Petenwell Flowage Lake
Juneau County, Wisconsin23,173 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Petenwell Flowage Lake. Here is what has been measured.
- Eutrophic
- Impaired · Dioxins
- Zebra Mussel
- 44 ft max depth
- Public access
Petenwell Flowage Lake in Juneau County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 81.7 µg/L. Maximum depth: 44 ft. Surface area: 23173 acres.
Wisconsin DNR lists Panfish as common on Petenwell Flowage Lake. DNR survey details →
Petenwell Flowage Lake is a 23,173-acre productive, nutrient-rich eutrophic lake in Juneau County, Wisconsin with a maximum depth of 44 feet. Overall water quality is declining over recent sampling years. The lake supports 8 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 14 public boat landings. Compared to the 1 other monitored lakes in Juneau County, Petenwell Flowage Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-20. Methodology: how these readings are compared.
What Petenwell Flowage Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch14 documented ramps
- Fishing8 species recorded
- Deep water44 ft surveyed max depth
- Big water23,173 acres
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Petenwell Flowage Lake is listed impaired under Clean Water Act §303(d) (IR 5) for dioxins, mercury, nutrients (phosphorus, nitrogen), pFAS, pCBs. Check local advisories before you swim.
Whether Petenwell Flowage 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 Petenwell Flowage Lake
These are the measurements Wisconsin DNR publishes for Petenwell Flowage Lake, 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 2.3 ft of visibility. Phosphorus 81.7 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 81.7µg/L | Poor GoodFairPoor |
| 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. | 66 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Petenwell Flowage Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Petenwell Flowage Lake typically sits around 74°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 79°F) and coldest in Apr (about 68°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (68°F) to its warmest (79°F).
Typical surface water temperature by month, from 8 field readings (2025–2026) via the EPA Water Quality Portal. See the full Petenwell Flowage Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Petenwell Flowage Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,584,893 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 lists Panfish as common on Petenwell Flowage Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Petenwell Flowage Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. 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. Monitored by volunteers since 2005. 60 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
Lake Details
Max depth
44 ft
Surface area
23,173 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
6,068 sq mi
HydroLAKES / HydroSHEDS
Shoreline
63.8 mi
HydroLAKES / HydroSHEDS
Elevation
915 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Wayside ParkPublic
- Petenwell Wilderness ParkPublic
- Petenwell County ParkPublic
- Monroe ParkPublic
- Chester CreekSemi-private
- Petenwell PowerhouseSemi-private
Showing 6 of 14 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 Petenwell Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Petenwell Flowage Lake in Juneau 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Petenwell Flowage Lake are listed below.
Top-rated places to stay near Petenwell Flowage Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Petenwell Flowage Lake
- → Petenwell Flowage Lake fishing: DNR survey catch rates, species & stocking
- → Petenwell Flowage Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Petenwell Flowage Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Petenwell Flowage Lake? (mercury & PFAS guide)
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: Worsening
Based on 6 years of monitoring (2020–2026).
Water clarity
Stable6 years
Phosphorus
Worsening+4.76 µg/L/yr5 years
EPA Impairment Status
Petenwell Flowage Lake 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, Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit WI10008638 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Petenwell Flowage Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Central Sands Dairy LlcArmenia, Town Of · 4.4 mi away · NPDES WI0063533Recent 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 Juneau County
Frequently asked questions about Petenwell Flowage Lake
Where is Petenwell Flowage Lake?
- Petenwell Flowage Lake is a lake in Juneau County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Petenwell Flowage Lake?
- Petenwell Flowage Lake in Juneau County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 81.7 µg/L. Maximum depth: 44 ft. Surface area: 23173 acres.
Is Petenwell Flowage Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Petenwell Flowage Lake is listed impaired under Clean Water Act §303(d) (IR 5) for dioxins, mercury, nutrients (phosphorus, nitrogen), pFAS, pCBs. Check local advisories before you swim.
What is the water temperature of Petenwell Flowage Lake?
- Petenwell Flowage Lake typically sits around 74°F at the surface in August, from 8 EPA Water Quality Portal field readings (2025–2026). That is a typical value for the month, not a live reading.
How deep is Petenwell Flowage Lake?
- Petenwell Flowage Lake has a maximum depth of 44 feet. The lake covers 23173 acres.
What fish are in Petenwell Flowage Lake?
- Fish species found in Petenwell Flowage Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye, Sturgeon, Catfish. Petenwell Flowage Lake is located in Juneau County, Wisconsin.
What did the DNR fisheries survey find at Petenwell Flowage Lake?
- Wisconsin DNR lists Panfish as common on Petenwell Flowage Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Petenwell Flowage Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Does Petenwell Flowage Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Petenwell Flowage Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,584,893 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Petenwell Flowage Lake?
- Petenwell Flowage Lake has 14 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Wayside Park, Petenwell Wilderness Park, Petenwell County Park, Monroe Park, among others. Public access is listed as yes.
Can I fish at Petenwell Flowage Lake?
- Petenwell Flowage Lake has 14 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 Petenwell Flowage Lake across LakeQuality
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Where this data comes from
67 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_WQX67 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
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)
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