Mercer Lake
Nipissing District, OntarioView mapDirections
Ontario MECP publishes the water-quality measurements for Mercer Lake. Here is what has been measured.
- 35 ft max depth
Mercer Lake in Nipissing District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 1.4 m visibility. Phosphorus: 21.5 µg/L.
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Mercer Lake is a lake in Nipissing District County, Ontario with an estimated average depth of about 35 feet.
Source: Ontario open-data programmes (Lake Partner Program and Broad-scale Monitoring) — not the EPA Water Quality Portal, last sampled 2025-08-01. 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 Mercer 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 Mercer Lake
These are the measurements Ontario MECP publishes for Mercer Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 4.6 ft. Phosphorus 21.5 µg/L. TSI 52.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.4 m | Measured, not scored |
| Phosphorus | 21.5 µg/L | Measured, not scored |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~10.7 m est. |
| Average Depth | ~4.3 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 Mercer 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 Mercer Lake
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Answers come straight from the public measurements and survey records on this page.
Where is Mercer Lake?
- Mercer Lake is a lake in Nipissing District, Ontario. Its water-quality measurements are published by Ontario MECP and shown on this page as reported.
What is the water quality of Mercer Lake?
- Mercer Lake in Nipissing District, Ontario has water-quality measurements published by Ontario MECP, shown here as reported. Water clarity: 1.4 m visibility. Phosphorus: 21.5 µg/L.
Is Mercer Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Mercer Lake?
- No published bathymetric survey covers Mercer Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 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 Mercer 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)