Fenner Lake
Fenner Lake in Marquette County, Wisconsin has a water quality grade of B (Good). Water clarity: 12 ft visibility. Phosphorus: 16.8 µg/L. Maximum depth: 18 ft. Surface area: 41 acres.
Wisconsin DNR lists Panfish as common on Fenner Lake. DNR survey details →
- Clarity
- 12 ft
- Max depth
- 18 ft
- Area
- 41 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
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Fenner Lake is a 41-acre mesotrophic lake in Marquette County, Wisconsin with a maximum depth of 18 feet. Water quality is graded B based on 1 sampling years through 2024. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 10 other monitored lakes in Marquette County, Fenner Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-07-24. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLow algae
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 12 ft. Phosphorus level: 16.8 µg/L. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12 ft | Not graded |
| Phosphorus | 16.8 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Fenner Lake
Compare lakeside cabins, hotels, and vacation rentals near Fenner Lake in Marquette 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 Fenner Lake
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Wisconsin DNR lists Panfish as common on Fenner Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Fenner Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 4 years of monitoring is improving. 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 2024).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 18 ft |
| Surface Area | 41 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Fenner LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Fenner Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.7 m/yr | 4 |
| Phosphorus | ↑ Improving | -0.75 µg/L/yr | 4 |
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Fenner Lake under Clean Water Act (NPDES) discharge permits.
- Slowey Farms LlcWestfield, Town Of · 2.8 mi away · NPDES WI0061913
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #7 of 11 lakes in Marquette County
Nearby Lakes in Marquette County
Frequently asked questions about Fenner Lake
Where is Fenner Lake?
- Fenner Lake is a lake in Marquette County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Fenner Lake?
- Fenner Lake in Marquette County, Wisconsin has a water quality grade of B (Good). Water clarity: 12 ft visibility. Phosphorus: 16.8 µg/L. Maximum depth: 18 ft. Surface area: 41 acres.
Is Fenner Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Fenner Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Fenner Lake?
- Fenner Lake has a maximum depth of 18 feet. The lake covers 41 acres.
What fish are in Fenner Lake?
- Fish species found in Fenner Lake include Panfish, Largemouth Bass, Northern Pike. Fenner Lake is located in Marquette County, Wisconsin.
What did the DNR fisheries survey find at Fenner Lake?
- Wisconsin DNR lists Panfish as common on Fenner Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Fenner Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 4 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Fenner Lake?
- Fenner Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Fenner Lake. Public access is listed as yes.
Explore Fenner Lake across LakeQuality
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Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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State Parks Near Fenner Lake
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
30 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX30 samples · 2021–2024
Analytical methods
- Phosphorus by Colorimetry
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory