Map of Lac Montauban with depth contours

Lac Montauban

46.8946° N, 72.1768° W

Depth contours from the 2012 government survey. Not for navigation.

Download the depth map (SVG)

Lac Montauban is 43.2 m deep at its deepest point, deeper than 91% of the 1,506 surveyed lakes in Quebec. It covers 7.88 km² and lies 6.8 km northeast of Lac-Blanc.

Maximum depth
43.2 msurveyed 2012
deeper than 91% of the 1,506 surveyed lakes in Quebec
Area
7.88 km²
larger than 94% of the 29,407 lakes in Quebec
Shoreline
62.7 km
longer than 96% of the 29,407 lakes in Quebec
Water clarity
4 mSecchi depth, 2025
clearer than 55% of the 805 monitored lakes in Quebec
Elevation
173 m

Today on the water

YELLOW ADVISORY - FROST · issued 4:39 a.m. EDT
Temperatures will drop to near the freezing mark overnight tonight.

Take preventative measures to protect cold-sensitive plants, trees, and crops.

Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to QCstorm@ec.gc.ca or post reports on social media using #QCStorm.

Official alert on weather.gc.ca · expires 11:29 p.m. EDT

3.8 °C

Wind calm

Observed at Donnacona, as of 7:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 m. Around 8 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.

Hourly forecast, next 24 hours
Time8 a.m.11 a.m.2 p.m.5 p.m.8 p.m.11 p.m.2 a.m.5 a.m.
Wind km/hW 15W 20W 20W 20W 20W 20W 20W 20
Gusts km/h404040
Waves (est.) m0.20.20.20.20.2
Temp. °C8911106303
Precip. %303030300000

Today: A mix of sun and cloud with 30 percent chance of showers. Wind becoming west 20 km/h gusting to 40 this morning. High 11. UV index 3 or moderate.

Weather: Donnacona (local forecast), as of 7:01 a.m. EDT

Sun and moon

Civil dawn
6:27 a.m.
Sunrise
6:58 a.m.
Sunset
6:12 p.m.
Civil dusk
6:43 p.m.
Moonrise
5:48 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

14% of Lac Montauban is deeper than 20 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 2012 records a maximum depth of 43.2 m, drawn from 107 depth contours.

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 Depths are from government surveys and may be outdated.

Water

Trophic status from the latest monitoring: oligo-mesotrophic (transition).

Clarity was measured with a Secchi disk in 19 years between 2007 and 2025; the latest annual mean is 4 m.

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