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LakeQuality

Lake of Bays

Muskoka District, OntarioView mapDirections

Ontario MECP publishes the water-quality measurements for Lake of Bays. Here is what has been measured.

Clarity
5.5 m
Secchi · sampled 2025
Phosphorus
6 µg/L
Measured by Ontario MECP
Max depth
~38.1 m est.
GLOBathy model
  • 125 ft max depth

Lake of Bays in Muskoka District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 5.5 m visibility. Phosphorus: 6 µg/L.

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Lake of Bays is a lake in Muskoka District County, Ontario with an estimated average depth of about 125 feet.

Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2025-10-12. Grade methodology: LakeQuality methodology.

What Lake of Bays is good for

From access and monitoring records, not editorial picks.

  • Clear water18 ft of visibility

Swimming conditions

No reading

Not rated

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Lake of Bays 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.

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Water quality measurements for Lake of Bays

These are the measurements Ontario MECP publishes for Lake of Bays, 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 18 ft down. Phosphorus 6 µg/L. TSI 33.

MetricValueEPA condition class
Water Clarity (Secchi Depth)5.5 mMeasured, not scored
Phosphorus6 µg/LMeasured, not scored
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)33Oligotrophic

Low nutrients, clear water. No reading is a swimming clearance.

Lake Details

CharacteristicValue
Maximum Depth~38.1 m est.
Average Depth~34.1 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 Lake of Bays.

Lake Size & Watershed

Watershed (drainage) area
376 sq mi
Surface area
16,719 acres
Shoreline
113.2 mi
Elevation
1,030 ft

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 Lake of Bays

Nearby Lakes in Muskoka District

Frequently asked questions about Lake of Bays

Ask about Lake of Bays

Answers come straight from the public measurements and survey records on this page.

Where is Lake of Bays?

Lake of Bays is a lake in Muskoka District, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.

What is the water quality of Lake of Bays?

Lake of Bays in Muskoka District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 5.5 m visibility. Phosphorus: 6 µg/L.

Is Lake of Bays safe to swim in?

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

How deep is Lake of Bays?

No published bathymetric survey covers Lake of Bays, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 125 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

Where this data comes from

Measurements for Lake of Bays 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)