Flynn Lake
Bayfield County, Wisconsin30 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Flynn Lake. Here is what has been measured.
- 9 ft max depth
- Limited data
Flynn Lake in Bayfield County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Maximum depth: 9 ft. Surface area: 30 acres.
Wisconsin DNR rates Largemouth Bass as abundant on Flynn Lake. DNR survey details →
Flynn Lake is a 30-acre lake in Bayfield County, Wisconsin with a maximum depth of 9 feet. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-06-01. Methodology: how these readings are compared.
What Flynn Lake is good for
From access and monitoring records, not editorial picks.
- Fishing6 species recorded
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Flynn Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Flynn Lake
These are the measurements Wisconsin DNR publishes for Flynn Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9 ft. TSI 45.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 45 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Flynn Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR rates Largemouth Bass as abundant on Flynn Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Flynn Lake’s water-quality measurements separately, and the water-quality trend over 7 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. 2 stations on file (most recent sample 2023).
Fish Species (DNR-rated)
Lake Details
Max depth
9 ft
Surface area
30 acres
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Fish Species
Click a species to see every lake where it is documented.
Fishing Flynn 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 7 years of monitoring (2020–2026).
Water clarity
Improving5 years
Phosphorus
Stable0 µg/L/yr7 years
Reservoir Info (USACE NID)
Flynn Lake is a man-made reservoir impounded by the Murrays (completed 1941), built primarily for recreation on the EAST FORK WHITE; gravity-type dam, 13 ft tall and 34 ft long.
- Surface area
- 650 ac
- Normal storage
- 19,960 ac-ft
- Max storage
- 22,000 ac-ft
- Drainage area
- 13 sq mi
- Hazard class
- Low
- Owner
- Bayfield County
Source: USACE National Inventory of Dams, NID ID WI00103 · Operator website · Matched by proximity (0.25 km)
Nearby Lakes in Bayfield County
Frequently asked questions about Flynn Lake
Where is Flynn Lake?
- Flynn Lake is a lake in Bayfield County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Flynn Lake?
- Flynn Lake in Bayfield County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Maximum depth: 9 ft. Surface area: 30 acres.
Is Flynn Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Flynn Lake?
- Flynn Lake has a maximum depth of 9 feet. The lake covers 30 acres.
What fish are in Flynn Lake?
- Fish species found in Flynn Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Flynn Lake is located in Bayfield County, Wisconsin.
What did the DNR fisheries survey find at Flynn Lake?
- Wisconsin DNR rates Largemouth Bass as abundant on Flynn Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Flynn Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
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Where this data comes from
12 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX12 samples · 2020–2023
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Fish and recreation data from Wisconsin DNR Lakes