Griswold Lake
Griswold Lake in McHenry County, Illinois is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 153 acres.
- Area
- 153 acres
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Why Griswold 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 Griswold Lake, no water-quality sampling on record for this lake.
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 Illinois EPA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Griswold Lake is a 153-acre lake in McHenry County, Illinois.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled recent years. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedElevated nutrients
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Griswold Lake
These readings exist but are not enough for an A–F grade — see why.
No clarity data. Trophic State Index: undefined.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) |
Where to stay near Griswold Lake
Compare lakeside cabins, hotels, and vacation rentals near Griswold Lake in McHenry County, Illinois — 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.
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 153 acres |
No bathymetric survey has been published for Griswold Lake, so its depth is not documented here.
Fishing Griswold Lake
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Frequently asked questions about Griswold Lake
Where is Griswold Lake?
- Griswold Lake is a lake in McHenry County, Illinois. LakeQuality has not rated this lake (UNRATED) — no water-quality sampling on record for this lake.
What is the water quality grade for Griswold Lake?
- Griswold Lake in McHenry County, Illinois is not rated for water quality — its monitoring record does not meet the evidence bar. Surface area: 153 acres.
Is Griswold Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Griswold Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
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Where this data comes from
Measurements for Griswold Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.