Eutrophic Lakes in Ontario

194 eutrophic lakes in Ontario. High nutrients, frequent algae, reduced clarity.

A eutrophic lake is a productive ecosystem with the trade-offs that come with productivity: more food at the base of the food web, more clarity reduction by mid-summer, more dissolved-oxygen variability near the bottom. 194 Ontario lakes register as eutrophic. Only 0% are deep — eutrophy correlates with shallowness, agricultural watersheds, and the kind of nutrient-input history that takes decades to shift.

Eutrophic lakes typically grade C or D on the LakeGrade rubric. The same nutrient richness that defines the trophic class drives the lower grade.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Home Lake	Parry Sound District	B	-	-	51
2	Moose Lake	Cochrane District	B	-	-	53
3	Gibson Lake	Peel Region	B	-	-	51
4	Mccharles Lake	Sudbury District	B	-	-	53
5	Barnston Lake	Kenora District	B	-	-	51
6	Bruce Lake	Kenora District	B	-	-	52
7	Pine Lake	Haliburton	B	-	-	53
8	Montreuil Lake	Cochrane District	B	-	-	51
9	Apungsisagen Lake	Rainy River District	B	5.2 ft	-	50
10	D'Amour Lake	Cochrane District	B	3.9 ft	-	52
11	Dora Lake	Cochrane District	B	3.9 ft	-	52
12	Kamiskotia Lake	Cochrane District	B	4.3 ft	-	51
13	Long Lake	Timiskaming District	B	3.9 ft	-	50
14	Lower Deception Lake	Cochrane District	B	4.1 ft	-	52
15	Neilson Lake	Muskoka District	B	4.9 ft	-	51
16	Off Lake	Rainy River District	B	4.6 ft	-	51
17	Ryde Lake	Muskoka District	B	4.9 ft	-	50
18	Sand Lake	Kenora District	B	7.5 ft	-	50
19	Sandy Lake	Kenora District	B	4.4 ft	-	50
20	Schnarr Lake	Kenora District	B	4.9 ft	-	51
21	Stoneleigh Lake	Muskoka District	B	3.9 ft	-	51
22	Farley Lake	Rainy River District	B	3.6 ft	-	51
23	Favell Lake	Cochrane District	B	3.9 ft	-	52
24	Gooch L. Lake	Kenora District	B	4.6 ft	-	51
25	Kapuskasing Lake	Algoma District	B	4.3 ft	-	51
26	Marks Lake	Thunder Bay District	B	3.9 ft	-	51
27	Little Vermilion Lake	Kenora District	B	4.3 ft	-	52
28	Mickle Lake	Kenora District	B	3.9 ft	-	52
29	Nikip Lake	Kenora District	B	4.9 ft	-	50
30	Obj. Id (Grassy Lake	Cochrane District	B	3.9 ft	-	52
31	Red Lake	Nipissing District	B	4.6 ft	-	50
32	Rugby Lake	Kenora District	B	3.4 ft	-	53
33	Spruce Lake	Kenora District	B	4.6 ft	-	50
34	Young Lake	Thunder Bay District	B	3.6 ft	-	52
35	Alcock Lake	Kenora District	C	3.9 ft	-	54
36	Bass Lake	Muskoka District	C	5.9 ft	-	51
37	Beaverkit Lake	Thunder Bay District	C	2.6 ft	-	51
38	Belwood Lake	Wellington	C	4.6 ft	-	52
39	Bowley Lake	Lanark	C	4.4 ft	-	54
40	Brandy Lake	Muskoka District	C	3.6 ft	-	55
41	Caliper Lake	Kenora District	C	4.9 ft	-	52
42	Clark Lake	Muskoka District	C	3.3 ft	-	51
43	Cloud Lake	Thunder Bay District	C	4.3 ft	-	53
44	Cushing Lake	Thunder Bay District	C	3.8 ft	-	53
45	Delaney Lake	Nipissing District	C	3.9 ft	-	55
46	Departure Lake	Cochrane District	C	3 ft	-	52
47	Doe Lake	Muskoka District	C	5.6 ft	-	52
48	Dog Lake	Frontenac	C	6.2 ft	-	52
49	Fletchers Lake	Cochrane District	C	3 ft	-	54
50	Grassy Lake	Kenora District	C	5.6 ft	-	51
51	Lac des Mille Lacs Lake	Thunder Bay District	C	4.3 ft	-	53
