What is the cleanest lake in Cache County, Utah?

Newton Reservoir in Cache County is the highest-rated lake in Cache County, Utah with an EPA water quality grade of A and 15.4 feet of water clarity.

How are these rankings calculated?

Lakes are graded A through F on nutrients and algae — total phosphorus, nitrogen, chlorophyll-a, and turbidity — against EPA National Lakes Assessment 2022 condition classes for that lake’s ecoregion. Water clarity (Secchi depth) is measured and shown; it is not the letter. Lakes without enough recent samples are UNRATED, not given an F. Source data comes from the EPA Water Quality Portal.

Cleanest Lakes in Cache County, Utah

Newton Reservoir in Cache County leads the rankings with a water quality grade of A and 15.4 ft of clarity. Below are the top 4 cleanest monitored lakes in Cache County, Utah, ranked by EPA water quality score.

Ranked List

#	Lake	County	Grade	Clarity	Phosphorus	Algae
1	Newton Reservoir	Cache	A	15.4 ft	26 µg/L	1.7 µg/L
2	Hyrum Reservoir	Cache	A	6.9 ft	17.9 µg/L	2.2 µg/L
3	Porcupine Reservoir	Cache	C	8.5 ft	13.3 µg/L	3.8 µg/L
4	Cutler Reservoir	Cache	D	1.2 ft	109 µg/L	17.4 µg/L

Ranked List

More Answers for Cache County, Utah