Sudbury District, Ontario
Onaping Lake
Four hundred and twenty-six islands and a deepest charted contour of 48.8 meters, from the province's 1974 survey, inside 619 kilometers of shoreline in the District of Sudbury. Stocked with lake trout and walleye by the province nine times between 2017 and 2024.
- Surface
- 66.9 km²
- Shoreline
- 619 km408 mainland + 211 islands
- Islands
- 426
- Charted depth
- 48.8 m
- Depth contours
- 323
All figures are derived from Ontario’s survey records.
Where Onaping Lake is
Onaping Lake lies in the District of Sudbury.
How deep is Onaping Lake?
The deepest mapped contour on Onaping Lake is 48.8 meters, and the water within that boundary descends even farther. Ontario’s bathymetry record holds 323 depth contours for Onaping Lake.
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.
Onaping Lake has 5 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 oligotrophic.
| Site | Location | Years | Last sampled | Classification |
|---|---|---|---|---|
| 4156/2 | Big Water | 5 | 2025 | oligotrophic |
| 4156/1 | near Bannerman Dam | 4 | 2025 | oligotrophic |
The longest record is held by site 4156/2 at Big Water, sampled over 5 springs to 2025. Its long-term mean phosphorus concentration is 7.62 micrograms per litre, within the oligotrophic band, which extends to 10. The site’s 39 clarity readings give a median Secchi depth of 3.6 meters.
Fish in Onaping Lake
Ontario’s aquatic resource records list no species for Onaping Lake. The province’s other records for the lake name eight species, among them walleye, northern pike and burbot. They appear in the records below.
Four of the eight species in the province’s records
Northern Pikepike
Walleyeperch
Smallmouth Basssunfish
Burbotcod
| Family | Species |
|---|---|
| Trout and whitefish | brook trout, lake trout, rainbow trout |
| Pike | muskellunge |
Spawning areas
Ontario maps 2 fish spawning records within the Onaping Lake outline: 2 walleye spawning areas covering 12.93 hectares.
By number of records
By area mapped
- Walleye2 areas12.9 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 Onaping Lake run from 1947 to 2014 and hold 55 releases. Walleye account for most of the fish: 1,476,206 released in ten of the years between 1949 and 2010. The last recorded release was 6,584 lake trout yearlings in 2014.
| Species | Years | Years with a release | Fish released |
|---|---|---|---|
| Walleye | 1949 to 2010 | 10 | 1,476,206 |
| Lake Trout | 1947 to 2014 | 22 | 341,290 |
| Muskellunge | 1968 to 1974 | 3 | 100,000 |
| Smallmouth Bass | 1947 to 1964 | 5 | 25,500 |
| Rainbow Trout | 2009 to 2009 | 1 | 4,283 |
| Brook Trout | 1992 to 1992 | 1 | 500 |
The province’s current stocking programme, recorded from 2017, lists 27,278 lake trout and 10,000 walleye released into Onaping Lake between 2017 and 2024.
Eating the fish
The 2025 Guide to Eating Ontario Fish carries consumption advice for four species taken from Onaping Lake, tested for contaminants at a sampling location in Emo & Fairbairn Twps., Sudbury Dist. 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 | 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 | 12 | 8 | 4 | 4 | 4 | 4 | 4 | 4 | 0 |
| Sensitive population | 8 | 4 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Length, cm | 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 | over 75 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| General population | 16 | 12 | 8 | 8 | 8 | 4 | 4 | 4 | 4 | 4 | 2 |
| Sensitive population | 12 | 4 | 4 | 0 | 0 | 0 | 0 | 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 | 32 | 32 | 16 | 12 | 8 | 4 | 2 |
| Sensitive population | 16 | 12 | 8 | 4 | 0 | 0 | 0 |
| Length, cm | 25 to 30 | 30 to 35 | 35 to 40 | 40 to 45 | 45 to 50 | 50 to 55 |
|---|---|---|---|---|---|---|
| General population | 16 | 12 | 8 | 8 | 4 | 4 |
| Sensitive population | 4 | 4 | 4 | 0 | 0 | 0 |
Fisheries Management Zone 10
Onaping Lake lies in Fisheries Management Zone 10. Ontario sets its fishing seasons and catch limits by zone.