52	Lake Adele	Parry Sound District	C	6.1 ft	-	50
53	Lake Seymour	Northumberland	C	5.6 ft	-	51
54	Lena Lake	Kenora District	C	4.9 ft	-	51
55	Lillabelle Lake	Cochrane District	C	4.9 ft	-	52
56	Little Cranberry Lake	Leeds and Grenville Counties	C	8.2 ft	-	53
57	Little Lake	Bruce	C	5.7 ft	-	52
58	Mercer Lake	Nipissing District	C	4.6 ft	-	52
59	Minnow Lake	Sudbury District	C	4.3 ft	-	53
60	Muskrat Lake	Renfrew	C	5.9 ft	-	52
61	Nighthawk Lake	Cochrane District	C	-	-	63
62	Onawa Lake	Muskoka District	C	2.3 ft	-	56
63	Pot Lake	Frontenac	C	3.6 ft	-	56
64	Puslinch Lake	Wellington	C	1 ft	-	61
65	Rice Lake	Peterborough	C	5.1 ft	-	52
66	Robinson Lake	Sudbury District	C	4.3 ft	-	54
67	South Lake	Leeds and Grenville Counties	C	4.9 ft	-	53
68	Three Mile Lake	Muskoka District	C	5.2 ft	-	51
69	Troy Lake	Leeds and Grenville Counties	C	5.6 ft	-	51
70	Wabigoon Lake	Kenora District	C	3.4 ft	-	56
71	Wagner Lake	Durham Region	C	5.4 ft	-	52
72	West Little Lake	Bruce	C	3 ft	-	51
73	Whitney Lake	Kenora District	C	5.6 ft	-	50
74	Wildwood Lake	Perth	C	4.9 ft	-	53
75	Banister Pond	Northumberland	C	-	-	62
76	Mud Lake	Sudbury District	C	-	-	58
77	Rainy River Lake	Rainy River District	C	-	-	60
78	Shadow Lake	Peterborough	C	-	-	59
79	Bottle Bay Lake	Kenora District	C	-	-	54
80	Cul de Sac Lake	Kenora District	C	-	-	57
81	Kelly Lake	Sudbury District	C	-	-	60
82	Berens Lake	Kenora District	C	3.4 ft	-	55
83	Blueberry Lake	Kenora District	C	4.9 ft	-	53
84	Captain Tom Lake	Rainy River District	C	5.6 ft	-	51
85	Carl Wilson L. Lake	Nipissing District	C	2 ft	-	51
86	Cygnet Lake	Kenora District	C	6.6 ft	-	51
87	Dinorwic Lake	Kenora District	C	3.3 ft	-	53
88	Doehead Lake	Algoma District	C	12.5 ft	-	53
89	Giroux Lake	Parry Sound District	C	3.3 ft	-	52
90	Humestone Lake	Cochrane District	C	3 ft	-	54
91	Kenogamisis Lake	Thunder Bay District	C	3.3 ft	-	52
92	Kesagami Lake	Cochrane District	C	2.3 ft	-	55
93	Labyrinth Lake	Timiskaming District	C	5.9 ft	-	51
94	Lowry Lake	Rainy River District	C	4.9 ft	-	52
95	Oke Lake	Cochrane District	C	3.3 ft	-	52
96	Puslinch Lake	Wellington	C	6.2 ft	-	52
97	Saunders Lake	Nipissing District	C	4.9 ft	-	53
98	Upper Slate Lake	Kenora District	C	3.3 ft	-	51
99	Upper Sturgeon Lake	Sudbury District	C	1.6 ft	-	57
100	Wasaw Lake	Rainy River District	C	4.9 ft	-	53

All eutrophic lakes →Minnesota version →Wisconsin version →Illinois version →Michigan version →Iowa version →Ohio version →Pennsylvania version →New York version →Missouri version →Indiana version →North Dakota version →South Dakota version →Florida version →Colorado version →North Carolina version →Vermont version →Texas version →Oregon version →Arkansas version →Oklahoma version →Kansas version →Nebraska version →Nevada version →Arizona version →Idaho version →Montana version →New Mexico version →Tennessee version →Alabama version →Virginia version →Kentucky version →Utah version →Washington version →Wyoming version →Georgia version →Massachusetts version →Québec version →All Ontario lakes →

Source: EPA National Aquatic Resource Surveys, 2026.