Photo: Meantimeus · Public domainA flood study covers Grand Manan: 1 on the national inventory, the newest from Service New Brunswick - GeoNB
Fire has left almost no mark near Grand Manan: 0% of the land within 25 km since 1986, 0.000% a year. Seismic risk runs high: $0.13 of expected damage per $1,000 of buildings a year, the typical town $0.030. In Health Canada’s survey, 11% of homes tested in the area exceeded 200 Bq/m³ (6.6% typical). Hazard risk gives Grand Manan a grade of C−, from earthquakes and radon alone.
What stands out about Grand Manan’s hazards
For Grand Manan, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Grand Manan faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Grand Manan grades C− for hazard risk
For Grand Manan, Risk will be the average of earthquakes and radon, with wildfire added only if it makes the average worse.
Its place: #44 of 60 in New Brunswick and #2,412 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The burned-area record misses fires under about 10 ha and most grass and farm fires.
Wildfire is rare near Grand Manan: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Grand Manan’s residents live, and the fuel next to their homes.
Around Grand Manan fire takes 0.000% of the land in a typical year, the typical Canadian town 0.000%, which is low.
About as much forest grows next to Grand Manan’s homes (92% within 5 km) as across 25 km (92%).
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 New Brunswick · highest of 60
Of the 60 towns in New Brunswick, 15 have a burn rate that rounds to zero, Grand Manan among them; Tracadie leads at 0.28% a year.
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.
Most of the country’s 2,610 towns are low-band (92%, against 7.5% above); around Grand Manan, burning rounds to zero.
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.
Grand Manan is on the flood map inventory: 1 study, by Service New Brunswick - GeoNB
Flood studies whose area touches Grand Manan, from NRCan’s inventory, each linked to its owner.
Service New Brunswick - GeoNB studied flooding in an area that includes Grand Manan (2020); open its map to see which streets lie in a flood zone.
| Study | By | Year | Status |
|---|---|---|---|
| Inland Flood Mapping in New Brunswick and Updated Sea-Level Rise and Flooding Estimates for New Brunswick Coastal Sections 2020 | Service New Brunswick - GeoNB | 2020 | final |
Towns with a flood study on file
Flood maps are common in New Brunswick: 93% of towns have one, against 58% nationally, and Grand Manan is among them.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood studies don’t enter the grade; they are listed so you can open the official map for Grand Manan.
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 Grand Manan $0.13 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.
Roughly 4.3 times the typical $0.030: Grand Manan’s $0.13 marks real seismic exposure.
Shaking damage a year per $1,000 of building value
Earthquake risk in New Brunswick peaks in St. Stephen ($0.16); Grand Manan, at $0.13, sits above the median of $0.036.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Grand Manan sits above most of Canada’s 2,611 towns on earthquake risk; 22% 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).
What a quake does after the shaking, fire, landslides, tsunami, falls outside NRCan’s figure for Grand Manan.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
11% of homes tested around Grand Manan are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
A higher share than most: 11% of tested homes around Grand Manan, the typical Canadian town 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Grand Manan’s area, at 11%, is below the median in New Brunswick (20%), though 1% of its tests passed 600 Bq/m³.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
More high tests than most: Grand Manan sits in a band that only 22% of Canada’s 2,611 towns share, with 4.6% 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.
Whatever Grand Manan’s area share, the reading that matters is your own home’s, over a winter.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests: one figure for all of the Region 2 health region
Where to get warnings in Grand Manan
Alerts for Grand Manan 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. |
Evacuation orders for Grand Manan come from the municipality or the province, while CWFIS maps fire danger every day.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Grand Manan faces
Practical steps for Grand Manan’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
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Grand Manan is its health region’s, the survey’s design unit.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Grand Manan’s included.
- Flood studies aren’t flood zones. NRCan’s inventory says where flood mapping exists, not where water goes; the map’s owner is the authority for Grand Manan.
- 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 Grand Manan.
Questions about flooding and hazards in Grand Manan
How is Grand Manan’s Hazard risk Grade worked out?
Grand Manan grades C− for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Is Grand Manan at risk of wildfire?
Very little by the national record: Grand Manan’s band is low, with 0% of the land within 25 km burned since 1986, so wildfire doesn’t change its grade.
How big is the earthquake risk in Grand Manan?
Expected earthquake damage in Grand Manan comes to $0.13 a year for each $1,000 that buildings are worth.
Is radon a problem in Grand Manan?
The area’s survey found 11% of 101 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Grand Manan.
Does Grand Manan flood?
There is flood mapping for Grand Manan on the national inventory, each study linked to its owner’s map, none of them graded.
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).