Lake Poygan
Winnebago County, Wisconsin14,024 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Lake Poygan. Here is what has been measured.
- Impaired · Cause unknown
- 5 aquatic invasives
- 11 ft max depth
- Public access
- Limited data
Lake Poygan in Winnebago County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 2.5 ft visibility. Maximum depth: 11 ft. Surface area: 14024 acres.
Wisconsin DNR rates Panfish, Sturgeon, and Catfish as abundant on Lake Poygan. DNR survey details →
Lake Poygan is a 14,024-acre lake in Winnebago County, Wisconsin with a maximum depth of 11 feet. The lake supports 8 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 8 public boat landings.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-27. Methodology: how these readings are compared.
At about 14,000 acres, Lake Poygan is large enough that where you stay decides which shore you see most of. It has 8 public boat landings, so a lakefront rental is not the only way to get a boat on the water. If you are planning to stay, you can search lake houses and cabins around Lake Poygan on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Lake Poygan is good for
From access and monitoring records, not editorial picks.
- Boat launch8 documented ramps
- Fishing8 species recorded
- Big water14,024 acres
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Lake Poygan is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
Whether Lake Poygan 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 Lake Poygan
These are the measurements Wisconsin DNR publishes for Lake Poygan, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.5 ft of visibility. TSI 64.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.5ft | 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. | 64 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Poygan
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lake Poygan typically sits around 52°F at the surface in October. Summer average is about 75°F. Usually warmest in Jul (about 76°F) and coldest in Oct (about 52°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (52°F) to its warmest (76°F).
Typical surface water temperature by month, from 46 field readings (2024–2026) via the EPA Water Quality Portal. See the full Lake Poygan water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Lake Poygan — clouds, ice, or an off-season gap in coverage. The most recent reading was high (539,511 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR rates Panfish, Sturgeon, and Catfish as abundant on Lake Poygan.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Poygan’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. 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. 17 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
11 ft
Surface area
14,024 acres
Public access
Yes
Listed by Wisconsin DNR
Recreation & Access
- Wolf River Crossing ParkPublic
- 35th LanePublic
- Badger DrivePublic
- Boom BayPublic
- Poygan Shores LanePublic
- Lake PoyganPublic
Showing 6 of 8 documented landings from the USGS National Boat Ramps inventory.
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lake Poygan
Compare lakeside cabins, hotels, and vacation rentals near Lake Poygan in Winnebago 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 Lake Poygan
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Lake Poygan → · more Wisconsin lake trips
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lake Poygan
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: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
EPA Impairment Status
Lake Poygan is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit WI10006159 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Lake Poygan under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Poygan Poy Sippi Sd 1 WwtfWinneconne · 1.6 mi away · NPDES WI0035513Recent violation
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.
Nearby Lakes in Winnebago County
Frequently asked questions about Lake Poygan
Where is Lake Poygan?
- Lake Poygan is a lake in Winnebago County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Lake Poygan?
- Lake Poygan in Winnebago County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 2.5 ft visibility. Maximum depth: 11 ft. Surface area: 14024 acres.
Is Lake Poygan safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Poygan is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown, nutrients (phosphorus, nitrogen), turbidity. Check local advisories before you swim.
What is the water temperature of Lake Poygan?
- Lake Poygan typically sits around 52°F at the surface in October, from 46 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Lake Poygan?
- Lake Poygan has a maximum depth of 11 feet. The lake covers 14024 acres.
What fish are in Lake Poygan?
- Fish species found in Lake Poygan include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye, Sturgeon, Catfish. Lake Poygan is located in Winnebago County, Wisconsin.
What did the DNR fisheries survey find at Lake Poygan?
- Wisconsin DNR rates Panfish, Sturgeon, and Catfish as abundant on Lake Poygan. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Poygan’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Does Lake Poygan have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Lake Poygan (clouds, ice, or an off-season gap). The most recent reading was high (539,511 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Lake Poygan?
- Lake Poygan has 8 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Wolf River Crossing Park, 35th Lane, Badger Drive, Boom Bay, among others. Public access is listed as yes.
Can I fish at Lake Poygan?
- Lake Poygan has 8 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Lake Poygan across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Winnebago County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Lakes in the Wolf River Watershed, ranked by water quality
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Wisconsin's cleanest lakes, ranked on agency measurements
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Where this data comes from
54 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX54 samples · 2020–2026
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory