Third Lake
Parry Sound District, OntarioView mapDirections
Ontario MECP publishes the water-quality measurements for Third Lake. Here is what has been measured.
- 25 ft max depth
Third Lake in Parry Sound District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 2.9 m visibility. Phosphorus: 9.5 µg/L.
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Third Lake is a lake in Parry Sound District County, Ontario with an estimated average depth of about 25 feet.
Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2025-08-20. Grade methodology: LakeQuality methodology.
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Third 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 Third Lake
These are the measurements Ontario MECP publishes for Third Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.5 ft. Phosphorus 9.5 µg/L. TSI 41.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.9 m | Measured, not scored |
| Phosphorus | 9.5 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~7.6 m est. |
| Average Depth | ~5.2 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 Third 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.
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Frequently asked questions about Third Lake
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Answers come straight from the public measurements and survey records on this page.
Where is Third Lake?
- Third Lake is a lake in Parry Sound District, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.
What is the water quality of Third Lake?
- Third Lake in Parry Sound District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 2.9 m visibility. Phosphorus: 9.5 µg/L.
Is Third Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Third Lake?
- No published bathymetric survey covers Third Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 25 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
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Where this data comes from
Measurements for Third 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)