Corey Lake
Corey Lake in St. Joseph County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Surface area: 596.5 acres.
- Clarity
- 14.5 ft
- Area
- 597 acres
- Trend
- ↑ Improving
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Free interactive depth-contour map of Corey Lake, reaching a maximum surveyed depth of 70 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
Why Corey Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Corey Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by EGLE and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Corey Lake is a 597-acre lake in St. Joseph County, Michigan. Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including Bluegill, Bluntnose minnow, and Grass pickerel.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2022-09-17. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Corey Lake
These readings exist but are not enough for an A–F grade — see why.
Good clarity, visible to about 14.5 ft. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Corey Lake
Compare lakeside cabins, hotels, and vacation rentals near Corey Lake in St. Joseph County, Michigan — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Corey Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 597 acres |
No bathymetric survey has been published for Corey Lake, so its depth is not documented here.
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Corey Lake
Water Quality Trend: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.488 m/yr | 7 |
| Phosphorus | → Stable | +0.12 µg/L/yr | 5 |
| Chlorophyll-a | ↑ Improving | -0.05 µg/L/yr | 3 |
Graded lakes near Corey Lake
Corey Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Joseph County
Frequently asked questions about Corey Lake
Where is Corey Lake?
- Corey Lake is a lake in St. Joseph County, Michigan. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Corey Lake?
- Corey Lake in St. Joseph County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Surface area: 596.5 acres.
Is Corey Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Corey Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What fish are in Corey Lake?
- Fish species found in Corey Lake include Bluegill, Bluntnose minnow, Grass pickerel, Green sunfish, Hornyhead chub, Iowa darter, Lake chubsucker, Lake herring, Largemouth bass, Northern longear sunfish, Pumpkinseed, Western banded killifish, Yellow bullhead. Corey Lake is located in St. Joseph County, Michigan.
Explore Corey Lake across LakeQuality
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Where this data comes from
137 measurements from 1 monitoring station, 2016–2022. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- North American Lake Management Society
NALMS137 samples · 2016–2022
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.