Photo: Earth Science and Remote Sensing Unit , Lyndon B. Johnson Space Center · Public domainEarthquake risk in Southern Gulf Islands runs 15 times the typical Canadian town’s: $0.46 per $1,000 a year
The burned-area map is nearly blank around Southern Gulf Islands, 0% within 25 km since 1986, 0.001% a year. Fewer homes than usual carry radon here, 1.8% over the guideline where the typical town has 6.6%. Hazard risk gives Southern Gulf Islands a grade of B−, from earthquakes and radon alone.
What stands out about Southern Gulf Islands’s hazards
Four national sources, each read for Southern Gulf Islands: earthquakes, radon, past fires and flood studies.
What Southern Gulf Islands faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Southern Gulf Islands grades B− for hazard risk
The grade weighs Southern Gulf Islands’ seismic risk and radon equally, and wildfire is one-sided: a high band counts against a town, a low one earns nothing.
Its place: #173 of 254 in British Columbia and #1,760 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Only 55 homes were tested in the survey area, so the radon share is rough. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Southern Gulf Islands: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Southern Gulf Islands’ homes, from the national burned-area record, with the fuel within 5 km.
The land within 25 km of Southern Gulf Islands burns at 0.001% a year on average, the low band; the typical Canadian town: 0.000%.
Since 1986 the nearest fire to Southern Gulf Islands’ homes came within 15 km, never inside 5 km.
Forest crowds in on Southern Gulf Islands: 88% of the land within 5 km is forest fuel, more than the 67% 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 British Columbia · highest of 255
In the lower half in British Columbia: Southern Gulf Islands at 0.001% a year, 239th of 255, far from Oliver’s 0.98%.
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.
Beside 2,610 Canadian towns, Southern Gulf Islands reads low, with 92% of them; only 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.
Southern Gulf Islands is on the flood map inventory: 1 study, by Capital Regional District
What Canada’s Flood Map Inventory lists for Southern Gulf Islands: who studied flooding and where to see their maps.
For Southern Gulf Islands the inventory points to Capital Regional District’s 2021 study, whose map is the one to check.
| Study | By | Year | Status |
|---|---|---|---|
| Capital Regional Coastal Flood Inundation Mapping Project | Capital Regional District | 2021 | final |
Towns with a flood study on file
Mapping in British Columbia reaches 76% of towns, Southern Gulf Islands 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.
Listed, not scored: a flood study proves a map exists, not that Southern Gulf Islands 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.
Earthquakes cost buildings in Southern Gulf Islands $0.46 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
At $0.46 per $1,000, Southern Gulf Islands carries roughly 15.4 times the typical Canadian town’s earthquake risk ($0.030).
Shaking damage a year per $1,000 of building value
Above the middle in British Columbia: Southern Gulf Islands’ $0.46 against a median of $0.36, with Duncan highest at $1.33.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Only 2.8% of Canada’s 2,611 towns expect more shaking damage than Southern Gulf Islands.
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 Southern Gulf Islands’ 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 Southern Gulf Islands: 1.8% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Where the typical Canadian town has 6.6% of homes over the guideline, Southern Gulf Islands’ area has fewer, 1.8%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon around Southern Gulf Islands is ordinary for towns in British Columbia: 1.8%, beside a median of 1.8%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Southern Gulf Islands is in the lowest band, with 37% of Canada’s 2,611 towns: under 5% of tests over the guideline, while 63% have more.
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.
The share describes the area, not a house: in Southern Gulf Islands as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests published for the South Vancouver Island health region, not by town
Weather and fire alerts for Southern Gulf Islands
Alerts for Southern Gulf Islands 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 Southern Gulf Islands 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)
How Southern Gulf Islands’ neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Southern Gulf Islands | Low | $0.46 | 1.8% | Yes |
| Saltspring Island 12,429 · 17 km | Low | $0.42 | 1.8% | Yes |
| North Saanich 12,986 · 19 km | Low | $0.73 | 1.8% | Yes |
| Sidney 13,445 · 19 km | Low | $0.76 | 1.8% | Yes |
The fire record around Saltspring Island is a touch heavier than Southern Gulf Islands’, but the band is the same: low (here low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Southern Gulf Islands faces
What to do about the hazards Southern Gulf Islands 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
- Wildfire counts one way. The wildfire figure is the share of land within 25 km of Southern Gulf Islands’ homes burned each year from 1986 to 2025, past fire rather than a forecast, and it can only lower Risk.
- Flood studies aren’t flood zones. The flood inventory points to maps; it is incomplete and not the official source, so ask the municipality about any street in Southern Gulf Islands.
- 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 Southern Gulf Islands’.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Southern Gulf Islands takes its 2007 health region’s share.
Questions about flooding and hazards in Southern Gulf Islands
Does Southern Gulf Islands flood?
The inventory lists a study touching Southern Gulf Islands; whether a given street floods is on that map, not in the grade.
Is radon a problem in Southern Gulf Islands?
In Health Canada’s survey, 1.8% of 55 homes tested in Southern Gulf Islands’ area were above 200 Bq/m³, though only a test tells you about one house.
How is Southern Gulf Islands’s Hazard risk Grade worked out?
Southern Gulf Islands grades B− for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
How big is the earthquake risk in Southern Gulf Islands?
NRCan’s model expects shaking to cost buildings in Southern Gulf Islands $0.46 a year for every $1,000 of their value, on average over many years.
Is Southern Gulf Islands at risk of wildfire?
Less than most of Canada: 0% of the land within 25 km of Southern Gulf Islands has burned since 1986, the last in 2018, 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).