Map of Les Trois Lacs with depth contours

Les Trois Lacs

45.8006° N, 71.8889° W

Depth contours from the 1975 government survey. Not for navigation.

Download the depth map (SVG)

Les Trois Lacs is 10.1 m deep at its deepest point, shallower than 74% of the 1,506 surveyed lakes in Quebec. It covers 2.42 km² and lies beside Le Secteur-des-Lacs.

Maximum depth
10.1 msurveyed 1975
shallower than 74% of the 1,506 surveyed lakes in Quebec
Area
2.42 km²
larger than 85% of the 29,407 lakes in Quebec
Shoreline
16.1 km
longer than 85% of the 29,407 lakes in Quebec
Water clarity
1.4 mSecchi depth, 2024
less clear than 95% of the 805 monitored lakes in Quebec
Elevation
160 m

Today on the water

4.3 °C

ClearWind SW 5 km/h

Observed at Val-des-Sources, as of 3:08 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 m. Around 9 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.

Hourly forecast, next 24 hours
Time4 a.m.7 a.m.10 a.m.1 p.m.4 p.m.7 p.m.10 p.m.1 a.m.
Wind km/hW 10W 10W 20W 20W 20W 20W 15W 10
Gusts km/h404040
Waves (est.) m0.10.10.20.20.2
Temp. °C9891110753
Precip. %60404040404000

Tonight: Mainly cloudy with 60 percent chance of showers. Risk of a thunderstorm this evening. Wind west 20 km/h gusting to 40 becoming light this evening. Low 8.

Weather: Val-des-Sources (local forecast), as of 3:09 a.m. EDT

Sun and moon

Civil dawn
6:26 a.m.
Sunrise
6:56 a.m.
Sunset
6:12 p.m.
Civil dusk
6:42 p.m.
Moonrise
5:46 a.m.
Moonset
5:30 p.m.
Moon
Waning crescent, 1% lit

Data Source: Environment and Climate Change Canada. Local times.

How waves are estimated

Significant wave height from the forecast hourly wind and the open-water distance (fetch) upwind, using the SMB method (US Army Corps of Engineers Shore Protection Manual, 1984), rounded up to the next 0.1 m. It is not a measurement: gusts, leftover swell and shoals can make water rougher. Under 0.2 m: calm; 0.2–0.5 m: choppy; over 0.5 m: rough.

Depth

54% of Les Trois Lacs is shallower than 3 m, and 20% is deeper than 5 m.

How to read it: the lake’s area is sorted from the shore to the deepest point. Where the curve is flat, large areas share one depth (flats and weed beds); where it drops, depth changes quickly (drop-offs).

The government depth survey from 1975 records a maximum depth of 10.1 m, drawn from 64 depth contours.

Not for navigation. Depths are from government surveys and may be outdated.

Water

Trophic status from the latest monitoring: eutrophic.

Clarity was measured with a Secchi disk in 10 years between 2011 and 2024; the latest annual mean is 1.4 m.

Water clarity (Secchi depth, m)
Total phosphorus (µg/L)