billings Bridge - Heron Park comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Alta Vista faces
What to do about the hazards Alta Vista 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
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Alta Vista’s included.
- 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 Alta Vista.
- 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 Alta Vista 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 Alta Vista sits in.
Questions about flooding and hazards in Alta Vista
Is Alta Vista at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Alta Vista has burned since 1986, the last in 2014, a low band that leaves Risk alone.
How is Alta Vista’s Hazard risk Grade worked out?
Alta Vista grades C+ for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is radon a problem in Alta Vista?
In Health Canada’s survey, 6.2% of 64 homes tested in Alta Vista’s area were above 200 Bq/m³, though only a test tells you about one house.
Does Alta Vista flood?
Alta Vista’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 Alta Vista?
About $0.15 a year per $1,000 of building value, NRCan’s long-run expectation for Alta Vista.
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).