Skip to main content
LakeQuality

Lac Thorne

Pontiac, QuébecView mapDirections

classe oligotrophe

This is MELCCFP's own trophic classification for 2022, not a LakeQuality grade. See every year

Clarity
6.8 m
Secchi · sampled 2022
Phosphorus
3.6 µg/L
Measured by MELCCFP
Chlorophyll-a
1.1 µg/L
Measured by MELCCFP

Lac Thorne in Pontiac, Québec is classified classe oligotrophe by Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec) for 2022. Water clarity: 6.8 m visibility. Phosphorus: 3.6 µg/L. Chlorophyll-a (algae): 1.1 µg/L.

Loading map…

Stays via Stay22

Stays near Lac Thorne

Compare lakeside cabins, hotels, and vacation rentals near Lac Thorne in Pontiac, Québec — 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 Lac Thorne

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 Lac Thorne’s readings

Email me when new measurements post for this lake. Updates stay free.


Or email

Lac Thorne is a lake in Pontiac County, Québec.

Source: Québec RSVL (MELCCFP) — not the EPA Water Quality Portal, last sampled 2022-08-01. Grade methodology: LakeQuality methodology.

What Lac Thorne is good for

From access and monitoring records, not editorial picks.

  • Clear water22.1 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 Lac Thorne 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.

Get alerts for Lac Thorne

Water quality measurements for Lac Thorne

These are the measurements MELCCFP publishes for Lac Thorne, 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 22.1 ft down. Phosphorus 3.6 µg/L. Chlorophyll-a 1.1 µg/L.

MetricValueEPA condition class
Water Clarity (Secchi Depth)6.75 mMeasured, not scored
Phosphorus3.6 µg/LMeasured, not scored
Chlorophyll-a (Algae)1.1 µg/LMeasured, not scored

Fishing Lac Thorne

Nearby Lakes in Pontiac

Frequently asked questions about Lac Thorne

Ask about Lac Thorne

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

Where is Lac Thorne?

Lac Thorne is a lake in Pontiac, Québec. MELCCFP classifies it classe oligotrophe for 2022. This is MELCCFP's own trophic classification for 2022, not a LakeQuality grade.

What is the water quality of Lac Thorne?

Lac Thorne in Pontiac, Québec is classified classe oligotrophe by Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (Québec) for 2022. Water clarity: 6.8 m visibility. Phosphorus: 3.6 µg/L. Chlorophyll-a (algae): 1.1 µg/L.

Is Lac Thorne safe to swim in?

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

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 Thorne. It is shown here as theirs, in their words, and is not folded into the LakeQuality letter.

Most recent, 2022
classe oligotrophe

This is MELCCFP's own trophic classification for 2022, 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 (2 classified 2021–2022)
YearPublished class
2021classe ultra-oligotrophe

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 Thorne 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.