Stony Lake

Where Stony Lake is

Stony Lake lies in the County of Peterborough, with shoreline in the Township of North Kawartha, the Township of Selwyn, the Township of Douro-Dummer and the Municipality of Trent Lakes.

How deep is Stony Lake?

The deepest mapped contour on Stony Lake is 31.0 meters, and the water within that boundary descends even farther. The chart is drawn from 537 depth contours recorded in Ontario’s transect survey.

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.

Stony Lake has 5 Lake Partner monitoring sites. Four 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 7133/7 at Mouse Is., with phosphorus sampled several times a year between spring and fall over 23 years to 2025. Its long-term mean phosphorus concentration is 13.32 micrograms per litre, within the mesotrophic band, which runs from 10 to 20.

One reading at site 7133/4, 63.0 micrograms per litre on 13 July 2021, is left out of the site’s mean. The province’s published file includes it.

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 153 clarity readings at site 7133/7 give a median Secchi depth of 4.2 meters.

Median Secchi depth by year at site 7133/7

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

Stony Lake Weather

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

Stony Lake weather

Water temperature

Ontario’s aquatic resource records class Stony Lake as a warm-water lake, with a mean depth of 5.87 meters against its maximum of 31.

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 Stony Lake. The weather page for Stony Lake carries the LastLake model’s surface water temperature for each day of the coming week. The province’s longest in-water record is kept on eight research lakes near Dorset, sampled since 1976. A reading is taken at the surface, at one meter, at each meter to seven and then every two meters to the bottom, about every two weeks through the open-water season and about monthly under ice. The record holds 5,240 readings at a depth of one meter.

At one meter the eight lakes track one another closely. On a day when several were sampled, the warmest and the coolest lake differed by about one degree in every month of the year, and a 12 meter deep lake and a 37 meter deep lake read within 0.2 degrees of each other from June to October. The weather of the year, and not the lake, sets most of the width of the band below.

Water temperature at a depth of one meter (eight lakes near Dorset, ON)

How depth changes the temperature

The chart below is the province’s record on Harp Lake, 37 meters deep, drawn as the median temperature at each depth for each month over 49 years. In July the water at one meter is 23 degrees, at five meters 15, at seven meters 9, and from 13 meters to the bottom under 6. By October the warm layer has deepened to seven meters and cooled to 11 degrees. In February the whole column sits between 1 and 4 degrees under the ice, coldest at the top.

A shallower lake in the same record warms sooner. Heney Lake, six meters deep, reads about 1.8 degrees warmer than Harp Lake at one meter from January to May, 0.8 degrees warmer from June to August, and the same or cooler from September.

See also Lake Water Temperature in Ontario

Stony Lake Water Level

Parks Canada measures the level of Stony Lake at a gauge on the lake, on the Trent-Severn Waterway, and posts one reading each weekday. The record below holds every reading since 1 January 2026, set against Parks Canada’s average, highest and lowest level for each day of the year.

Readings are provisional, posted by Parks Canada on weekdays, and are not intended for flood warning.

Fish in Stony Lake

Ontario’s aquatic resource records name 34 fish species in Stony Lake. The province’s other records for the lake name two further species, lake trout and brook trout. They appear in the records below.

Popular species in the province’s records

• Lake Whitefishtrout and whitefish
• Ciscotrout and whitefish
• Muskellungepike
• Walleyeperch
• Saugerperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Black Crappiesunfish
• Rock Basssunfish
• Pumpkinseedsunfish
• Bluegillsunfish
• Burbotcod
• Brown Bullheadcatfish
• Common Carpminnow

Spawning areas

Ontario maps 36 fish spawning records within the Stony Lake outline, for three different species, and all of them are mapped below.

By number of records

By area mapped

• Muskellunge25 areas50.2 ha
• Walleye10 areas12.6 ha
• White Sucker1 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 Stony Lake run from 1946 to 1989 and hold 124 releases. Muskellunge account for most of the fish: 8,107,279 released in 44 of the years between 1946 and 1989. The last recorded release was 100,000 muskellunge frys in 1989.

