Lanark County, Ontario
Dalhousie Lake
A maximum recorded depth of 18.8 meters, from 21,277 soundings taken in the province's 2008 survey, on the Mississippi River in the Township of Lanark Highlands. The aquatic resource record lists 28 species.
- Surface
- 6.2 km²
- Shoreline
- 16 km
- Islands
- 0
- Max depth
- 18.8 m
- Soundings
- 21,277
All figures are derived from Ontario’s survey records.
Where Dalhousie Lake is
Dalhousie Lake lies in the County of Lanark, within the Township of Lanark Highlands.
How deep is Dalhousie Lake?
Dalhousie Lake reaches a maximum recorded depth of 18.8 meters, determined from 21,277 soundings.
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 a water sample each spring for phosphorus analysis and measure water clarity through the summer with a Secchi disk.
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 spring phosphorus. Below 10 micrograms per litre is oligotrophic: clear water and low algae. From 10 to 20 is mesotrophic: moderately productive water, with more algae and weed growth than an oligotrophic lake but rarely a bloom. Above 20 is eutrophic: nutrient-rich water, prone to algal blooms and low oxygen at depth.
A Secchi disk is a 20 centimeter 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.
Dalhousie Lake has 1 Lake Partner monitoring site, which has yet reported phosphorus for the three years the province requires before a status is assigned.
Fish in Dalhousie Lake
Ontario’s aquatic resource records name 28 fish species in Dalhousie Lake. The record took effect on 1 November 2018, and it compiles what field biologists had reported by then.
Fourteen of the 28 species in the province’s records
Brook Trouttrout and whitefish
Lake Whitefishtrout and whitefish
Ciscotrout and whitefish
Northern Pikepike
Walleyeperch
Yellow Perchperch
Smallmouth Basssunfish
Largemouth Basssunfish
Black Crappiesunfish
Rock Basssunfish
Pumpkinseedsunfish
Bluegillsunfish
Burbotcod
Brown Bullheadcatfish
| Family | Species |
|---|---|
| Perch | logperch |
| Catfish | yellow bullhead |
| Sucker | shorthead redhorse, white sucker |
| Minnow | bluntnose minnow, common shiner, creek chub, golden shiner |
| Herring | alewife |
| Eel | american eel |
| Silverside | brook silverside |
| Trout-perch | trout-perch |
| Other | fallfish, pumpkinseed x bluegill |
Spawning areas
Ontario maps 3 fish spawning records within the Dalhousie Lake outline, for two species, all of them mapped areas. Every record is recorded as verified and presently suitable, and none is classed as sensitive.
By number of records
By area mapped
- Smallmouth Bass2 areas2.2 ha
- Northern Pike1 area0.7 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 Dalhousie Lake run from 1946 to 1991 and hold 51 releases. Walleye account for most of the fish: 11,032,052 released in 21 of the years between 1946 and 1991. The last recorded release was 8,377 walleye fingerlings in 1991.
| Species | Years | Years with a release | Fish released |
|---|---|---|---|
| Walleye | 1946 to 1991 | 21 | 11,032,052 |
| Smallmouth Bass | 1946 to 1971 | 22 | 40,550 |
| Largemouth Bass | 1958 to 1964 | 4 | 3,500 |
The province’s current stocking programme, recorded from 2016, lists no release into Dalhousie Lake.
Eating the fish
The 2025 Guide to Eating Ontario Fish carries consumption advice for six species taken from Dalhousie Lake, tested for contaminants at a sampling location in Dalhousie Twp., Lanark Co. Each figure below is the most meals a month the guide advises for a fish of that length. The advice 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
| Length, cm | 35 to 40 | 40 to 45 | 45 to 50 |
|---|---|---|---|
| General population | 32 | 16 | 16 |
| Sensitive population | 12 | 8 | 8 |
| Length, cm | 20 to 25 | 25 to 30 | 30 to 35 | 35 to 40 | 40 to 45 | 45 to 50 | 50 to 55 | 55 to 60 | 60 to 65 | 65 to 70 | 70 to 75 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| General population | 16 | 16 | 16 | 12 | 8 | 4 | 4 | 4 | 2 | 2 | 2 |
| Sensitive population | 8 | 8 | 4 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Length, cm | 35 to 40 | 40 to 45 | 45 to 50 | 50 to 55 | 55 to 60 | 60 to 65 | 65 to 70 | 70 to 75 | over 75 |
|---|---|---|---|---|---|---|---|---|---|
| General population | 32 | 16 | 12 | 12 | 8 | 8 | 4 | 4 | 2 |
| Sensitive population | 12 | 8 | 4 | 4 | 4 | 0 | 0 | 0 | 0 |
| Length, cm | 15 to 20 | 20 to 25 | 25 to 30 | 30 to 35 | 35 to 40 | 40 to 45 | 45 to 50 |
|---|---|---|---|---|---|---|---|
| General population | 16 | 16 | 16 | 16 | 8 | 4 | 4 |
| Sensitive population | 8 | 8 | 8 | 4 | 4 | 0 | 0 |
| Length, cm | 25 to 30 | 30 to 35 | 35 to 40 | 40 to 45 |
|---|---|---|---|---|
| General population | 16 | 12 | 8 | 4 |
| Sensitive population | 4 | 4 | 4 | 0 |
| Length, cm | 35 to 40 | 40 to 45 | 45 to 50 | 50 to 55 |
|---|---|---|---|---|
| General population | 16 | 16 | 12 | 12 |
| Sensitive population | 8 | 4 | 4 | 4 |
Fisheries Management Zone 18
Dalhousie Lake lies in Fisheries Management Zone 18. Ontario sets its fishing seasons and catch limits by zone.
