Lake Seneca (Ontario): Depth Map, Fishing & Water Quality

Map of Lake Seneca — Lake Seneca
43.9593° N, 79.5208° W

Shoreline and neighbouring water from open government data.

Download the map (SVG)

Lake Seneca, Ontario. 43.9593° N, 79.5208° W

Not for navigation. Depths are from government surveys and may be outdated.

borealbound.ca/lakes/on/lake-seneca/, compiled October 9, 2026

Canadian Geographical Names Database, Natural Resources Canada. Contains information licensed under the Open Government Licence – Canada.
HydroLAKES v1.0, Messager et al. 2016 / WWF HydroSHEDS. Licensed under CC BY 4.0.
Census boundaries and population, 2021, Statistics Canada. Adapted from Statistics Canada. This does not constitute an endorsement by Statistics Canada.
Aquatic Resource Area survey points, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
Fisheries Management Zones, Ontario Ministry of Natural Resources. Contains information licensed under the Open Government Licence – Ontario.
Lake Partner Program, Ontario Ministry of the Environment, Conservation and Parks. Contains information licensed under the Open Government Licence – Ontario.
City page weather forecasts and alerts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
Air Quality Health Index observations and forecasts, Environment and Climate Change Canada. Contains data from Environment and Climate Change Canada (ECCC Data Servers End-use Licence).
Guide to Eating Ontario Fish: Advisory Database, Ontario Ministry of the Environment, Conservation and Parks. Contains information licensed under the Open Government Licence – Ontario.
Photographs, Wikimedia Commons contributors. Each photo carries its own licence (CC0, public domain, CC BY or CC BY-SA), credited where shown.

Lake Seneca covers 0.26 km², making it smaller than 71% of the 18,731 lakes in Ontario. It lies beside Eversley.

Government surveys have recorded 14 fish species here, including pumpkinseed, bluegill and largemouth bass.

Area: 0.26 km²; smaller than 71% of the 18,731 lakes in Ontario
Shoreline: 4.9 km; shorter than 52% of the 18,731 lakes in Ontario
Water clarity: 3.2 mSecchi depth, 2013; less clear than 58% of the 1,251 monitored lakes in Ontario
Fish species: 14; more than 86% of the 2,454 surveyed lakes in Ontario
Elevation: 294 m

Today on the water

8.1 °C

Wind WNW 6 km/h

Observed at Richmond Hill, as of 3:00 a.m. EDT

choppy Estimated waves, next 12 hours: up to 0.2 m. Around 12 p.m., wind from the northwest: the northwest shore is sheltered, waves build toward the southeast shore.

Hourly forecast, next 24 hours
Time	4 a.m.	7 a.m.	10 a.m.	1 p.m.	4 p.m.	7 p.m.	10 p.m.	1 a.m.
Wind km/h	W 15	W 15	W 15	NW 30	NW 30	NW 15	var. 5	var. 5
Gusts km/h				50	50
Waves (est.) m	0.1	0.1	0.1	0.2	0.2
Temp. °C	5	7	11	16	18	14	9	6
Precip. %	20	40	40	40	20	20	0	0

Tonight: Partly cloudy with 40 percent chance of showers this evening. Clearing overnight. Wind northwest 30 km/h gusting to 50 becoming light this evening. Low plus 5.

Weather: Richmond Hill (local forecast), as of 3:03 a.m. EDT

Sun and moon

Civil dawn: 6:56 a.m.
Sunrise: 7:25 a.m.
Sunset: 6:44 p.m.
Civil dusk: 7:13 p.m.
Moonrise: 6:17 a.m.
Moonset: 6:03 p.m.
Moon: Waning crescent, 1% lit

Air Quality Health Index

1 low risk

Newmarket, as of 3:00 a.m. EDT

Follow this lake by email: a weekly summary of conditions.

Fish

Sport fish by the share of the 10 government surveys (1400–2004) that recorded them.

Pumpkinseed10 of 10
Bluegill9 of 10
Largemouth Bass9 of 10
Yellow Perch9 of 10
Black Crappie7 of 10
Walleye4 of 10
Rock Bass1 of 10Not recorded since 1968
Smallmouth Bass1 of 10Not recorded since 1400

Forage fish and other species (6)

Forage fish

Golden Shiner 8
Iowa Darter 3
Johnny Darter 1

Other

Common Carp 9
White Sucker 8
Brown Bullhead 3

Numbers are the surveys that recorded each species.

Eating your catch

The provincial guide to eating fish (2026) sets limits for 1 species from Lake Seneca. Maximum meals per month:

Species	Length	General population	Sensitive population*	Contaminant
Common Carp	55-60 cm	16	16	Precautionary

* As defined in the guide, including children and people who are or may become pregnant. Limits are for the length the guide lists most often; they change with the size of the fish. Read the official guide

Fishing regulations: Fisheries Management Zone 16. Check seasons and limits before you fish.