Greenwater Lake

Thunder Bay District, Ontario · MNRF bathymetric survey

54m Mapped depth
177 ft

3,786 ha 54 contours

Paddling Index62MixedMedium confidenceaway from major roads · wooded shoreline

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Depth scale

01112131415154 m

The lake

Survey readout

Greenwater Lake is mapped to a depth of 54 m (177 ft) on the Ontario MNRF survey and covers about 3,786 ha (9,355 acres) in Thunder Bay District, Ontario. Depths come from the Ontario MNRF survey of 1968.

Measured from the Ontario MNRF bathymetry survey.

Deepest mapped contour: 54 m (177 ft)
Survey year: 1968
Surface area: 3,786 ha (9,355 acres)
Shoreline: 64.3 km (40.0 mi) · irregular
Fishing access: No MNRF fishing access point listed within 100 m (the list is incomplete)

Additional depth details54 contours

Contour depths: 0–54 m (177 ft)
Deep-spot markers: 54 m (177 ft), 35 m (115 ft), 35 m (115 ft), 33 m (108 ft), 32 m (105 ft), 31 m (102 ft)

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Location

Thunder Bay District, Ontario · 15 nearest of 285 lakes and 3 rivers · tap a dot to open it

Chart data

Provenance

Sources: Ontario MNRF / LIO Bathymetry, Ontario FRI Leaf-On Imagery, Ontario FRI LiDAR DTM, OpenStreetMap (ODbL), Contains information licensed under the Open Government Licence – Ontario.

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Map details & sources5 sources

All layers registered to one bounding box; positions in WGS 84.

Survey-derived depth contours drape over Ontario LiDAR (FRI DTM) elevation, with a Ontario FRI aerial basemap and OpenStreetMap shoreline. Colour shows surveyed depth; dark lines are the survey's own isobaths.

Coordinates: 48.58149, -90.43058
MNRF lake ID: 15-6904-53837
Vertical exaggeration: 4.22× below the waterline; land at true scale
Basemap: Ontario FRI
Model size: 2.1 MB

Check the source: this lake’s record (15-6904-53837) in the Ontario MNRF bathymetry index, and the contour line layer the map is drawn from (Land Information Ontario open data, Open Government Licence – Ontario). Survey year: 1968. This model was built 2026-09-28. Depths between contours are interpolated, not measured.

Paddling

Paddling Index methodology v1.0 · calculated 2026-09-16

62 / 100MixedData confidence: Medium

Greenwater Lake has a heavily wooded and largely undeveloped setting, long open-water fetch, little nearby major-road exposure.

Why this score?5 components

Included in the index

Component	Rating	Points of weight	Measurement
Natural setting	Excellent	42.4 of 43	98% natural land cover within 150 m of shore (86% forest, 10% wetland; 0% developed)
Geometric wind exposure	Modest	1.9 of 36	mean fetch 6,180 m · 2% of sampled water within 500 m of shelter · long open-water fetch
Motor & speed rules	Not modelled	—	Canada publishes vessel motor and speed restrictions as federal legal schedules, not map data, so they are not part of the Ontario index. Check local signage and Transport Canada rules before going out.
Public access	Not listed	—	No publicly listed MNRF fishing access point within 100 m of this shoreline. Municipal, private and informal launches are not all in this source, so this is not evidence that access is poor — the component is excluded and the remaining weights are renormalized.
Road isolation	Excellent	18.1 of 21	relatively isolated from major roads · 4 Ontario Road Network segments within 1.2 km (traffic estimated from road class, not measured)

Additional paddling considerations

These describe the lake but are not part of the v1 Paddling Index and do not change the number above.

Wake sensitivity: Low — wide enough that wakes disperse over most of the lake
Observed motorized activity: Unknown — No lake-level measurement of boat traffic is available. Legal permission to operate motors is not evidence of use.
Wildlife habitat potential: High — 86% forest and 10% wetland cover within 150 m of shore
Mapped wildlife habitat: Mapped — Ontario MNRF has mapped moose aquatic feeding areas within 1 km of this lake. These are habitat records from provincial surveys, not animal counts; areas with nothing mapped may still hold wildlife. · Ontario MNRF Wildlife Values Area. Contains information licensed under the Open Government Licence – Ontario.

Compare Ontario lakes by Paddling Index →

How this index is calculated. The Paddling Index is a relative composite derived from lake geometry and public land-cover, access and road-network data. It is not a user review, a safety rating, or a prediction of an individual outing. Differences of a few points should not be treated as meaningful — an 84 and an 82 are broadly comparable. Components and weights for Ontario lakes: natural setting 35%, geometric wind exposure 29%, public access 18%, road isolation 18%. Motor and speed restrictions are not modelled for Ontario, and road traffic is estimated from road class, not measured. Where a component has no data the remaining weights are renormalized and the confidence rating is lowered; below Medium confidence no number is shown. Ontario scores are relative to other Ontario lakes and are not directly comparable with Paddling Index scores on our sister sites, which use different data sources and include a watercraft-rules component. Sources: Ontario MNRF bathymetry outline (0 m contour or survey index polygon), Ontario Land Cover v1.0, Ontario MNRF (Open Government Licence – Ontario) (2020) and Ontario Road Network (Open Government Licence – Ontario); traffic estimated by road class, not measured (2026-09). Conditions change quickly — check current weather and local conditions before going out.

Angler catch reports

Fish ON-Line · 2016

One angler has logged a trip here: 8 lake trout, fished through the ice, in February 2016.

Lake Trout

Pictures are sized relative to each other. Illustrations are AI-generated representative adults in everyday colours, not photographs (provenance).

This is a single angler’s report — a snapshot of one trip, not a picture of the whole lake.

About these fish → the Fish of Ontario guide

Trips are logged voluntarily by anglers in Ontario’s Fish ON-Line app. This is what people report catching, not a Ministry survey, and a species nobody has logged may still be here. Contains information licensed under the Open Government Licence – Ontario. Source: Ontario Ministry of Natural Resources, Fish ON-Line. A logged catch does not mean it is legal to catch or keep: check the Ontario Fishing Regulations Summary for this lake’s zone and exceptions.

Quick answers

Greenwater Lake — common questions

How deep is Greenwater Lake?

The deepest contour on the Ontario MNRF bathymetric survey of Greenwater Lake is 54 m (177 ft). That is the deepest depth the historical survey map records, which may differ from the deepest point of the lake itself.

How big is Greenwater Lake?

Greenwater Lake covers about 3,786 ha (9,355 acres) in Thunder Bay District, Ontario.

Is there public access to Greenwater Lake?

No fishing access point for Greenwater Lake appears in the Ontario MNRF fishing access point list (within 100 m of the shoreline). That is not the same as the lake being private -- the MNRF list is incomplete, and many municipal, marina and private launches are not in it.

More lakes in Thunder Bay District