| Species | Open season | Sport licence | Conservation licence |
|---|---|---|---|
| Atlantic Salmon | Jan. 1 – Sept. 30 | 1 | 0 |
| Brook Trout | Jan. 1 – Sept. 30 | 5 | 2 |
| Brown Trout | Open all year | 5 | 2 |
| Channel Catfish | Open all year | 12 | 6 |
| Crappie | Open all year | 30 | 10 |
| Lake Trout | Jan. 1 – Labour Day | 2, not more than 1 greater than 40 cm (15.7 in.) | 1 |
| Lake Whitefish | Open all year | 12 | 6 |
| Largemouth and Smallmouth Bass or any combination | 3rd Saturday in June – November 30 | 6 | 3 |
| Muskellunge | 3rd Sat. in June – Dec. 15 | 1, must be greater than 122 cm (48 in.) | 0 |
| Northern Pike | Open all year | 6; not more than 1 greater than 61 cm, none greater than 86 cm | 2; none greater than 61 cm |
| Pacific Salmon | Open all year | 5 | 2 |
| Rainbow Trout | Open all year | 2 | 1 |
| Splake | Open all year | 5 | 2 |
| Sunfish | Open all year | 50 | 25 |
| Walleye and Sauger or any combination | January 1 to the third Sunday in March and third Saturday in May to December 31 | 4, none greater than 46 cm | 2, none greater than 46 cm |
| 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.
| Species | Open season | Sport licence | Conservation licence |
|---|---|---|---|
| Largemouth and Smallmouth Bass or any combination | Open all year | Zone-wide | Zone-wide |
Where a row reads zone-wide, the zone’s own season or limit above applies.
| Where | Closed |
|---|---|
| Vondet Lake and Vandet Creek – The waters of Vondet Lake and Vandet Creek in the Township of Shelley | No fishing from Mar. 15 – June 15 |
| Muldrew Bay – Onaping Twp | No fishing from Apr. 1 – June 15 |
Onaping Lake Ice Fishing
An ice hut on Onaping Lake must be removed by March 31. Onaping Lake lies in fisheries management zone 10, 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 10 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 Onaping Lake on any given day. Ontario publishes ice safety guidance for anyone going out on the ice, at ontario.ca.
Islands and names
Onaping Lake contains 426 islands in the Ontario Hydro Network’s outline, 21 of them over 10 hectares and 222 under a tenth of a hectare.
| Island | Hectares | |
|---|---|---|
| 1 | unnamed | 680.5 |
| 2 | unnamed | 140.1 |
| 3 | unnamed | 102.3 |
| 4 | unnamed | 101.1 |
| 5 | unnamed | 65.9 |
| 6 | unnamed | 57.3 |
| 7 | unnamed | 54.0 |
| 8 | unnamed | 48.1 |
| 9 | unnamed | 39.0 |
| 10 | unnamed | 34.1 |
Official names
Ontario’s geographic names register lists 12 official names on the water and its islands: six bays and two narrows.
Bays 6
- Arrow Bay
- East Bay
- Green Bay
- Loon Bay
- Muldrew Bay
- Turcotte Bay
Harbours, cuts and narrows 2
- Poplar Narrows
- Three Mile Narrows
Nearby lakes
- Windy Lake51 km away
- Vermilion Lake59 km away
- Fairbank Lake66 km away
- Wanapitei Lake68 km away
Questions about Onaping Lake
- How deep is Onaping Lake?
Its deepest charted contour is 48.8 meters, and the water within it is deeper.
- How big is Onaping Lake?
Its surface covers 66.9 square kilometers and it holds 426 islands. Of its 619 kilometers of shoreline, 408 kilometers is the mainland shore and 211 kilometers is the shore of the islands.
- Is the water clear?
All two monitoring sites with a phosphorus status are classified oligotrophic, the clearest of the province’s three bands.
A print of Onaping Lake
Onaping Lake has not yet been drawn as a print. The lakes drawn so far are on the lake maps page, and a print of Onaping Lake can be requested by email; whether it can be drawn is confirmed before any payment.
Ask about a Onaping Lake printLooking at a property on Onaping 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 depth figure above is the deepest contour charted and is a minimum; the depth within it was not recorded. The figures for Onaping 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 Onaping 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.
- Depth contours
- Each contour is drawn where the survey placed it, at the survey’s own positional accuracy. The survey carries its own shoreline, which differs from the Ontario Hydro Network’s outline, so a contour near the shore can run to or past the outline. Such a stretch is drawn along the outline, as a drawing convention, and is not the survey’s line there. The contour count in the stat band is the province’s, and it includes the survey’s own shoreline contour, one ring around the mainland and one around each charted island, which the map leaves off; the map’s small print gives the split.
- Location
- Municipal boundaries are read from the province’s records as published and can lag a boundary change.
- 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: Ontario Imagery Web Map Service, Open Government Licence – Ontario, drawing this frame from Central Ontario Orthophotography Project 2021, Forest Resources Inventory 2007-2011 and Sentinel 2 2025, satellite.
- 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; 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.