Head Lake

Where Head Lake is

Head Lake lies in the County of Haliburton, within the Municipality of Dysart Et Al.

How deep is Head Lake?

The deepest mapped contour on Head Lake is 4.6 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 4 depth contours for Head 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.

Head Lake has 1 Lake Partner monitoring site, which has yet reported phosphorus for the three years the province requires before a status is assigned.

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.

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

Head Lake Weather

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

Head Lake weather

Water temperature

Ontario’s aquatic resource records class Head Lake as a cool-water lake.

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 Head Lake. The weather page for Head 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

Fish in Head Lake

Ontario’s aquatic resource records name 9 fish species in Head Lake.

Popular species in the province’s records

• Ciscotrout and whitefish
• Muskellungepike
• Walleyeperch
• Yellow Perchperch
• Smallmouth Basssunfish
• Largemouth Basssunfish
• Black Crappiesunfish
• Pumpkinseedsunfish

Spawning areas

Ontario maps 9 fish spawning records within the Head Lake outline, for three different species, and all of them are mapped below.

By number of records

By area mapped

• Largemouth Bass4 areas0.6 ha
• Muskellunge3 areas0.3 ha
• Walleye2 areas0.7 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 Head Lake run from 1946 to 2015 and hold 27 releases. Walleye account for most of the fish: 1,089,275 released in eleven of the years between 1962 and 2015. The last recorded release was 220,000 walleye frys in 2015.

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

Eating the fish

The 2026 Guide to Eating Ontario Fish carries consumption advice for one species taken from Head Lake, tested for contaminants at a sampling location in Dysart Twp., Haliburton 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 15

Head Lake lies in Fisheries Management Zone 15. Ontario sets its fishing seasons and catch limits by zone. The province describes it as a zone of many natural lake trout and brook trout lakes, with a well-developed road network and moderate angling effort.

Fisheries management zones around Head Lake

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

Head Lake Ice Fishing

An ice hut on Head Lake must be removed by March 31. 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). Head Lake lies within FMZ 15.

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 15 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 Head Lake in 99 springs between 1900 and 2001. The median date is April 20. The earliest recorded break-up is March 28 in 1945, and the latest is May 5 in 1904.

Across the 99 recorded springs the median date has moved by less than a day 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 holds the ice-out dates for Head Lake, and an ice-in date for only six of those winters, too few to draw on.

Ice out dates for 99 recorded springs between 1900 and 2001

Ice conditions

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

Nearby lakes

• Soyers Lake8 km away
• Kashagawigamog Lake8 km away
• Drag Lake9 km away
• Eagle Lake10 km away

All lakes

Questions about Head Lake

• How deep is Head Lake?

  Its deepest charted contour is 4.6 meters, and the water within it is deeper.

• How big is Head Lake?

  Its surface covers 0.7 square kilometers, with 5 kilometers of shoreline.

• What fish are in Head Lake?

  Ontario’s aquatic resource records name nine species, among them walleye, smallmouth bass, largemouth bass, muskellunge, yellow perch and black crappie.