Hypereutrophic Lakes in Minnesota

160 hypereutrophic lakes in Minnesota. Very high nutrients, dense algae, poor clarity.

Hypereutrophic lakes (TSI above 70) are at the upper end of the productivity scale: visible algal blooms most weeks of summer, clarity often under 3 feet, and meaningful risk of harmful-algal-bloom toxin events. 160 hypereutrophic lakes are on the Minnesota books. Almost none of them are deep — 0% break 50 feet. Shallow basin plus heavy nutrient input is the consistent recipe.

Hypereutrophic lakes overwhelmingly grade D or F — the trophic class and the grade are measuring closely-related dimensions of the same underlying nutrient regime.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Ann Lake	Pope	D	8.4 ft	-	70
2	Mud Lake	Otter Tail	D	1.3 ft	-	71
3	Unnamed Lake	Wright	D	1.3 ft	-	70
4	Star Lake	Meeker	D	1 ft	-	71
5	Ann Lake	Wright	D	3.7 ft	-	71
6	Brownie Lake	Hennepin	D	4.8 ft	-	83
7	Swartout Lake	Wright	D	5.2 ft	-	75
8	Winsted Lake	McLeod	D	3.3 ft	-	76
9	Porter Lake	Blue Earth	D	1.3 ft	-	71
10	Mud Lake	Hennepin	F	0.9 ft	-	77
11	Mud Lake	Hennepin	F	3 ft	-	71
12	Pike Lake	Scott	F	2 ft	-	73
13	Long Lake	Stearns	F	2.5 ft	-	76
14	Long Lake	Cottonwood	F	1 ft	-	77
15	Unnamed Lake	Ramsey	F	1 ft	-	78
16	Unnamed Lake	Meeker	F	0.7 ft	-	83
17	Unnamed Lake	Benton	F	1.5 ft	-	71
18	Unnamed Lake	Becker	F	1.2 ft	-	75
19	Unnamed Lake	Otter Tail	F	1.3 ft	-	73
20	Unnamed Lake	Big Stone	F	2 ft	-	81
21	Unnamed Lake	Stevens	F	1.1 ft	-	75
22	Unnamed Lake	Swift	F	0.7 ft	-	83
23	Unnamed Lake	Watonwan	F	1 ft	-	81
24	Unnamed Lake	Grant	F	0.7 ft	-	84
25	Unnamed Lake	Brown	F	0.3 ft	-	100
26	Unnamed Lake	Hennepin	F	-	-	82
27	Jonathan Lake	Carver	F	1.5 ft	-	74
28	Peltier Lake	Anoka	F	2 ft	-	78
29	Tetonka Lake	Le Sueur	F	3 ft	-	75
30	Wakanda Lake	Kandiyohi	F	0.5 ft	-	87
31	Saint Johns Lake	Kandiyohi	F	0.5 ft	-	83
32	Clear Lake	Brown	F	0.8 ft	-	77
33	Clear Lake	Waseca	F	2.5 ft	-	70
34	Clear Lake	Stevens	F	0.7 ft	-	85
35	Eagle Lake	Carver	F	2.3 ft	-	71
36	Eagle Lake	Blue Earth	F	1 ft	-	77
37	Fish Lake	Becker	F	1 ft	-	76
38	Wheeler North Lake	Kandiyohi	F	1 ft	-	82
39	Union Lake	Rice	F	3 ft	-	84
40	Allie Lake	Renville	F	2 ft	-	75
41	Roberds Lake	Rice	F	2 ft	-	78
42	Charlotte Lake	Stevens	F	0.9 ft	-	81
43	Island Lake	Lyon	F	2 ft	-	70
44	Rice Lake	Hennepin	F	2 ft	-	78
45	Pokegama Lake	Pine	F	2 ft	-	73
46	George Lake	Martin	F	1.6 ft	-	74
47	Ox Yoke Lake	Hennepin	F	2.6 ft	-	77
48	Silver Lake	Mille Lacs	F	1 ft	-	77
49	Big Woods Lake	Carver	F	1 ft	-	79
50	Goose Lake	Ramsey	F	0.7 ft	-	80
51	Goose Lake	Carver	F	1 ft	-	76
52	Goose Lake	Goodhue	F	0.4 ft	-	80
53	Goose Lake	Hennepin	F	0.8 ft	-	77
54	Typo Lake	Anoka	F	1 ft	-	77
55	Powderhorn Lake	Hennepin	F	1.3 ft	-	75
56	Fountain Lake	Wright	F	1 ft	-	76
57	Fountain Lake	Freeborn	F	1.5 ft	-	71
58	Crystal Lake	Blue Earth	F	1.5 ft	-	75
59	Benton Lake	Carver	F	0.8 ft	-	80
60	Foster Lake	Wright	F	1.6 ft	-	75
61	Knife Lake	Kanabec	F	2.3 ft	-	71
62	Diamond Lake	Hennepin	F	1.4 ft	-	75
63	Ardmore Lake	Hennepin	F	1.6 ft	-	80
64	Uhl Lake	Wright	F	1 ft	-	77
65	Schultz Lake	Kandiyohi	F	1.6 ft	-	75
66	Alice Lake	Otter Tail	F	0.5 ft	-	87
67	Cornelia Lake	Hennepin	F	0.8 ft	-	77
68	Wood Lake	Yellow Medicine	F	3 ft	-	72
69	Arvilla Lake	Meeker	F	1 ft	-	76
70	Vadnais Lake	Ramsey	F	1 ft	-	74
71	Langdon Lake	Hennepin	F	1.5 ft	-	71
72	Circle Lake	Rice	F	1.5 ft	-	82
73	Little Rock Lake	Benton	F	2 ft	-	72
74	Hanska Lake	Brown	F	1 ft	-	78
75	Cleary Lake	Scott	F	2.3 ft	-	72
76	Hazeltine Lake	Carver	F	1 ft	-	77
77	Loon Lake	Jackson	F	0.9 ft	-	82
78	Loon Lake	Waseca	F	2 ft	-	70
79	Sylvan Lake	Hennepin	F	1.1 ft	-	81
80	Cameron Lake	Polk	F	1 ft	-	76
81	Miller Lake	Carver	F	1.6 ft	-	76
82	Mcknight Lake	Carver	F	2.3 ft	-	71
83	Lost Lake	Hennepin	F	1.5 ft	-	73
84	Parley Lake	Carver	F	1.6 ft	-	70
85	Spring Lake	Hennepin	F	3.1 ft	-	93
86	Wheeler South Lake	Kandiyohi	F	2 ft	-	70
87	Chub Lake	Dakota	F	0.5 ft	-	87
88	Amber Lake	Martin	F	2 ft	-	72
89	Swede Lake	Carver	F	2.3 ft	-	70
90	Augusta Lake	Dakota	F	-	-	80
91	Muewissen Lake	Carver	F	1.6 ft	-	73
92	Malmedal Lake	Pope	F	1 ft	-	80
93	Indianhead Lake	Hennepin	F	1.6 ft	-	71
94	Simon Lake	Pope	F	1.3 ft	-	73
95	Edina Lake	Hennepin	F	0.8 ft	-	77
96	Dean Lake	Wright	F	2.6 ft	-	75
97	Lower Orono Lake	Sherburne	F	2.3 ft	-	71
98	Hope Lake	Meeker	F	2 ft	-	73
99	Unn Lake	Hennepin	F	2.5 ft	-	75
100	Unn Pond	Dakota	F	2 ft	-	71

All hypereutrophic lakes (MN+WI) →Wisconsin version →All Minnesota lakes →

Source: EPA National Aquatic Resource Surveys, 2026.