What is the cleanest lake in Marion County, Indiana?

Eagle Creek Reservoir in Marion County is the highest-rated lake in Marion County, Indiana with an EPA water quality grade of NR.

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 Marion County, Indiana

Eagle Creek Reservoir in Marion County leads the rankings with a water quality grade of NR. Below are the top 3 cleanest monitored lakes in Marion County, Indiana, ranked by EPA water quality score.

Ranked List

#	Lake	County	Grade	Clarity	Phosphorus	Algae
1	Eagle Creek Reservoir	Marion	NR	-	-	-
2	Indian Lake	Marion	NR	-	-	-
3	Geist Reservoir	Marion	NR	-	-	-

Ranked List

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