Eutrophic Lakes in Colorado

41 eutrophic lakes in Colorado. 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. 41 {{stateName}} 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	Windy Gap Reservoir	Grand	B	-	-	51
2	Willow Creek Reservoir	Grand	C	3.9 ft	-	55
3	Stagecoach Reservoir	Routt	C	7.5 ft	-	54
4	Upper Ned Wilson Lake	Rio Blanco	C	-	-	61
5	Chatfield Reservoir	Jefferson	D	6.2 ft	-	51
6	Deweese Reservoir	Custer	D	5.2 ft	-	53
7	Lon Hagler Reservoir	Larimer	D	4.6 ft	-	55
8	Chambers Lake	Larimer	D	5.1 ft	-	54
9	Boyd Lake	Larimer	D	4.6 ft	-	55
10	Douglas Reservoir	Larimer	D	4.1 ft	-	57
11	Timnath Reservoir	Larimer	D	5.6 ft	-	52
12	Beaver Creek Reservoir	Rio Grande	D	6.2 ft	-	51
13	Eggleston Lake	Delta	D	4.9 ft	-	54
14	Lake Isabel	Custer	D	5.9 ft	-	52
15	Barr Lake	Adams	D	3.9 ft	-	58
16	Bluff Lake	Denver	D	4.7 ft	-	55
17	Stalker Lake	Yuma	D	6 ft	-	51
18	Vega Reservoir	Mesa	D	3.9 ft	-	57
19	Trinidad Reservoir	Las Animas	D	6.6 ft	-	50
20	Sweitzer Reservoir	Delta	D	3.6 ft	-	59
21	Kenney Reservoir	Rio Blanco	D	6 ft	-	51
22	Big Creek Reservoir	Mesa	D	3.4 ft	-	59
23	Crawford Reservoir	Delta	D	5.6 ft	-	52
24	Horseshoe Reservoir	Huerfano	D	3.9 ft	-	57
25	Road Canyon Reservoir	Hinsdale	D	5.6 ft	-	52
26	Martin Lake	Huerfano	D	4.8 ft	-	55
27	Steamboat Lake	Routt	D	6.6 ft	-	50
28	Elkhead Reservoir	Moffat	D	5.2 ft	-	53
29	Windsor Lake	Weld	F	2 ft	-	67
30	Prospect Lake	El Paso	F	1.6 ft	-	70
31	Jackson Reservoir	Morgan	F	2.1 ft	-	66
32	Union Reservoir	Weld	F	3.2 ft	-	60
33	Jumbo Reservoir	Logan	F	2.1 ft	-	66
34	Prewitt Reservoir	Washington	F	1.8 ft	-	69
35	Highline Lake	Mesa	F	3 ft	-	62
36	Equestrian Park Pond	Douglas	F	3 ft	-	62
37	John Martin Reservoir	Bent	F	3.1 ft	-	61
38	Lake Meredith	Crowley	F	1.6 ft	-	70
39	Miramonte Reservoir	San Miguel	F	2.8 ft	-	62
40	Adobe Creek Reservoir	Kiowa	F	1.7 ft	-	69
41	Milton Reservoir	Weld	F	2.6 ft	-	63

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 →North Carolina version →All Colorado lakes →

Source: EPA National Aquatic Resource Surveys, 2026.