Hypereutrophic Lakes in Idaho

26 hypereutrophic lakes in Idaho. 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. 26 hypereutrophic lakes are on the {{stateName}} 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	Nla Lake	Idaho	B	19.2 ft	-	76
2	Nla Lake	Washington	B	15.1 ft	-	72
3	Nla Lake	Shoshone	B	22.1 ft	-	76
4	Nla Lake	Bonner	C	8.4 ft	-	79
5	Nla Lake	Kootenai	C	6.9 ft	-	77
6	Nla Lake	Valley	C	7.7 ft	-	83
7	Nla Lake	Blaine	C	7.9 ft	-	84
8	Nla Lake	Bonner	C	8.2 ft	-	88
9	Nla Lake	Bonner	C	-	-	100
10	Nla Lake	Nez Perce	C	7.5 ft	-	87
11	Nla Lake	Valley	C	4.4 ft	-	88
12	Nla Lake	Bonner	D	6.5 ft	-	87
13	Nla Lake	Ada	D	1.3 ft	-	101
14	Nla Lake	Twin Falls	D	5.6 ft	-	92
15	Nla Lake	Idaho	D	2 ft	-	92
16	Nla Lake	Owyhee	D	5.2 ft	-	91
17	Mann Creek Reservoir	Washington	D	-	-	72
18	Nla Lake	Latah	D	3.4 ft	-	96
19	Nla Lake	Owyhee	D	0.7 ft	-	107
20	Nla Lake	Fremont	D	3.4 ft	-	96
21	Nla Lake	Elmore	D	3.4 ft	-	97
22	Nla Lake	Bear Lake	F	3.3 ft	-	100
23	Nla Lake	Camas	F	5.2 ft	-	71
24	Nla Lake	Camas	F	0.8 ft	-	123
25	Nla Lake	Owyhee	F	0.7 ft	-	113
26	Mpipeline Rd Lake	Owyhee	F	-	-	131

All hypereutrophic 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 →Montana version →New Mexico version →Tennessee version →Alabama version →Virginia version →Kentucky version →Utah version →Washington version →Wyoming version →All Idaho lakes →

Source: EPA National Aquatic Resource Surveys, 2026.