Photo: 4300streetcar · CC BY 4.0Shaking costs buildings in Port Mann $0.47 a year per $1,000 of value, 16 times the typical town’s
Little of the land around Port Mann has burned: 0.1% within 25 km since 1986, or 0.003% a year. Fewer homes than usual carry radon here, 0% over the guideline where the typical town has 6.6%. Hazard risk gives Port Mann a grade of B; its wildfire band pulls it down.
What stands out about Port Mann’s hazards
Four national sources, each read for Port Mann: earthquakes, radon, past fires and flood studies.
What Port Mann faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Port Mann: B
Seismic risk and radon set Port Mann’s grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #59 of 254 in British Columbia and #1,520 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 70 home tests in the survey area, so a few homes move it. Small fires and grass fires are largely missing from the national burned-area record.
Little of the land around Port Mann has burned: 0% within 5 km, 0.1% within 25 km since 1986
Past fire around Port Mann’s homes, from the national burned-area record, with the fuel within 5 km.
The yearly burn rate around Port Mann is 0.003%, low beside 0.000% for the typical Canadian town.
Fire has stayed at least 13 km from Port Mann’s homes since 1986.
Close to Port Mann there is little to burn (3.6% forest fuel within 5 km), but 28% of the land within 25 km is forest.
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
Some fire is mapped around Port Mann (0.003% a year), but it ranks only 191st of 255 towns in British Columbia; Oliver has 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.
Port Mann is in the low band with 92% of Canada’s 2,610 towns; 7.5% sit in moderate or 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.
2 flood studies cover Port Mann, the newest from City of Coquitlam
What Canada’s Flood Map Inventory lists for Port Mann: who studied flooding and where to see their maps.
City of Coquitlam and others have studied flooding in areas that include Port Mann: 2 studies, the latest from 2017.
| Study | By | Year | Status |
|---|---|---|---|
| Coquitlam, Fraser, Pitt Rivers Floodplain Mapping | City of Coquitlam | 2017 | final |
| Serpentine & Nicomekl River Climate Change Floodplain Review Phase 2 | City of Surrey | 2015 | final |
Towns with a flood study on file
Flood maps are common in British Columbia: 76% of towns have one, against 58% nationally, and Port Mann is among them.
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 Port Mann’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.”
Natural Resources Canada, Canada Flood Map Inventory; links go to each study’s owner.
Earthquakes cost buildings in Port Mann $0.47 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Port Mann’s $0.47 is about 15.7 times the typical town’s $0.030: it sits in one of Canada’s more active seismic zones.
Shaking damage a year per $1,000 of building value
The typical town in British Columbia expects $0.36 a year; Port Mann expects $0.47, and Duncan $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 1.6% of Canada’s 2,611 towns expect more shaking damage than Port Mann.
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).
The loss is to Port Mann’s buildings alone, from ground shaking; infrastructure and secondary hazards are left out.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean). · Area behind the earthquake risk figures: the city of Surrey
0% of homes tested around Port Mann are over the radon guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
A lower share than most: 0% of tested homes around Port Mann, the typical Canadian town 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
The median in British Columbia is 1.8% over 200 Bq/m³; around Port Mann it is 0%.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Under 5% puts Port Mann with 37% of Canada’s 2,611 towns; 63% have more high tests.
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.
Basements, soil and how a house is sealed decide its radon, so in Port Mann only a test can say.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests: one figure for all of the Fraser South health region
Weather and fire alerts for Port Mann
Environment and Climate Change Canada issues the weather alerts for Port Mann; 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 Port Mann, 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 Port Mann’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 |
|---|---|---|---|---|
| Port Mann | Low | $0.47 | 0% | Yes |
| Birdland 10,745 · 1.4 km | Low | $0.47 | 0% | Yes |
| Whalley 52,642 · 2.3 km | Low | $0.47 | 0% | Yes |
| Bridgeview 3,511 · 2.6 km | Low | $0.47 | 0% | Yes |
| Guildford 14,663 · 3.0 km | Low | $0.47 | 0% | None listed |
| Johnston Heights 30,971 · 3.2 km | Low | $0.47 | 0% | Yes |
| Fraser Heights 17,688 · 4.6 km | Low | $0.47 | 0% | Yes |
Nowhere around Port Mann burns more: Birdland, 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 Port Mann faces
Practical steps for Port Mann’s hazards, most pressing first.
- 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
- Flood studies aren’t flood zones. Flood studies cover areas of every size, which is why the page lists them for Port Mann without grading them.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Port Mann’s figure is its subdivision’s.
- Wildfire counts one way. Wildfire is read from the national burned-area record around Port Mann’s homes since 1986, a history of fire that may lower Risk but never raises it.
- 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 Port Mann until then.
Questions about flooding and hazards in Port Mann
Is radon a problem in Port Mann?
0% of the 70 homes Health Canada tested around Port Mann topped the guideline; your own house needs its own test.
Does Port Mann flood?
A flood study covers Port Mann on Canada’s Flood Map Inventory; open the owner’s map to check a street, since flood isn’t graded.
How is Port Mann’s Hazard risk Grade worked out?
Port Mann’s Hazard risk grade is B, built on earthquakes and radon with a one-sided wildfire input.
Is Port Mann at risk of wildfire?
Not much by Canadian standards: Port Mann’s band is low, with 0.1% of the land within 25 km burned since 1986 (last in 2022), so wildfire doesn’t change its grade.
How big is the earthquake risk in Port Mann?
In NRCan’s seismic model, Port Mann’s buildings lose $0.47 per $1,000 of value in an average year.
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).