Photo: Earth Science and Remote Sensing Unit , Lyndon B. Johnson Space Center · Public domain35% of homes tested in Riverdale’s area are above the radon guideline
Burn scars are few around Riverdale, with 0% of the land within 25 km touched by fire since 1986 (0.000% a year). Earthquakes matter little: NRCan’s model puts building losses at $0.005 a year per $1,000 of value, against $0.030 for the typical town. Hazard risk gives Riverdale a grade of B−, from earthquakes and radon alone.
What stands out about Riverdale’s hazards
Four national sources, each read for Riverdale: earthquakes, radon, past fires and flood studies.
What Riverdale faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Hazard risk in Riverdale: B−
Earthquake risk and radon make Riverdale’s grade; wildfire can only lower it, never raise it, and flood studies are listed but not scored.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. Small fires and grass fires are largely missing from the national burned-area record.
Wildfire is rare near Riverdale: 0% of the land within 25 km burned since 1986, 0.1% within 5 km
Past fire around Riverdale’s homes, from the national burned-area record, with the fuel within 5 km.
In a typical year 0.000% of the land near Riverdale burns; the typical Canadian town sees 0.000%, and both are low.
Land that isn’t forest covers nearly all the ground around Riverdale: forest fuel is 0% within 5 km and 0% 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 Manitoba · highest of 190
Fire has taken almost none of the land around Riverdale, as for 61 of the 190 towns in Manitoba; Flin Flon (Part) tops the list at 1.68%.
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.
Only 7.5% of Canada’s 2,610 towns are above the low band, which holds 92%; Riverdale, at a rounded zero, is far from them.
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.
Riverdale is on the flood map inventory: 2 studies, latest by Hydrologic Forecasting and Water Management Branch of Manitoba Transporation and Infrastructure
What Canada’s Flood Map Inventory lists for Riverdale: who studied flooding and where to see their maps.
2 studies on the inventory touch Riverdale, the newest Hydrologic Forecasting and Water Management Branch of Manitoba Transporation and Infrastructure ’s from 2025, and their areas can be large, so they say maps exist, not that the town floods.
| Study | By | Year | Status |
|---|---|---|---|
| Hydrodynamic Modelling Study for the Upper Assiniboine River: Mapped communities-St. Lazarre and Brandon | Hydrologic Forecasting and Water Management Branch of Manitoba Transporation and Infrastructure | 2025 | final · not public |
| Hydrodynamic Modelling of Lower Little Saskatchewan: Mapped communities: Minnedosa, Rapid City, Rivers | Hydrologic Forecasting and Water Management Branch of Manitoba Transporation and Infrastructure | 2025 | final · not public |
Towns with a flood study on file
Mapping in Manitoba reaches 18% of towns, Riverdale among them, below the 58% across Canada.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping is shown for Riverdale to be opened and checked, never turned into a grade.
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.
Low seismic risk in Riverdale: $0.005 per $1,000 of buildings a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Shaking costs the typical town $0.030 a year; in Riverdale it is only $0.005, 0.2 times as much.
Shaking damage a year per $1,000 of building value
The median in Manitoba is $0.006; Riverdale, at $0.005, is right beside it, and Virden tops the list at $0.007.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
Nearly every one of Canada’s 2,611 towns (96%) expects more shaking damage than Riverdale.
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 Riverdale’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 high around Riverdale: 35% of tested homes over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
At 35% over the guideline, the area around Riverdale beats the typical Canadian town’s 6.6%. Riverdale doesn’t get its own radon tests figures; the ones here come from the Assiniboine health region.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Riverdale’s area, at 35%, is above the median in Manitoba (12%), and 1.8% 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.
No band is higher: Riverdale is among the 1.5% of Canada’s towns with 30% or more of tests over 200 Bq/m³.
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 Riverdale as anywhere, test to be sure.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011).
Weather and fire alerts for Riverdale
Alerts for Riverdale 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 Riverdale to phones; CWFIS shows the day’s fire danger.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
Get ready for what Riverdale faces
Practical steps for Riverdale’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.
- Clear needles and wood nearby.
- Keep a grab-and-go bag ready.
- In smoke, stay in; filter air.
- Has it had a radon test?
- Check the address on the flood map.
- Are flood and wildfire insured?
What this data can and can’t tell you
- Wildfire counts one way. Wildfire is read from the national burned-area record around Riverdale’s homes since 1986, a history of fire that may lower Risk but never raises it.
- Radon is a survey. About 14,000 homes were tested across Canada in 2009–2011, and the share over the guideline for Riverdale is its health region’s, the survey’s design unit.
- Earthquakes are modelled. NRCan models what earthquakes would cost buildings each year on average, subdivision by subdivision; Riverdale’s figure is its subdivision’s.
- 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 Riverdale.
Questions about flooding and hazards in Riverdale
Is radon a problem in Riverdale?
The area’s survey found 35% of 110 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Riverdale.
How big is the earthquake risk in Riverdale?
In NRCan’s seismic model, Riverdale’s buildings lose $0.005 per $1,000 of value in an average year.
How is Riverdale’s Hazard risk Grade worked out?
Hazard risk gives Riverdale B−, weighing earthquakes and radon and counting wildfire only against it.
Does Riverdale flood?
There is flood mapping for Riverdale on the national inventory, each study linked to its owner’s map, none of them graded.
Is Riverdale at risk of wildfire?
Some, but Riverdale’s low band (0% of nearby land burned since 1986, latest 2000) is short of the level that counts.
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).