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Map of Lac Saint-Joseph with depth contours

Lac Saint-Joseph

46.9139° N, 71.6442° W

Depth contours from the 1973 government survey. Not for navigation.

Download the depth map (SVG)

Lac Saint-Joseph, Quebec. 46.9139° N, 71.6442° W

Maximum depth 37.6 m (1973 survey). Scale bar on the map.

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 Depths are from government surveys and may be outdated.

borealbound.ca/lakes/qc/lac-saint-joseph/, compiled October 9, 2026

  • Canadian Geographical Names Database, Natural Resources Canada. Contains information licensed under the Open Government Licence – Canada.
  • HydroLAKES v1.0, Messager et al. 2016 / WWF HydroSHEDS. Licensed under CC BY 4.0.
  • Census boundaries and population, 2021, Statistics Canada. Adapted from Statistics Canada. This does not constitute an endorsement by Statistics Canada.
  • Géobase des bathymétries de lac du Québec (GBLQ), Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs. Licensed under CC BY 4.0. Source: Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP), Données Québec.
  • États trophiques des lacs (RSVL), Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs. Licensed under CC BY 4.0. Source: Ministère de l’Environnement, de la Lutte contre les changements climatiques, de la Faune et des Parcs (MELCCFP), Données Québec.
  • City page weather forecasts and alerts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
  • Air Quality Health Index observations and forecasts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
  • Photographs, Wikimedia Commons contributors. Each photo carries its own licence (CC0, public domain, CC BY or CC BY-SA), credited where shown.

Lac Saint-Joseph is 37.6 m deep at its deepest point, deeper than 88% of the 1,506 surveyed lakes in Quebec. It covers 11.3 km² and lies beside Fossambault-sur-le-Lac.

Maximum depth
37.6 msurveyed 1973
deeper than 88% of the 1,506 surveyed lakes in Quebec
Area
11.3 km²
larger than 96% of the 29,407 lakes in Quebec
Shoreline
25.4 km
longer than 90% of the 29,407 lakes in Quebec
Water clarity
3.4 mSecchi depth, 2025
less clear than 58% of the 805 monitored lakes in Quebec
Elevation
157 m

Today on the water

YELLOW ADVISORY - FROST · issued 8:47 a.m. EDT
Temperatures will drop to near freezing overnight tonoght as well as overnight Saturday to Sunday.

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 12:47 a.m. EDT Saturday

8.2 °C

Wind W 8 km/h

Observed at Donnacona, as of 10:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.3 m. Around 11 a.m., wind from the west: the west shore is sheltered, waves build toward the east shore.

Time11 a.m.2 p.m.5 p.m.8 p.m.11 p.m.2 a.m.5 a.m.8 a.m.
Wind km/hW 20W 20W 20W 20W 20W 20W 20W 15
Gusts km/h404040
Waves (est.) m0.30.30.30.3
Temp. °C9111063033
Precip. %30303000000

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 10:01 a.m. EDT

Sun and moon

Civil dawn
6:25 a.m.
Sunrise
6:56 a.m.
Sunset
6:10 p.m.
Civil dusk
6:40 p.m.
Moonrise
5:46 a.m.
Moonset
5:28 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 Saint-Joseph is shallower than 3 m, and 39% 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 1973 records a maximum depth of 37.6 m, drawn from 36 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 22 years between 2004 and 2025; the latest annual mean is 3.4 m.

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

Photos

Lac Saint-Joseph - Vue aérienne 2024
Photo: Gabriel Picard, CC BY-SA 4.0, via Wikimedia Commons
Vue aérienne - Lac Saint-Joseph 2023 (1)
Photo: Gabriel Picard, CC BY-SA 4.0, via Wikimedia Commons
Vue aérienne - Lac Saint-Joseph 2023 (2)
Photo: Gabriel Picard, CC BY-SA 4.0, via Wikimedia Commons