Photo: P199 · CC BY-SA 3.0A quiet place for hazards: low wildfire, little earthquake risk, and 1.9% of tested homes over the radon guideline in South River’s area
The burned-area map is nearly blank around South River, 0% within 25 km since 1986, 0.000% a year. Earthquake risk in South River is ordinary: NRCan’s model puts building losses at $0.035 a year per $1,000 of value, close to the typical town’s $0.030. Hazard risk gives South River a grade of A−, from earthquakes and radon alone.
What stands out about South River’s hazards
Four national sources, each read for South River: earthquakes, radon, past fires and flood studies.
What South River faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
South River grades A− for hazard risk
Two inputs always count for South River, earthquakes and radon; the third, wildfire, counts only against a town.
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.
Little of the land around South River has burned: 0% within 5 km, 0% within 25 km since 1986
Fires mapped since 1986 around where South River’s residents live, and the fuel next to their homes.
South River burns at 0.000% a year, low against 0.000% for the typical Canadian town.
The closest burn since 1986 lies 21 km from South River’s homes, none within 5 km.
Forest crowds in on South River: 36% of the land within 5 km is forest fuel, more than the 21% 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 872
Fire has taken almost none of the land around South River, as for 639 of the 872 towns in Ontario; Sioux Lookout tops the list 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.
The low band holds 92% of Canada’s 2,610 towns, and South River sits at its very bottom; only 7.5% are 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.
The flood map inventory lists nothing for South River
Flood studies whose area touches South River, from NRCan’s inventory, each linked to its owner.
Canada’s Flood Map Inventory lists no study whose area touches South River, which doesn’t mean it has never been mapped.
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, beside 58% across Canada, but not South River.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood is shown here, never graded: a study says where a map exists, not how many of South River’s homes stand in a flood zone.
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.”
Earthquakes cost buildings in South River $0.035 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.
Earthquake losses in South River, $0.035 per $1,000, are in line with the typical $0.030 (1.2 times).
Shaking damage a year per $1,000 of building value
Neither high nor low in Ontario: South River’s $0.035 sits by the median of $0.043, while Alexandria reaches $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.
South River’s earthquake risk lands near the centre of Canada’s range; 46% of the 2,611 towns are higher.
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 South River’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).
Radon runs low around South River: 1.9% of tested homes over the guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
Radon runs below the typical Canadian town (6.6%) in South River’s area, at 1.9%. Behind radon tests sits data gathered across the North Bay Parry Sound District Health Unit, with South River one part of it.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
South River’s area, at 1.9%, is below the median in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
The quietest radon band, under 5%, holds 37% of Canada’s 2,611 towns and South River; 63% sit 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.
A survey sample isn’t a map: any home in South River 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 South River
Environment and Climate Change Canada issues the weather alerts for South River; 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 South River, 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)
Hazards in the places around South River
The same four hazards for the places next door.
None of the places around has more fire nearby than South River (low); Sundridge comes closest (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what South River faces
What to do about the hazards South River 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?
- Ask the municipality for flood maps.
- Are flood and wildfire insured?
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 South River until then.
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for South River without grading them.
- Wildfire counts one way. Wildfire is read from the national burned-area record around South River’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; South River’s figure is its subdivision’s.
Questions about flooding and hazards in South River
How is South River’s Hazard risk Grade worked out?
Hazard risk gives South River A−, weighing earthquakes and radon and counting wildfire only against it.
How big is the earthquake risk in South River?
Expected earthquake damage in South River comes to $0.035 a year for each $1,000 that buildings are worth.
Does South River flood?
Nothing is listed for South River on the national inventory (0); local maps may still exist with the municipality.
Is radon a problem in South River?
In Health Canada’s survey, 1.9% of 103 homes tested in South River’s area were above 200 Bq/m³, though only a test tells you about one house.
Is South River at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of South River has burned since 1986, the last in 2012, a low band that leaves Risk alone.
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).