Eutrophic Lakes in Wisconsin

487 eutrophic lakes in Wisconsin. 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. 487 Wisconsin 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	Boot Lake	Vilas	B	-	-	50
2	Big Twin Lake	Waushara	B	-	-	52
3	Unnamed Lake	Douglas	B	-	-	52
4	Unnamed Lake	Washburn	B	-	-	52
5	Okauchee Lake-Site No. 1-Near Okauchee	Waukesha	B	-	-	52
6	L St Germain Lk Site K @ S. Bay Lake	Vilas	B	-	-	52
7	Lk Superior Lake	Douglas	B	-	-	53
8	Little Wood Lake	Burnett	B	-	-	51
9	Delavan Lake	Walworth	B	-	-	51
10	Dunes Lake Just Us of Outlet	Door	B	-	-	50
11	Inlet To Dunes Lake	Door	B	-	-	53
12	East Wetland Inlet To Lake Ree	Bayfield	B	-	-	52
13	Indian School Lake	Sawyer	B	-	-	50
14	Wiley Lake	Bayfield	B	-	-	52
15	Chippewa Flowage Lake	Sawyer	B	6.9 ft	-	50
16	Lawrence Lake	Marquette	B	6.7 ft	-	50
17	Rush Lake	Vilas	B	5 ft	-	51
18	Crescent Lake	Polk	B	4.5 ft	-	50
19	Eagle Spring Lake	Waukesha	B	4.3 ft	-	51
20	East Twin Lake	Marquette	B	3.3 ft	-	53
21	Hiawatha Lake	Vilas	B	4 ft	-	52
22	Shoe Lake	Manitowoc	B	7 ft	-	50
23	Black Brook Flowage Lake	Polk	B	10.5 ft	-	51
24	Clarey Lake	Polk	B	4.3 ft	-	51
25	Van Zile Lake	Forest	B	5.4 ft	-	50
26	Black Hawk Lake	Iowa	B	5 ft	-	51
27	Patrick Lake	Adams	B	5 ft	-	50
28	Clay Lake	Bayfield	B	3.5 ft	-	52
29	Mckenzie Lake	Polk	B	7 ft	-	50
30	Lake Thirty	Barron	B	4.8 ft	-	51
31	Cruson Slough Lake	Richland	B	7.6 ft	-	50
32	Gaslyn Lake	Burnett	C	4.5 ft	-	51
33	Chippewa Flowage -Pokegema Lake	Sawyer	C	5.8 ft	-	51
34	Quarry Lake	Brown	C	8 ft	-	52
35	Delavan Lake	Walworth	C	10 ft	-	55
36	Boulder Lake	Vilas	C	5.6 ft	-	50
37	Fuller Lake	Oneida	C	4.3 ft	-	53
38	Pickerel Lake	Vilas	C	6 ft	-	50
39	Pickerel Lake	Oconto	C	4.5 ft	-	54
40	Grignon Lake	Oconto	C	6 ft	-	50
41	Round Lake	Price	C	4 ft	-	54
42	Round Lake	Oneida	C	4.4 ft	-	52
43	Rice Lake	Iron	C	5 ft	-	52
44	Rice Lake	Polk	C	4.5 ft	-	53
45	Townline Lake	Oneida	C	6.4 ft	-	52
46	Indian Lake	Oneida	C	-	-	55
47	Milwaukee Harbor Lake	Milwaukee	C	8.2 ft	-	52
48	Long Lake	Polk	C	5.9 ft	-	51
49	Long Lake	Polk	C	5 ft	-	53
50	Long Lake	Shawano	C	6 ft	-	50
51	Long Lake	Sauk	C	4.1 ft	-	54
52	Birch Lake	Washburn	C	5.5 ft	-	52
53	Nelson Lake	Sawyer	C	5 ft	-	52
54	Dog Lake	Oneida	C	3.9 ft	-	54
55	Rock Lake	Vilas	C	6.2 ft	-	51
56	North Lake	Barron	C	5.5 ft	-	51
57	Pike Lake	Marathon	C	5 ft	-	53
58	Red Cedar Lake	Jefferson	C	4.3 ft	-	53
59	Delavan Lake	Walworth	C	8 ft	-	54
60	Lac Vieux Desert Lake	Vilas	C	5.7 ft	-	52
61	Cochran Lake	Vilas	C	6 ft	-	52
62	Green Lake	Sawyer	C	4.7 ft	-	53
63	Green Lake	Green Lake	C	11.5 ft	-	53
64	Mann Lake	Vilas	C	6.8 ft	-	52
65	Mud Lake	Polk	C	4.3 ft	-	53
66	Deer Lake	Oneida	C	4 ft	-	54
67	Duck Lake	Langlade	C	3.5 ft	-	56
68	Loon Lake	Shawano	C	5.5 ft	-	50
69	Big Arbor Vitae Lake	Vilas	C	6 ft	-	51
70	Little Sand Lake	Barron	C	5 ft	-	53
71	Bearskin Lake	Oneida	C	6 ft	-	51
72	White Lake	Waupaca	C	5.6 ft	-	50
73	Stella Lake	Vilas	C	5 ft	-	53
74	Lake Esadore	Taylor	C	4.5 ft	-	52
75	Amnicon Lake	Douglas	C	5 ft	-	52
76	Ward Lake	Polk	C	6 ft	-	50
77	Druid Lake	Washington	C	5.5 ft	-	51
78	Diamond Lake	Oneida	C	3.5 ft	-	55
79	Whitewater Lake	Walworth	C	4 ft	-	54
80	Big Dardis Lake	Price	C	5.5 ft	-	50
81	Laurel Lake	Oneida	C	3.7 ft	-	54
82	School Section Lake	Waukesha	C	6.2 ft	-	51
83	School Section Lake	Waupaca	C	6.5 ft	-	50
84	Big Trade Lake	Burnett	C	5 ft	-	53
85	Wood Lake	Burnett	C	5.5 ft	-	51
86	Hancock Lake	Oneida	C	5.4 ft	-	52
87	Deep Hole Lake	Langlade	C	9 ft	-	51
88	Deep Hole Lake	Oneida	C	4.3 ft	-	52
89	Black Oak Lake	Langlade	C	4.3 ft	-	54
90	White Mound Lake	Sauk	C	5 ft	-	53
91	Random Lake	Sheboygan	C	4.5 ft	-	52
92	Baker Lake	Vilas	C	4.5 ft	-	54
93	Shawano Lake	Shawano	C	5.8 ft	-	52
94	Chute Pond at	Oconto	C	6 ft	-	52
95	Big Stone Lake	Oneida	C	4.2 ft	-	53
96	Wiscobee Lake	Oconto	C	5.7 ft	-	50
97	Pine Lake	Forest	C	4.8 ft	-	53
98	Moon Lake	Barron	C	-	-	57
99	Milwaukee Harbor Lake	Milwaukee	C	8.2 ft	-	52
100	Chippewa Flowage -North of Cranberry Bars Lake	Sawyer	C	4.9 ft	-	55

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

Source: EPA National Aquatic Resource Surveys, 2026.