| Species | Open season | Sport licence | Conservation licence |
|---|---|---|---|
| Brook Trout | Open all year | 5 | 2 |
| Brown Trout | Open all year | 5 | 2 |
| Channel Catfish | Open all year | 12 | 6 |
| Crappie | Open all year | 30 | 10 |
| Lake Trout | 4th Sat. in May – Sept. 8 | 2 | 1 |
| Lake Whitefish | Open all year | 12 | 6 |
| Largemouth and Smallmouth Bass or any combination | 3rd Sat. in June – Dec. 15 | 6 | 2 |
| Muskellunge | 1st Sat. in June – Dec. 15 | 1, must be greater than 91 cm (36 in.) | 0 |
| Northern Pike | Jan. 1 – Mar. 31 & 2nd Sat. in May – Dec. 31 | 6 | 2 |
| Pacific Salmon | Open all year | 5 | 2 |
| Rainbow Trout | Open all year | 5 | 2 |
| Splake | Open all year | 5 | 2 |
| Sunfish | Open all year | 300, only 30 may be greater than 18 cm (7.1 in.) | 15 |
| Walleye and Sauger or any combination | Jan. 1 – Mar. 1 & 2nd Sat. in May – Dec. 31 | 4, must be between 40 – 50 cm (15.7 – 19.7 in.) | 2, must be between 40 – 50 cm (15.7 – 19.7 in.) |
| Yellow Perch | Open all year | 50 | 25 |
The figures are the number of fish an angler may catch and keep in a day and have in possession, under a sport fishing licence and under a conservation licence. The rows are the whole zone’s, and they apply to every lake in it. No waterbody exception names Dalhousie Lake.
| Where | Closed |
|---|---|
| Dalhousie Lake and Mississippi River within a 300 m (984 ft.) radius of the bridge of the Twp. road crossing the Mississippi River where it enters Dalhousie Lake – Dalhousie Twp | No fishing from Mar. 1 – Fri. before 2nd Sat. in May |
Dalhousie Lake Ice Fishing
An ice hut on Dalhousie Lake must be removed by March 15. Dalhousie Lake lies in fisheries management zone 18, one of the twenty zones Ontario sets its fishing rules by, and one removal date applies across the whole zone.
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 zone 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 Dalhousie Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.
Islands and names
Official names
Ontario’s geographic names register lists 3 official names on the water and its islands: .
Nearby lakes
- Silver Lake16 km away
- Crotch Lake20 km away
- Christie Lake21 km away
- Palmerston Lake23 km away
Questions about Dalhousie Lake
- How deep is Dalhousie Lake?
Its maximum recorded depth is 18.8 meters.
- How big is Dalhousie Lake?
Its surface covers 6.2 square kilometers, with 16 kilometers of shoreline.
- What fish are in Dalhousie Lake?
Ontario’s aquatic resource records name 28 species, among them walleye, smallmouth bass, largemouth bass, northern pike, lake whitefish and yellow perch.
A print of Dalhousie Lake
Dalhousie Lake has not yet been drawn as a print. The lakes drawn so far are on the lake maps page, and a print of Dalhousie Lake can be requested by email; whether it can be drawn is confirmed before any payment.
Ask about a Dalhousie Lake printLooking at a property on Dalhousie Lake?
Depth and water quality are two records out of many. Our Rural & Cottage Buyer’s Report gathers what the public record holds about one specific address: shore road allowance, road access, wells, flood mapping, Crown land, wetlands and more, read and checked by a person before it is sent.
