Shannon Lake
Shannon Lake in Marinette County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 7.5 ft visibility. Phosphorus: 18.5 µg/L. Maximum depth: 37 ft. Surface area: 58 acres.
- Clarity
- 7.5 ft
- Max depth
- 37 ft
- Area
- 58 acres
- Trend
- ↑ Improving
Next lake in Marinette County
Why Shannon Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: 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 Shannon Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity and phosphorus, but not 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 WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Shannon Lake is a 58-acre lake in Marinette County, Wisconsin with a maximum depth of 37 feet. Overall water quality is improving over recent sampling years. The lake supports 1 documented fish species including Northern Pike.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-08-02. Grade methodology: LakeGrade 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 Shannon Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 7.5 ft. Phosphorus level: 18.5 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 7.5 ft | Not graded |
| Phosphorus | 18.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Shannon Lake
Compare lakeside cabins, hotels, and vacation rentals near Shannon Lake in Marinette County, Wisconsin — 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 |
|---|---|
| Maximum Depth | 37 ft |
| Surface Area | 58 acres |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Shannon Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2022).
Fish Species (DNR-rated)
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↑ Improving | -3.55 µg/L/yr | 2 |
Nearby Lakes in Marinette County
Frequently asked questions about Shannon Lake
What is the water quality grade for Shannon Lake?
- Shannon Lake in Marinette County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 7.5 ft visibility. Phosphorus: 18.5 µg/L. Maximum depth: 37 ft. Surface area: 58 acres.
Is Shannon Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Shannon Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Shannon Lake?
- Shannon Lake has a maximum depth of 37 feet. The lake covers 58 acres.
What fish are in Shannon Lake?
- Fish species found in Shannon Lake include Northern Pike. Shannon Lake is located in Marinette County, Wisconsin.
Explore Shannon Lake across LakeGrade
3.7 mi away
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Where this data comes from
4 measurements from 1 monitoring station, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX4 samples · 2020–2022
Analytical methods
- Phosphorus by Colorimetry
- Turbidity in Water
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.
Other records on this page
Fish and recreation data from Wisconsin DNR Lakes