Seneca Lake
Seneca Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.3 ft visibility. Maximum depth: 10 ft. Surface area: 18 acres.
Wisconsin DNR lists Panfish as present on Seneca Lake. DNR survey details →
- Clarity
- 6.3 ft
- Max depth
- 10 ft
- Area
- 18 acres
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Why Seneca 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 Seneca Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). 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 WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Seneca Lake is a 18-acre lake in Vilas County, Wisconsin with a maximum depth of 10 feet. The lake supports 2 documented fish species including Panfish and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-08-30. Grade methodology: LakeQuality methodology.
Watch Seneca Lake water quality
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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 Seneca Lake
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 6.3 ft. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.3 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Seneca Lake
Compare lakeside cabins, hotels, and vacation rentals near Seneca Lake in Vilas 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.
Top-rated places to stay near Seneca Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as present on Seneca Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Seneca Lake — official chemistry is on file, not a letter. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2022).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 10 ft |
| Surface Area | 18 acres |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Seneca Lake
EPA Impairment Status
Seneca Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10026161 · Official waterbody report · Matched by proximity (2.89 km)
Graded lakes near Seneca Lake
Seneca Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Vilas County
Frequently asked questions about Seneca Lake
Where is Seneca Lake?
- Seneca Lake is a lake in Vilas County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Seneca Lake?
- Seneca Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.3 ft visibility. Maximum depth: 10 ft. Surface area: 18 acres.
Is Seneca Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Seneca 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 Seneca Lake?
- Seneca Lake has a maximum depth of 10 feet. The lake covers 18 acres.
What fish are in Seneca Lake?
- Fish species found in Seneca Lake include Panfish, Largemouth Bass. Seneca Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Seneca Lake?
- Wisconsin DNR lists Panfish as present on Seneca Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Seneca Lake — official chemistry is on file, not a letter. Catch rate is not a swim clearance and is not a weekly bite report.
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Where this data comes from
2 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX2 samples · 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.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Fish and recreation data from Wisconsin DNR Lakes