Photo: P199 · CC BY-SA 3.0Rideau Lakes faces more hazards than 89% of Canadian towns
Wildfire barely registers for Rideau Lakes, at 0% of the land within 25 km since 1986 (0.000% a year). Seismic risk in Rideau Lakes sits near the middle: $0.059 of expected damage per $1,000 of buildings a year, the typical town $0.030. Radon is higher than usual: 19% of tested homes in the survey area topped the guideline, against 6.6% for the typical town. Hazard risk gives Rideau Lakes a grade of D, from earthquakes and radon alone.
What stands out about Rideau Lakes’s hazards
For Rideau Lakes, from NRCan’s seismic model, Health Canada’s radon survey, the national burned-area record and the flood map inventory.
What Rideau Lakes faces
Each hazard against its own yardstick; meters run from low to high on that yardstick.
Wildfire
Earthquakes
Radon
Flood study
Rideau Lakes grades D for hazard risk
Seismic risk and radon set Rideau Lakes’ grade, wildfire can drag it down, and flood mapping stays out of it.
Its place: #848 of 866 in Ontario and #2,462 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 Rideau Lakes: 0% of the land within 25 km burned since 1986, 0% within 5 km
Past fire around Rideau Lakes’ homes, from the national burned-area record, with the fuel within 5 km.
Low by Canadian standards: 0.000% of the land a year around Rideau Lakes, 0.000% for the typical Canadian town.
Forest fuel rises from 4.6% within 5 km of Rideau Lakes to 9% within 25 km: the fuel lies away from homes.
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
Fire has taken almost none of the land around Rideau Lakes, as for 638 of the 871 towns in Ontario; Sioux Lookout tops the list 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 Rideau Lakes, 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.
Rideau Lakes is on the flood map inventory: 5 studies, latest by Rideau Valley Conservation Authority
What Canada’s Flood Map Inventory lists for Rideau Lakes: who studied flooding and where to see their maps.
Rideau Valley Conservation Authority and others have studied flooding in areas that include Rideau Lakes: 5 studies, the latest from 2016.
| Study | By | Year | Status |
|---|---|---|---|
| Otter and Hutton Creeks | Rideau Valley Conservation Authority | 2016 | final |
| Rideau River, Poonamalie Dam to Smith Falls | Rideau Valley Conservation Authority | 2010 | final |
| Rideau River Tributaries, Smiths Falls to Kars | Rideau Valley Conservation Authority | 1983 | final |
| Rideau River Floodline Mapping, Smiths Falls to Poonamalie | Rideau Valley Conservation Authority | 1979 | final |
| Rideau River, Smiths Falls to Kars | Rideau Valley Conservation Authority | 1976 | final |
Towns with a flood study on file
69% of towns in Ontario have a flood study, more than Canada’s 58%; Rideau Lakes has one too.
NRCan Canada Flood Map Inventory: a study footprint touching the town’s boundary; towns of 2,500 people or more.
Flood mapping around Rideau Lakes has come in steps: 5 studies from the 1970s to the 2010s.
Study dates as the NRCan inventory lists them, one count per study touching Rideau Lakes.
Flood is shown here, never graded: a study says where a map exists, not how many of Rideau Lakes’ 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 Rideau Lakes $0.059 per $1,000 a year
Expected yearly building losses from earthquakes, from Natural Resources Canada’s model.
Earthquake losses in Rideau Lakes, $0.059 per $1,000, are in line with the typical $0.030 (2 times).
Shaking damage a year per $1,000 of building value
The typical town in Ontario expects $0.043 a year; Rideau Lakes expects $0.059, and Alexandria $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.
In the upper part of Canada’s range: 30% of its 2,611 towns expect more damage than Rideau Lakes.
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 Rideau Lakes.
Natural Resources Canada, Canada’s Seismic Risk Model (2022), by census subdivision (2016 boundaries; a few 2021 subdivisions take their residents’ mean).
Test for radon in Rideau Lakes: 19% of area homes were over the guideline
Long-term radon tests in homes across the survey area, against Health Canada’s guideline.
Rideau Lakes’ survey area reads 19% over the guideline, well past the typical Canadian town’s 6.6%.
Tested homes over 200 Bq/m³
Over 600 Bq/m³
Radon runs higher around Rideau Lakes than in most towns in Ontario: 19% over the guideline (4% is typical), 1.9% over 600.
Health Canada radon survey (2009–2011), by 2007 health region; medians of towns of 2,500 people or more.
Rideau Lakes is in the 10–20% band, with 22% of Canada’s 2,611 towns; only 4.6% are higher.
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 Rideau Lakes’ 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 Leeds, Grenville and Lanark District Health Unit
Where to get warnings in Rideau Lakes
Environment and Climate Change Canada issues the weather alerts for Rideau Lakes; 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. |
Smoke and fire warnings for Rideau Lakes come through Environment Canada and Alert Ready; the fire map is CWFIS’s.
Weather alerts (ECCC) · Alert Ready · Fire danger and active fires (CWFIS)
How Rideau Lakes’ neighbours compare on hazards
Wildfire band, earthquake risk, radon and flood studies for each place nearby.
| Town | Wildfire | Quake $/1,000 | Radon | Flood study |
|---|---|---|---|---|
| Rideau Lakes | Low | $0.059 | 19% | Yes |
| Athens 3,078 · 18 km | Low | $0.067 | 19% | None listed |
The neighbour with the most fire is Athens (low), still no more than Rideau Lakes (low).
Radon is the survey area’s figure, so neighbours in one area share it.
Get ready for what Rideau Lakes faces
Practical steps for Rideau Lakes’ 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
- 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 Rideau Lakes.
- Earthquakes are modelled. The earthquake figure is an expected loss, not a forecast, worked out by NRCan for each census subdivision, Rideau Lakes’ included.
- Radon is a survey. Health Canada’s survey tested some 14,000 homes over three months; until postal-area boundaries are loaded, Rideau Lakes takes its 2007 health region’s share.
- 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 Rideau Lakes.
Questions about flooding and hazards in Rideau Lakes
Is Rideau Lakes at risk of wildfire?
Hardly at all on record: 0% of the land within 25 km of Rideau Lakes since 1986, a low band, though small grass fires aren’t mapped.
How is Rideau Lakes’s Hazard risk Grade worked out?
Rideau Lakes grades D for hazard risk, from earthquakes and radon, with wildfire counted only where it lowers the grade.
Does Rideau Lakes flood?
The inventory lists a study touching Rideau Lakes; whether a given street floods is on that map, not in the grade.
Is radon a problem in Rideau Lakes?
The area’s survey found 19% of 108 tested homes above Health Canada’s guideline, so a three-month test is worth doing in Rideau Lakes.
How big is the earthquake risk in Rideau Lakes?
In NRCan’s seismic model, Rideau Lakes’ buildings lose $0.059 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).