Townsend Flowage Lake
Townsend Flowage Lake in Oconto County, Wisconsin has a water quality grade of B (Good). Phosphorus: 14.3 µg/L. Surface area: 476 acres.
- Max depth
- ~52 ft est.
- Area
- 476 acres
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- Yes
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Townsend Flowage Lake is a 476-acre mesotrophic lake in Oconto County, Wisconsin with an estimated average depth of about 52 feet. Water quality is graded B based on 1 sampling years through 2026. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 38 other monitored lakes in Oconto County, Townsend Flowage Lake ranks #31 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-15. 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)
No clarity data. Phosphorus level: 14.3 µg/L. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 14.3 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Townsend Flowage Lake
Compare lakeside cabins, hotels, and vacation rentals near Townsend Flowage Lake in Oconto 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.
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DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Townsend Flowage Lake covering fish populations, stocking, water quality, and management. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2016Townsend Lake comprehensive survey, 2016Comprehensive Survey · WI DNR · 2016 (PDF)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~52 ft est. |
| Average Depth | ~13 ft est. |
| Surface Area | 476 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wisconsin has not published bathymetry for Townsend Flowage Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Townsend FlowagePublic
- Townsend FlowagePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Townsend Flowage Lake
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.057 m/yr | 7 |
| Phosphorus | → Stable | -0.1 µg/L/yr | 7 |
Reservoir Info (USACE NID)
Townsend Flowage Lake is a man-made reservoir impounded by the Wheeler (completed 1880), built primarily for recreation on the MCCASLIN BROOK; gravity-type dam, 20 ft tall and 200 ft long.
- Surface area
- 476 ac
- Normal storage
- 3,900 ac-ft
- Max storage
- 5,300 ac-ft
- Drainage area
- 32 sq mi
- Hazard class
- High
- Owner
- Oconto County
Source: USACE National Inventory of Dams, NID ID WI00164 · Operator website
County Ranking
Ranked #31 of 39 lakes in Oconto County
Nearby Lakes in Oconto County
Frequently asked questions about Townsend Flowage Lake
Where is Townsend Flowage Lake?
- Townsend Flowage Lake is a lake in Oconto County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Townsend Flowage Lake?
- Townsend Flowage Lake in Oconto County, Wisconsin has a water quality grade of B (Good). Phosphorus: 14.3 µg/L. Surface area: 476 acres.
Is Townsend Flowage Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Townsend Flowage Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Townsend Flowage Lake?
- No published bathymetric survey covers Townsend Flowage Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 52 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 476 acres.
Are there boat ramps on Townsend Flowage Lake?
- Townsend Flowage Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Townsend Flowage, Townsend Flowage. Public access is listed as yes.
Explore Townsend Flowage Lake across LakeQuality
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Where this data comes from
23 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX23 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory