Map of Lac Saint-Pierre with depth contours

Lac Saint-Pierre

48.4603° N, 67.6402° W

Depth contours from the 1976 government survey. Not for navigation.

Download the depth map (SVG)

Lac Saint-Pierre is 14.6 m deep at its deepest point, shallower than 57% of the 1,506 surveyed lakes in Quebec. It covers 0.18 km² and lies 3.9 km south of Saint-Agricole.

Maximum depth
14.6 msurveyed 1976
shallower than 57% of the 1,506 surveyed lakes in Quebec
Area
0.18 km²
smaller than 70% of the 29,407 lakes in Quebec
Shoreline
1.9 km
shorter than 86% of the 29,407 lakes in Quebec
Water clarity
6.3 mSecchi depth, 2025
clearer than 87% of the 805 monitored lakes in Quebec
Elevation
259 m

Today on the water

3.6 °C

Wind N 2 km/h

Observed at Amqui, as of 4:00 a.m. EDT

calm Estimated waves, next 12 hours: up to 0.1 m. Around 5 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.

Hourly forecast, next 24 hours
Time5 a.m.8 a.m.11 a.m.2 p.m.5 p.m.8 p.m.11 p.m.2 a.m.
Wind km/hW 20W 20W 20W 20W 20W 20W 20W 20
Gusts km/h4040404040404040
Waves (est.) m0.10.10.10.10.1
Temp. °C35887543
Precip. %0003030000

Tonight: Partly cloudy. Fog patches. Wind west 20 km/h gusting to 40. Low plus 3.

Weather: Amqui (local forecast), as of 4:02 a.m. EDT

Sun and moon

Civil dawn
6:10 a.m.
Sunrise
6:41 a.m.
Sunset
5:53 p.m.
Civil dusk
6:24 p.m.
Moonrise
5:30 a.m.
Moonset
5:10 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

40% of Lac Saint-Pierre is shallower than 3 m, and 47% 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 1976 records a maximum depth of 14.6 m, drawn from 8 depth contours.

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 Depths are from government surveys and may be outdated.

Water

Trophic status from the latest monitoring: oligotrophic.

Clarity was measured with a Secchi disk in 9 years between 2010 and 2025; the latest annual mean is 6.3 m.

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