What these figures do and do not say
- Depth
- A depth reading is the distance from the water surface on the day of survey to the lake bottom. Lake levels vary through the season and between years. The figures for Dalhousie Lake are read from the province’s bathymetry records within the Ontario Hydro Network’s outline of the lake: the deepest figure is the deepest record inside that outline, and the count is every record inside it.
- Shoreline and surface
- The shoreline figure is the length of the mainland shore and of every island shore added together, measured on the Ontario Hydro Network’s outline of the lake. The surface figure is the area of water inside that outline, less the area of its islands. The provincial outline is mapped to within a few meters of the shore, and a shoreline measured from a coarser map comes out shorter, which is why a figure published elsewhere is often lower.
- Survey coverage
- Not every survey covered every arm of a lake, and the province’s index does not always record where a survey ended.
- Water quality
- Each figure belongs to a single monitoring site and not to the lake as a whole. A bay receiving a creek can read differently from open water half a kilometer away. Sites are matched to Dalhousie Lake by name in the province’s records.
- Nearby lakes
- Distances are measured between lake centres.
- Islands and names
- Islands are counted and measured on the Ontario Hydro Network outline; names are the register’s, placed by its own coordinate. The register names islands the outline draws as part of a larger one, and the outline holds islands the register has not named, so the two counts differ. The outline carries some lakes across marsh, so a gap in the marsh is drawn as land, and every such gap is included in the island count. Where the register has not named one and it lies mostly inside a wetland in the province’s Wetland With Significance dataset, the page names the wetland and the table of largest islands leaves it out. Wetland boundaries are mapped at their own scale and can cover a small island whole.
- Location
- Municipal boundaries are read from the province’s records as published and can lag a boundary change.
- Fish
- Ontario’s fish records are compilations of existing knowledge from field biologists and do not represent exhaustive inventories. A species that is not listed was not ruled out. The species list carries one date for the whole record and none for any species.
- Spawning areas
- A spawning area is drawn where the province mapped it, at the province’s stated accuracy, and the record says nothing about how many fish use it in a given year. A nest record is one nest seen on one day; a count of nests is not a count of fish, and a count of records is not a comparison between species. Whether a given piece of work needs an authorization is a determination made by Fisheries and Oceans Canada on the work itself.
- Stocking
- A stocking record is a release on a date. It says nothing about how many fish survived or about the population in the lake today.
- Eating advice
- The guide’s advice is for fish taken from the lake at the tested location and applies to the size classes tested. The province’s guide is the authority and is updated each year.
- Fishing rules
- Seasons and limits are the zone’s, for the year of the dataset the page was built from, and a licence’s own conditions and any waterbody exception apply over them. The province’s regulations summary is the authority.
- Ice hut rules
- Removal dates and registration rules are set by fisheries management zone and change from time to time. The dates here were read from the province in September 2026. The province’s own fishing regulations are the authority.
Where these figures come from
- Depth, shoreline, islands and named places: Ontario Ministry of Natural Resources bathymetry and the Ontario Hydro Network, © King’s Printer for Ontario, Open Government Licence – Ontario.
- Phosphorus and water clarity: Ontario Lake Partner Program, Ministry of the Environment, Conservation and Parks, Open Government Licence – Ontario. Extract built 2026-08-09.
- Aerial photography: Geospatial Ontario imagery, Open Government Licence – Ontario, released collections only.
- Official names: Geographic Names Ontario, Ministry of Natural Resources, Open Government Licence – Ontario. Marinas: Overture Maps Foundation places data, CDLA-Permissive 2.0.
- Lake outline and municipal boundaries: Ontario Hydro Network and Ontario municipal boundary records, Ministry of Natural Resources, Open Government Licence – Ontario.
- Fish species and thermal regime: Ontario Aquatic Resource Area records. Spawning areas: Ontario Fish Activity Area records. Both Ministry of Natural Resources, Open Government Licence – Ontario.
- Stocking: Historical Fish Stocking Data and Fish Stocking Data for Recreational Purposes, Ministry of Natural Resources, Open Government Licence – Ontario.
- Consumption advice: Guide to Eating Ontario Fish advisory database, 2025 edition, Ministry of the Environment, Conservation and Parks, Open Government Licence – Ontario.
- Seasons and limits: Ontario recreational fishing regulations data, Ministry of Natural Resources, Open Government Licence – Ontario.
- Fish plates: Duane Raver, U.S. Fish and Wildlife Service; Ellen Edmonson and Hugh Chrisp, New York State Conservation Department; Timothy Knepp, U.S. Fish and Wildlife Service; U.S. Fish and Wildlife Service. All public domain.
- Ice hut removal dates and registration: Ontario fishing regulations, read September 2026.