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

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for thirteen species taken from Stony Lake, tested for contaminants at a sampling location in Burleigh & Dummer Twps., Peterborough Twp. 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 17

Stony Lake lies in Fisheries Management Zone 17. Ontario sets its fishing seasons and catch limits by zone.

Fisheries management zones around Stony Lake

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

Stony Lake Ice Fishing

An ice hut on Stony Lake must be removed by March 1. 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). Stony Lake lies within FMZ 17.

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 17 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 In / Out Date

No ice record is kept on Stony Lake. The province’s nearest long record covers eight lakes near Dorset, about 99 kilometers away. It holds a date for every winter since 1975, observed by eye and from cameras set on the shore.

On those eight lakes the median date of complete ice cover is December 7 and the median date of complete ice loss is April 20, a median season of 134 days.

The date the ice forms has moved later through the record: a November 26 average across 1971 to 1980, and December 11 across 2011 to 2020. The date it leaves has moved by less than a day each decade over the same period. The two charts below are drawn to one scale of 26 days, so they can be read against each other.

Ice in date (eight lakes near Dorset, ON)

Ice out date (eight lakes near Dorset, ON)

Ice conditions

No public record reports the thickness or the condition of the ice on Stony 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

Getting on the water

Ten access marks are mapped on Stony Lake.

See also Boat Launches on Ontario Lakes

Islands and names

Stony Lake contains 417 islands in the Ontario Hydro Network’s outline, nine of them over 10 hectares and 206 under a tenth of a hectare. Forty-one of them lie mostly inside wetland the province’s Wetland With Significance dataset maps as marsh, open water or fen. The largest two, of 2.6 and 1.2 hectares, fall inside the Fairy Lake Island Complex and Hull South Bay wetlands.

Official names

Ontario’s geographic names register lists 130 official names on the water and its islands: 89 islands, thirteen bays, four shoals, twelve rocks and two narrows. A further 3 named points stand on the mainland shore.

Bays 13

• Burleigh Bay
• Butchers Bay
• Gilchrist Bay
• Grundys Bay
• Hamilton Bay
• Hull Bay
• Northey Bay
• Puffer Bay
• Quarry Bay
• South Bay
• Sunrise Bay
• Whetung Bay
• Young Bay

Shoals and rocks 16

• Confusion Shoal
• Cruiser Shoal
• Elephant Rock
• Falaasa Rock
• Five Foot Shoal
• Gull Rock
• Mouse Rock
• Old Tar
• Plum Pudding Rock
• Plum Stone
• Polly Cow Rock
• Sherin Shoal
• Sockeye Rock
• Sunken Rock
• The Black Rock
• Wash Rock

Harbours, cuts and narrows 2

• Boshing Narrows
• Foul Narrows

Points on the shore 3

• Snooky Point
• Stricker Point
• Young Point

Communities on the lake 6

• Crowes Landing
• Mount Julian
• McCrackens Landing
• Stonyridge
• Burleigh Falls
• Clarina

Nearby lakes

• White Lake4 km away
• Big Cedar Lake7 km away
• Clear Lake8 km away
• Lovesick Lake9 km away

All lakes

Questions about Stony Lake

• How deep is Stony Lake?

  Its deepest charted contour is 31 meters, and the water within it is deeper.

• How big is Stony Lake?

  Its surface covers 27.4 square kilometers and it holds 417 islands. Of its 229 kilometers of shoreline, 100 kilometers is the mainland shore and 129 kilometers is the shore of the islands.

• What fish are in Stony Lake?

  Ontario’s aquatic resource records name 34 species, among them walleye, smallmouth bass, largemouth bass, muskellunge, lake whitefish and yellow perch. The lake’s spawning, consumption and stocking records also name lake trout and brook trout.

• Is the water clear?

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

• Is there a public boat launch?

  Records mark one boat launch.