Chesley Lake

Where Chesley Lake is

Chesley Lake lies in the County of Bruce, within the Town of South Bruce Peninsula.

How deep is Chesley Lake?

The deepest mapped contour on Chesley Lake is 16.8 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 15 depth contours for Chesley Lake.

See also Ontario's Largest and Deepest Lakes

Surveyed Depths

Ontario has surveyed the depths of several thousand of its lakes over more than half a century. Later surveys were conducted by boat with satellite positioning and produced hundreds of thousands of soundings per lake. Earlier surveys were charted by running transects across the water and drawing depth contours by hand.

Water quality

Ontario’s Lake Partner Program is a volunteer monitoring network. Participants collect water samples for phosphorus analysis and measure water clarity through the summer with a Secchi disk. Most sites are sampled for phosphorus once a year, in spring, and some several times a year between spring and fall. Phosphorus in many lakes rises through the summer, so the two kinds of average are measured on different bases.

Phosphorus is the nutrient that controls how much algae a lake can grow. A lake with little phosphorus stays clear and supports cold-water fish such as lake trout. As phosphorus rises, algae increase, the water clouds, and oxygen in the deep water falls as the algae decay. The province classifies each monitoring site by its average phosphorus:

• Oligotrophic, below 10 micrograms per litre: clear water and low algae.
• Mesotrophic, from 10 to 20: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom.
• Eutrophic, above 20: nutrient-rich water, prone to algal blooms and low oxygen at depth.

Chesley Lake has 1 Lake Partner monitoring site. It has reported phosphorus for the three or more years the province requires before a status is assigned, and is classified mesotrophic.

The longest record is held by site 6865/1 at Mid Lake, deep spot, with phosphorus sampled several times a year between spring and fall over 8 years to 2025. Its long-term mean phosphorus concentration is 14.69 micrograms per litre, within the mesotrophic band, which runs from 10 to 20.

A Secchi disk is a white or black-and-white plate lowered on a marked line until it disappears from view. The depth at which it vanishes is the Secchi depth, a direct measure of water clarity. Clearer water gives a deeper reading.

The 58 clarity readings at site 6865/1 give a median Secchi depth of 3.0 meters.

Median Secchi depth by year at site 6865/1

See also Lake Water Quality and Blue-Green Algae in Ontario

Fish in Chesley Lake

Ontario’s aquatic resource records name 19 fish species in Chesley Lake.

Popular species in the province’s records

• Northern Pikepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Rock Basssunfish
• Pumpkinseedsunfish
• Bluegillsunfish
• Brown Bullheadcatfish

Stocking history

Ontario’s stocking records for Chesley Lake run from 1946 to 2015 and hold 33 releases. Walleye account for most of the fish: 5,065,528 released in 22 of the years between 1946 and 2015. The last recorded release was 4,000 walleye fingerlings in 2015.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for five species taken from Chesley Lake, tested for contaminants at a sampling location in Amabel Twp., Bruce Co. Each figure below is the most meals a month the guide advises for a fish of that length. Where mercury sets the advice, the figure falls as the fish gets longer, because mercury accumulates over a fish’s life. Where the guide has no result yet for certain contaminants at a location, it sets a precautionary limit of 16 meals a month. A zero means the guide advises no meals of that fish at that size.

General population: adultsSensitive population: children under fifteen, women who are or may become pregnant

Fisheries Management Zone 16

Chesley Lake lies in Fisheries Management Zone 16. Ontario sets its fishing seasons and catch limits by zone. The province describes it as a zone of large river systems, with Lake Simcoe and Lake Couchiching its large lakes, carrying important recreational and tourism fisheries under high fishing effort.

Fisheries management zones around Chesley Lake

See also Fishing Seasons in Ontario, Zone by Zone and Fish Stocking in Ontario Lakes

Chesley Lake Ice Fishing

An ice hut on Chesley Lake must be removed by March 15. The province sets dates for ice hut removal as a safety measure to ensure huts are removed before thawing occurs. One date applies to an entire fisheries management zone (FMZ). Chesley Lake lies within FMZ 16.

An ice hut must also be removed before the ice breaks up, whether or not that date has passed. The deadline clears huts from the ice ahead of the thaw and does not close the fishing season.

Registration is required in FMZ 16 for an ice hut built of anything other than fabric, and for a fabric tent covering seven square meters or more. Registration is free, and the number is displayed on the outside of the hut.

Ice Out Date

The ice has been recorded leaving Chesley Lake in eleven springs between 1985 and 1995. The median date is April 8. The earliest recorded break-up is April 1 in 1986, and the latest is April 20 in 1992.

Across the eleven recorded springs the date has moved later by about 4.2 days each decade.

The record was contributed by Peter J. Dillon, Ontario Ministry of the Environment to the Global Lake and River Ice Phenology Database. The record only holds the ice-out dates for Chesley Lake, and no ice-in date.

Ice conditions

No public record reports the thickness or the condition of the ice on Chesley Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.

See also Lake Ice in Ontario

Islands and names

Chesley Lake contains four islands in the Ontario Hydro Network’s outline, zero of them over 10 hectares and two under a tenth of a hectare.

Nearby lakes

• Miller Lake62 km away
• Lake Eugenia63 km away
• Conestogo Lake103 km away
• Farlain Lake103 km away

All lakes

Questions about Chesley Lake

• How deep is Chesley Lake?

  Its deepest charted contour is 16.8 meters, and the water within it is deeper.

• How big is Chesley Lake?

  Its surface covers 2.1 square kilometers and it holds 4 islands. Of its 10 kilometers of shoreline, 9 kilometers is the mainland shore and 1 kilometer is the shore of the islands.

• What fish are in Chesley Lake?

  Ontario’s aquatic resource records name nineteen species, among them walleye, smallmouth bass, largemouth bass, northern pike and yellow perch.

• Is the water clear?

  The one monitoring site with a phosphorus status is classified mesotrophic, the middle of the province’s three bands.