Map of Onaping Lake with depth contours

Onaping Lake

47.1389° N, 81.5208° W

Depth contours from the 1974 government survey. Not for navigation.

Download the depth map (SVG)

Onaping Lake is 48.8 m deep at its deepest point, deeper than 93% of the 2,688 surveyed lakes in Ontario. It covers 68.6 km² and lies 5.6 km south of Ruel.

Government surveys have recorded 10 fish species here, including lake whitefish, walleye and burbot.

Maximum depth
48.8 msurveyed 1974
deeper than 93% of the 2,688 surveyed lakes in Ontario
Area
68.6 km²
larger than 99% of the 18,731 lakes in Ontario
Shoreline
524 km
longer than 99% of the 18,731 lakes in Ontario
Water clarity
3.4 mSecchi depth, 2025
less clear than 53% of the 1,251 monitored lakes in Ontario
Fish species
10
more than 73% of the 2,454 surveyed lakes in Ontario
Elevation
402 m

Today on the water

3.6 °C

Partly CloudyWind SW 10 km/h

Observed at Sudbury (Greater), as of 3:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.3 m. Around 8 a.m., wind from the northwest: the northwest shore is sheltered, waves build toward the southeast 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 10NW 20NW 20NW 20NW 10var. 5SE 10
Gusts km/h4040
Waves (est.) m0.10.10.30.3
Temp. °C54710121075
Precip. %3030302020000

Tonight: Mainly cloudy with 30 percent chance of showers. Wind west 20 km/h gusting to 40 becoming light this evening. Low plus 4.

Weather: Sudbury (Greater) (local forecast), as of 3:02 a.m. EDT

Sun and moon

Civil dawn
7:05 a.m.
Sunrise
7:36 a.m.
Sunset
6:49 p.m.
Civil dusk
7:20 p.m.
Moonrise
6:27 a.m.
Moonset
6:08 p.m.
Moon
Waning crescent, 1% lit

Air Quality Health Index

1 low risk

Sudbury, as of 2:00 a.m. EDT

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

9% of Onaping Lake 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 1974 records a maximum depth of 48.8 m, drawn from 320 depth contours.

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 Depths are from government surveys and may be outdated.

Fish

Sport fish by the share of the 6 government surveys (2010–2010) that recorded them.

  • Lake Whitefish4 of 6
  • WalleyeStocked3 of 6
  • Burbot1 of 6
  • Cisco1 of 6
  • Northern Pike1 of 6
  • Smallmouth Bass1 of 6
  • Yellow Perch1 of 6
  • Lake TroutStocked
Forage fish and other species (2)

Forage fish

  • Trout-Perch 1

Other

  • White Sucker 2

Numbers are the surveys that recorded each species.

Stocking

Lake Trout27,278 fish in 7 years, most recently 2024

Walleye10,000 fish in 1 year, most recently 2018

All stocking records (9)
YearSpeciesFishStage
2024Lake Trout3,504Yearlings
2024Lake Trout593Adult
2023Lake Trout560Yearlings
2022Lake Trout4,349Yearlings
2020Lake Trout5,495Yearlings
2019Lake Trout5,077Yearlings
2018Lake Trout4,500Yearlings
2018Walleye10,000Fry
2017Lake Trout3,200Yearlings

Eating your catch

The provincial guide to eating fish (2026) sets limits for 4 species from Onaping Lake. Maximum meals per month:

SpeciesLengthGeneral populationSensitive population*Contaminant
Northern Pike55-60 cm4Do not eatMercury
Smallmouth Bass35-40 cm8Do not eatMercury
Walleye40-45 cm4Do not eatMercury
Burbot (Ling)50-55 cm4Do not eatMercury

* As defined in the guide, including children and people who are or may become pregnant. Limits are for the length the guide lists most often; they change with the size of the fish. Read the official guide

Fishing regulations: Fisheries Management Zone 10. Check seasons and limits before you fish.

Water

Clarity was measured with a Secchi disk in 5 years between 2021 and 2025; the latest annual mean is 3.4 m.

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