Chapman Mills is on Canada’s flood inventory: 2 listed, led by Rideau Valley Conservation Authority
The national fire record shows next to nothing around Chapman Mills, 0% of the land within 25 km since 1986 (0.000% a year). Seismic risk runs high: $0.15 of expected damage per $1,000 of buildings a year, the typical town $0.030. Radon around Chapman Mills is ordinary for Canada: 6.2% of tested homes over the guideline (6.6% typical). Hazard risk gives Chapman Mills a grade of C+, from earthquakes and radon alone.
What stands out about Chapman Mills’s hazards
Four national sources, each read for Chapman Mills: earthquakes, radon, past fires and flood studies.
What Chapman Mills faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Chapman Mills grades C+ for hazard risk
Two inputs always count for Chapman Mills, earthquakes and radon; the third, wildfire, counts only against a town.
Its place: #703 of 866 in Ontario and #1,894 of 2,589 Canadian towns.
How sure: Earthquake losses are a model’s expectation over many years, not a forecast for any one. The radon share rests on 64 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.
Wildfire is rare near Chapman Mills: 0% of the land within 25 km burned since 1986, 0% within 5 km
Fires mapped since 1986 around where Chapman Mills’ residents live, and the fuel next to their homes.
The yearly burn rate around Chapman Mills is 0.000%, low beside 0.000% for the typical Canadian town.
Close to Chapman Mills there is little to burn (0.9% forest fuel within 5 km), but 8.9% 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 Ontario · highest of 871
Little or nothing burns around Chapman Mills in a typical year; 638 of the 871 towns in Ontario share that, and Sioux Lookout leads at 0.16%.
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 Chapman Mills, 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.
2 flood studies cover Chapman Mills, the newest from Rideau Valley Conservation Authority
Flood studies whose area touches Chapman Mills, from NRCan’s inventory, each linked to its owner.
Rideau Valley Conservation Authority and others have studied flooding in areas that include Chapman Mills: 2 studies, the latest from 2017.
| Study | By | Year | Status |
|---|---|---|---|
| Rideau River, Hogs Back to Kars | Rideau Valley Conservation Authority | 2017 | final |
| Jock River | Rideau Valley Conservation Authority | 2005 | final |
Towns with a flood study on file
Mapping in Ontario reaches 69% of towns, Chapman Mills 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.
The 2 studies touching Chapman Mills are spread over time, from the 2000s to the 2010s.
Study dates as the NRCan inventory lists them, one count per study touching Chapman Mills.
Flood is shown here, never graded: a study says where a map exists, not how many of Chapman Mills’ 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 Chapman Mills $0.15 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.
The typical town loses $0.030 a year to shaking; Chapman Mills loses $0.15, 5 times as much.
Figures for earthquake risk are published for the city of Ottawa as a whole, not for Chapman Mills alone.
Shaking damage a year per $1,000 of building value
Above the middle in Ontario: Chapman Mills’ $0.15 against a median of $0.043, with Alexandria highest at $0.21.
NRCan seismic risk model (2022): mean yearly building loss per $1,000 of value; medians of towns of 2,500 people or more.
15% of Canada’s 2,611 towns expect more shaking damage than Chapman Mills, which places it in the upper third.
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 Chapman Mills’ 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).
6.2% of homes tested around Chapman Mills are over the radon guideline
Health Canada’s survey of long-term home tests: the share above the 200 Bq/m³ guideline.
The survey area of Chapman Mills reads 6.2%, a shade from the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Chapman Mills’ area, at 6.2%, is above the median in Ontario (4%).
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
26% of Canada’s 2,611 towns have more homes over 200 Bq/m³ than Chapman Mills’ 5–10% band, which holds 37%.
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.
One home in Chapman Mills can be high while next door is low; a three-month test settles it.
Health Canada, Cross-Canada Survey of Radon Concentrations in Homes (2009–2011). · Radon tests: one figure for all of the City of Ottawa Health Unit
Weather and fire alerts for Chapman Mills
Environment and Climate Change Canada issues the weather alerts for Chapman Mills; 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 Chapman Mills, 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)
Hazards in the places around Chapman Mills
The same four hazards for the places next door.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Chapman Mills | Low | $0.15 | 6.2% | Yes |
| Old Barrhaven East 23,585 · 1.9 km | Low | $0.15 | 6.2% | None listed |
| Rideaucrest - Davidson Heights 13,998 · 2.0 km | Low | $0.15 | 6.2% | Yes |
| Stonebridge - Half Moon Bay 28,714 · 2.3 km | Low | $0.15 | 6.2% | Yes |
| Riverside South - Leitrim 19,802 · 3.2 km | Low | $0.15 | 6.2% | Yes |
| Old Barrhaven West 22,012 · 3.5 km | Low | $0.15 | 6.2% | Yes |
| Manotick 8,770 · 6.2 km | Low | $0.15 | 6.2% | Yes |
Fire is no heavier anywhere nearby than around Chapman Mills (low), with Old Barrhaven East next at low.
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Chapman Mills faces
What to do about the hazards Chapman Mills 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 Chapman Mills’ 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 Chapman Mills.
- 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 Chapman Mills’.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Chapman Mills takes its 2007 health region’s share.
Questions about flooding and hazards in Chapman Mills
Is Chapman Mills at risk of wildfire?
No meaningful wildfire history near Chapman Mills: 0% of nearby land since 1986, band low.
Is radon a problem in Chapman Mills?
Around Chapman Mills, 64 survey homes were tested and 6.2% came in over 200 Bq/m³, a guide to the area, not to any one home.
How is Chapman Mills’s Hazard risk Grade worked out?
Hazard risk gives Chapman Mills C+, weighing earthquakes and radon and counting wildfire only against it.
Does Chapman Mills flood?
The inventory lists a study touching Chapman Mills; whether a given street floods is on that map, not in the grade.
How big is the earthquake risk in Chapman Mills?
Expected earthquake damage in Chapman Mills comes to $0.15 a year for each $1,000 that buildings are worth.
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).