Big Barnum Lake
Haliburton, OntarioView mapDirections
Ontario MECP publishes the water-quality measurements for Big Barnum Lake. Here is what has been measured.
- 34 ft max depth
Big Barnum Lake in Haliburton, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 6 m visibility. Phosphorus: 5.3 µg/L.
Stays via Stay22
Stays near Big Barnum Lake
Compare lakeside cabins, hotels, and vacation rentals near Big Barnum Lake in Haliburton, Ontario — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Big Barnum Lake
Prices for Sep 18–20, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Follow Big Barnum Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Big Barnum Lake is a lake in Haliburton County, Ontario with an estimated average depth of about 34 feet.
Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2025-10-01. Grade methodology: LakeQuality methodology.
What Big Barnum Lake is good for
From access and monitoring records, not editorial picks.
- Clear water19.7 ft of visibility
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Big Barnum Lake is safe to swim in today is a call for the Ontario Ministry of the Environment, Conservation and Parks and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Big Barnum Lake
These are the measurements Ontario MECP publishes for Big Barnum Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 19.7 ft down. Phosphorus 5.3 µg/L. TSI 31.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | 6 m | Measured, not scored |
| Phosphorus | 5.3 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 31 | Oligotrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~10.4 m est. |
| Average Depth | ~3.7 m est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Ontario has not published bathymetry for Big Barnum Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Big Barnum Lake
Nearby Lakes in Haliburton
Frequently asked questions about Big Barnum Lake
Ask about Big Barnum Lake
Answers come straight from the public measurements and survey records on this page.
Where is Big Barnum Lake?
- Big Barnum Lake is a lake in Haliburton, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.
What is the water quality of Big Barnum Lake?
- Big Barnum Lake in Haliburton, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 6 m visibility. Phosphorus: 5.3 µg/L.
Is Big Barnum Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Big Barnum Lake?
- No published bathymetric survey covers Big Barnum Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 34 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Big Barnum Lake across LakeQuality
More lakes in Ontario
Other Lakes in Ontario
Oligotrophic Lakes in Ontario
Where this data comes from
Measurements for Big Barnum Lake come from Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring), not the EPA Water Quality Portal. Per-sample source details are not recorded for this lake. Contains information licensed under the Open Government Licence – Ontario. See data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)