Opal Lake is a cold, clear oligotrophic lake in Otsego County, Michigan. Water quality is graded A based on 1 sampling years through 2021. The lake supports 11 documented fish species including Bluntnose minnow, Common shiner, and Johnny darter. Compared to the 12 other monitored lakes in Otsego County, Opal Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Michigan DNR, last sampled 2021-09-23. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 18.5 ft down. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 18.5 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Opal Lake
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Fish Species
Click a species to see every graded lake where it is documented.
Fishing Opal Lake
Location & Depth Map
Free interactive depth-contour map of Opal Lake, reaching a maximum surveyed depth of 40 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
County Ranking
Ranked #4 of 13 lakes in Otsego County
Nearby Lakes in Otsego County
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Species activity outlook by water temperature and season
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Low nutrients, clear water, excellent for swimming
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Other Grade A Lakes in Michigan
Montmorency County · Clarity: 13 ft
Crawford County · Clarity: 19 ft
Crawford County · Clarity: 19 ft
Kalkaska County · Clarity: 18.5 ft
Kalkaska County · Excellent
Charlevoix County · Clarity: 17 ft
Oligotrophic Lakes in Michigan
More records, surveys & data sources
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Data Sources
Water quality data from the EPA Water Quality Portal
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Most recent sample: 2021-09-23
Monitoring stations: 1