What are mesotrophic lakes in Colorado?

27 mesotrophic lakes in Colorado. Moderate nutrients, good water quality.

What does mesotrophic mean?

Moderate nutrients, good water quality.

Mesotrophic Lakes in Colorado

Most well-managed working lakes register as mesotrophic — the band that balances productivity with clarity. 27 lakes in Colorado sit in the mesotrophic band. About 0% are deep (50+ ft); the rest are shallower basins where watershed management keeps nutrients from pushing the system into eutrophy.

Mesotrophic lakes tend to grade B or C on our A–F scale — the productive-but-clear band lines up with the middle of the letter grades.

#	Lake	County	Grade	Clarity	Depth	TSI
1	Pueblo Reservoir	Pueblo	A	6.5 ft	-	47
2	Lon Hagler Reservoir	Larimer	A	4.6 ft	-	49
3	Boyd Lake	Larimer	A	4.6 ft	-	50
4	Crystal Reservoir	Montrose	A	15.4 ft	-	40
5	Douglas Reservoir	Larimer	A	4.1 ft	-	45
6	Highline Lake	Mesa	A	3 ft	-	53
7	Elkhead Reservoir	Moffat	A	5.2 ft	-	48
8	Chambers Lake	Larimer	B	5.1 ft	-	46
9	Lake Granby Dam Bottom	Grand	B	-	-	41
10	Willow Creek Reservoir	Grand	C	3.9 ft	-	54
11	Grand Lake	Grand	C	8.7 ft	-	43
12	Skaguay Reservoir	Teller	C	12.5 ft	-	41
13	Sweitzer Reservoir	Delta	C	3.6 ft	-	54
14	Crawford Reservoir	Delta	C	5.6 ft	-	54
15	Ridgway Reservoir	Ouray	C	9.8 ft	-	47
16	The Loch Hypolimnion Lake	Larimer	C	-	-	41
17	The Loch Surface Lake	Larimer	C	-	-	43
18	Shadow Mountain Lake	Grand	D	7.9 ft	-	47
19	Blue Mesa Reservoir	Gunnison	D	11.5 ft	-	47
20	Dillon Reservoir	Summit	D	11.6 ft	-	47
21	Dowdy Lake	Larimer	D	8.2 ft	-	45
22	Elevenmile Reservoir	Park	D	13.1 ft	-	47
23	Haviland Lake	La Plata	D	13.8 ft	-	43
24	Turquoise Reservoir	Lake	D	16.1 ft	-	45
25	Steamboat Lake	Routt	D	6.6 ft	-	48
26	Windy Gap Reservoir	Grand	D	-	-	51
27	Sky Pond Hypolimnion	Larimer	D	-	-	44

All mesotrophic 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 →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 →Ontario version →Québec version →All Colorado lakes →

Source: EPA National Aquatic Resource Surveys, 2026.