Lake Thirty
Barron County, Wisconsin75 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Lake Thirty. Here is what has been measured.
- Impaired · Nutrients (phosphorus, nitrogen)
- 27 ft max depth
- Public access
- Limited data
Lake Thirty in Barron County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.8 ft visibility. Phosphorus: 19.4 µg/L. Maximum depth: 27 ft. Surface area: 75 acres.
Wisconsin DNR lists Panfish as common on Lake Thirty. DNR survey details →
Lake Thirty is a 75-acre lake in Barron County, Wisconsin with a maximum depth of 27 feet. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-07-28. Methodology: how these readings are compared.
What Lake Thirty is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing3 species recorded
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Lake Thirty is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Lake Thirty 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 Thirty
These are the measurements Wisconsin DNR publishes for Lake Thirty, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 4.8 ft. Phosphorus 19.4 µg/L. TSI 51.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 19.4µg/L | Measured, not scored 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. | 51 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Thirty
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as common on Lake Thirty.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Thirty’s water-quality measurements separately, and the water-quality trend over 7 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. 1 station on file (most recent sample 2022).
Fish Species (DNR-rated)
Lake Details
Max depth
27 ft
Surface area
75 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.9 mi
HydroLAKES / HydroSHEDS
Elevation
1,253 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Lake ThirtyPublic
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 Thirty
Compare lakeside cabins, hotels, and vacation rentals near Lake Thirty in Barron 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 Thirty
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lake Thirty
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 7 years of monitoring (2020–2026).
Water clarity
Stable7 years
Phosphorus
Stable-0.22 µg/L/yr6 years
EPA Impairment Status
Lake Thirty is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Designated uses not supporting: Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit WI10004486 · Official waterbody report
Nearby Lakes in Barron County
Frequently asked questions about Lake Thirty
Where is Lake Thirty?
- Lake Thirty is a lake in Barron 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 Thirty?
- Lake Thirty in Barron County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.8 ft visibility. Phosphorus: 19.4 µg/L. Maximum depth: 27 ft. Surface area: 75 acres.
Is Lake Thirty safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Thirty is listed impaired under Clean Water Act §303(d) (IR 5R) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Lake Thirty?
- Lake Thirty has a maximum depth of 27 feet. The lake covers 75 acres.
What fish are in Lake Thirty?
- Fish species found in Lake Thirty include Panfish, Largemouth Bass, Northern Pike. Lake Thirty is located in Barron County, Wisconsin.
What did the DNR fisheries survey find at Lake Thirty?
- Wisconsin DNR lists Panfish as common on Lake Thirty. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lake Thirty’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Lake Thirty?
- Lake Thirty has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Thirty. Public access is listed as yes.
Can I fish at Lake Thirty?
- Lake Thirty has 1 documented boat landing 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.
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Where this data comes from
3 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX3 samples · 2022
Analytical methods
- Phosphorus by Colorimetry
- Turbidity in Water
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
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