Kennebec Lake

Where Kennebec Lake is

Kennebec Lake lies in the County of Frontenac, within the Township of Central Frontenac.

How deep is Kennebec Lake?

The deepest mapped contour on Kennebec Lake is 30.5 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 22 depth contours for Kennebec 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.

Kennebec Lake has 2 Lake Partner monitoring sites. Two have reported phosphorus for the three or more years the province requires before a status is assigned. All are classified mesotrophic.

The longest record is held by site 6977/3 at W end-Salmon R Mouth, with phosphorus sampled once a year over 24 years to 2025. Its long-term mean phosphorus concentration is 10.17 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 116 clarity readings at site 6977/3 give a median Secchi depth of 2.6 meters.

Median Secchi depth by year at site 6977/3

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

Kennebec Lake Weather

The weather page for Kennebec Lake carries the forecast over the water, wave heights across the lake, and the modelled water temperature.

Kennebec Lake weather

Water temperature

Ontario’s aquatic resource records class Kennebec Lake as a cold-water lake, with a mean depth of 7.9 meters against its maximum of 30.5.

A lake separates into layers through the summer where it is deep enough. Sunlight and wind warm and mix the upper few meters, and beneath a band of rapid cooling, the thermocline, the water stays cold. A shallow lake mixes to the bottom instead and warms through, sooner in spring and later into autumn.

No provincial monitoring station records water temperature on Kennebec Lake. The LastLake model computes the temperature of its surface water for each day from the daily mean air temperature at Environment Canada’s Centreville climate station, 37 kilometers from the lake, or the next nearest station when its record is incomplete, and from the lake’s area of 511 hectares and its mean depth of 7.9 meters.

Each day’s figure carries the model’s typical error for that month on lakes of the same size. The figure in the chart below is the temperature near the surface, away from the shoreline. Bays, shallows and water deeper below the surface differ in temperature. Temperature is not measured when ice covers the lake. The weather page for Kennebec Lake carries the model’s figures for the past weeks and the coming week.

See also Lake Water Temperature in Ontario

Fish in Kennebec Lake

Ontario’s aquatic resource records name 15 fish species in Kennebec Lake. The province’s other records for the lake name two further species, smallmouth bass and lake trout. They appear in the records below.

Popular species in the province’s records

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

Spawning areas

Ontario maps 21 fish spawning records within the Kennebec Lake outline, for five different species, and all of them are mapped below.

By number of records

By area mapped

• Largemouth Bass5 areas0.8 ha
• Blue Gill5 areas0.8 ha
• Smallmouth Bass5 areas0.8 ha
• Pumpkinseed5 areas0.8 ha
• Northern Pike1 area0.1 ha

The federal Fisheries Act prohibits the harmful alteration, disruption or destruction of fish habitat without an authorization, so a dock, dredging, infill or shoreline work at a mapped spawning area is reviewed on that basis.

Stocking history

Ontario’s stocking records for Kennebec Lake run from 1946 to 1985 and hold 30 releases. Walleye account for most of the fish: 2,602,217 released in eleven of the years between 1946 and 1985. The last recorded release was 2,217 walleye fingerlings in 1985.

The province’s record of stocking for recreational fishing, kept from 2016, lists no release into Kennebec Lake.

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for six species taken from Kennebec Lake, tested for contaminants at a sampling location in Kennebec Twp., Frontenac 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. 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 18

Kennebec Lake lies in Fisheries Management Zone 18. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Kennebec Lake

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

Kennebec Lake Ice Fishing

An ice hut on Kennebec 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). Kennebec Lake lies within FMZ 18.

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 18 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 conditions

No public record reports the thickness or the condition of the ice on Kennebec 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 and When the Lakes Will Freeze This Winter

Islands and names

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

Official names

Ontario’s geographic names register lists 1 official name on the water and its islands: .

Nearby lakes

• Big Gull Lake12 km away
• Kashwakamak Lake15 km away
• Eagle Lake23 km away
• Sharbot Lake23 km away

All lakes

Questions about Kennebec Lake

• How deep is Kennebec Lake?

  Its deepest charted contour is 30.5 meters, and the water within it is deeper.

• How big is Kennebec Lake?

  Its surface covers 5.1 square kilometers and it holds 14 islands. Of its 36 kilometers of shoreline, 33 kilometers is the mainland shore and 3 kilometers is the shore of the islands.

• What fish are in Kennebec Lake?

  Ontario’s aquatic resource records name fifteen species, among them walleye, largemouth bass, northern pike and yellow perch. The lake’s spawning, consumption and stocking records also name smallmouth bass and lake trout.

• Is the water clear?

  All two monitoring sites with a phosphorus status are classified mesotrophic, the middle of the province’s three bands.