Photo: Globalphotobank · CC BY-SA 4.0Williams Lake faces more hazards than 97% of Canadian towns
Wildfire is a real hazard for Williams Lake: 16% of the land within 25 km has burned since 1986, 0.45% a year, in the high band. Earthquakes matter little: NRCan’s model puts building losses at $0.011 a year per $1,000 of value, against $0.030 for the typical town. Radon is about average around Williams Lake: 6.4% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Williams Lake grades D− for hazard risk, with wildfire counted against it.
What stands out about Williams Lake’s hazards
For Williams Lake, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Williams Lake faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Williams Lake: D−
For Williams Lake, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #242 of 254 in British Columbia and #2,564 of 2,589 Canadian towns.
How sure: The seismic figure is a long-run average from NRCan’s model, not a prediction. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Fire country: 16% of the land within 25 km of Williams Lake has burned since 1986, 3% within 5 km
Past fire around Williams Lake’s homes, from the national burned-area record, with the fuel within 5 km.
The yearly burn rate around Williams Lake is 0.45%, against 0.000% for the typical Canadian town: the high band.
Within 5 km of Williams Lake, 57% of the land is forest fuel; widen the ring to 25 km and it is 64%.
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
Williams Lake ranks 13th of the 255 towns in British Columbia for burn rate, at 0.45% a year; Oliver leads with 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.
Just 1.9% of Canada’s 2,610 towns burn fast enough for the high band where Williams Lake sits; 0.2% 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.
A flood study covers Williams Lake, from Ministry of Environment and Climate Change Strategy: 1 on the inventory
What Canada’s Flood Map Inventory lists for Williams Lake: who studied flooding and where to see their maps.
For Williams Lake the inventory points to Ministry of Environment and Climate Change Strategy’s 1990 study, whose map is the one to check.
| Study | By | Year | Status |
|---|---|---|---|
| Williams Lake Floodplain Mapping | Ministry of Environment and Climate Change Strategy | 1990 | final |
Towns with a flood study on file
Mapping in British Columbia reaches 76% of towns, Williams Lake 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 Williams Lake 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 Williams Lake just $0.011 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Shaking costs the typical town $0.030 a year; in Williams Lake it is only $0.011, 0.4 times as much.
Shaking damage a year per $1,000 of building value
Below the middle in British Columbia: Williams Lake’s $0.011 against a median of $0.36; Duncan has $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.
85% of Canada’s 2,611 towns expect more shaking damage than Williams Lake.
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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Williams Lake.
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 Williams Lake: 6.4% over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
6.4% of tested homes around Williams Lake were over the guideline, much like the typical Canadian town at 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Williams Lake than in most towns in British Columbia: 6.4% against 1.8%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Radon tops the guideline in a modest share of homes around Williams Lake, a band holding 37% of Canada’s 2,611 towns; 26% rank 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.
Neighbouring homes in Williams Lake can differ a lot; only a long-term test tells you about yours.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Not measured by town: radon tests (the Thompson/Cariboo health region)
Where to get warnings in Williams Lake
Alerts for Williams Lake 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 Williams Lake to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Williams Lake’s neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Williams Lake | High | $0.011 | 6.4% | Yes |
| Electoral Area D, Cariboo 3,057 · 6.4 km | High | $0.011 | 6.4% | Yes |
| Electoral Area E, Cariboo 4,242 · 6.8 km | High | $0.016 | 6.4% | Yes |
Electoral Area E, Cariboo (high) has the heaviest fire record of Williams Lake’s neighbours, and Williams Lake (high) matches or beats it.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Williams Lake faces
Practical steps for Williams Lake’s hazards, most pressing first.
- Clear needles and wood nearby.
- Keep a grab-and-go bag ready.
- In smoke, stay in; filter air.
- 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.
- Has it had a radon test?
- Check the address on the flood map.
- How close is the forest edge?
- 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 Williams Lake until then.
- Wildfire counts one way. For Williams Lake, wildfire means how much nearby land burned in the past forty years, a one-way input that can pull Risk down and nothing more.
- Earthquakes are modelled. Seismic risk is NRCan’s model of yearly building losses from shaking, averaged over many years and given for Williams Lake’s census subdivision (a neighbourhood shows its city’s).
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Williams Lake without grading them.
Questions about flooding and hazards in Williams Lake
Is radon a problem in Williams Lake?
The area’s survey found 6.4% of 109 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Williams Lake.
Does Williams Lake flood?
A flood study covers Williams Lake on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
How is Williams Lake’s Hazard risk Grade worked out?
Hazard risk gives Williams Lake D−, weighing earthquakes and radon and counting wildfire only against it.
How big is the earthquake risk in Williams Lake?
In NRCan’s seismic model, Williams Lake’s buildings lose $0.011 per $1,000 of value in an average year.
Is Williams Lake at risk of wildfire?
Wildfire is Williams Lake’s main hazard, band high: 16% of the land within 25 km burned between 1986 and 2025.
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).