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LakeQuality

Lac des Trois Milles

Le Granit, QuébecView mapDirections

zone de transition méso-eutrophe

This is MELCCFP's own trophic classification for 2025, not a LakeQuality grade. See every year

Clarity
2.4 m
Secchi · sampled 2025
Phosphorus
11.5 µg/L
Measured by MELCCFP
Chlorophyll-a
4.1 µg/L
Measured by MELCCFP
Max depth
~12.5 m est.
GLOBathy model
  • 41 ft max depth

Lac des Trois Milles in Le Granit, Québec is classified zone de transition méso-eutrophe by Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec) for 2025. Water clarity: 2.4 m visibility. Phosphorus: 11.5 µg/L. Chlorophyll-a (algae): 4.1 µg/L.

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Lac des Trois Milles is a lake in Le Granit County, Québec with an estimated average depth of about 41 feet.

Source: Québec RSVL (MELCCFP) — not the EPA Water Quality Portal, last sampled 2025-08-01. Grade methodology: LakeQuality methodology.

Swimming conditions

No reading

Not rated

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

Whether Lac des Trois Milles is safe to swim in today is a call for le Ministère de l'Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Lac des Trois Milles

These are the measurements MELCCFP publishes for Lac des Trois Milles, 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 7.9 ft. Phosphorus 11.5 µg/L. Chlorophyll-a 4.1 µg/L.

MetricValueEPA condition class
Water Clarity (Secchi Depth)2.4 mMeasured, not scored
Phosphorus11.5 µg/LMeasured, not scored
Chlorophyll-a (Algae)4.1 µg/LMeasured, not scored

Lake Details

CharacteristicValue
Maximum Depth~12.5 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. Québec has not published bathymetry for Lac des Trois Milles.

Lake Size & Watershed

Watershed (drainage) area
6 sq mi
Surface area
250 acres
Shoreline
3.4 mi
Elevation
1,565 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 Lac des Trois Milles

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Frequently asked questions about Lac des Trois Milles

Ask about Lac des Trois Milles

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

Where is Lac des Trois Milles?

Lac des Trois Milles is a lake in Le Granit, Québec. MELCCFP classifies it zone de transition méso-eutrophe for 2025. This is MELCCFP's own trophic classification for 2025, not a LakeQuality grade.

What is the water quality of Lac des Trois Milles?

Lac des Trois Milles in Le Granit, Québec is classified zone de transition méso-eutrophe by Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec) for 2025. Water clarity: 2.4 m visibility. Phosphorus: 11.5 µg/L. Chlorophyll-a (algae): 4.1 µg/L.

Is Lac des Trois Milles safe to swim in?

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

How deep is Lac des Trois Milles?

No published bathymetric survey covers Lac des Trois Milles, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 41 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

The authority’s own classification

Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec) publishes its own classification for Lac des Trois Milles. It is shown here as theirs, in their words, and is not folded into the LakeQuality letter.

Most recent, 2025
zone de transition méso-eutrophe

This is MELCCFP's own trophic classification for 2025, not a LakeQuality grade.

A trophic class ranks how nutrient-rich a lake is, from oligotrophic at the low end to eutrophic at the high end. It describes nutrients and plant growth, not bacteria, and it is not a swimming clearance.

Earlier years (15 classified 2013–2025)
YearPublished class
2023zone de transition méso-eutrophe
2022zone de transition méso-eutrophe
2021zone de transition oligo-mésotrophe
2020zone de transition oligo-mésotrophe
2019classe mésotrophe
2018classe eutrophe
2017zone de transition méso-eutrophe
2016zone de transition méso-eutrophe
2015zone de transition méso-eutrophe
2014zone de transition méso-eutrophe
2013zone de transition méso-eutrophe

Published by Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec). A classification is not a same-day swimming clearance. See data sources.

Where this data comes from

Measurements for Lac des Trois Milles come from the Réseau de surveillance volontaire des lacs (RSVL), not the EPA Water Quality Portal. Per-sample source details are not recorded for this lake. MELCCFP RSVL (CC BY 4.0). See data sources.

Other records on this page

Lake size & watershed from HydroLAKES (HydroSHEDS)