Big Butternut Lake
Big Butternut Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 4.5 ft visibility. Phosphorus: 62.1 µg/L. Maximum depth: 19 ft. Surface area: 384 acres.
Wisconsin DNR lists Panfish as common on Big Butternut Lake. DNR survey details →
- Clarity
- 4.5 ft
- Max depth
- 19 ft
- Area
- 384 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Big Butternut Lake →
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Big Butternut Lake is a 384-acre productive, nutrient-rich eutrophic lake in Polk County, Wisconsin with a maximum depth of 19 feet. Water quality is graded D based on 1 sampling years through 2025. Water clarity is improving over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 54 other monitored lakes in Polk County, Big Butternut Lake ranks #44 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-01. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyElevated nutrients
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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4.5 ft. Phosphorus level: 62.1 µg/L. Trophic State Index: 60.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.5 ft | Not graded |
| Phosphorus | 62.1 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 60 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Big Butternut Lake
Compare lakeside cabins, hotels, and vacation rentals near Big Butternut Lake in Polk 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 grade measures nutrients and algae, not lodging — cabins and rentals around Big Butternut Lake are listed below.
Top-rated places to stay near Big Butternut Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as common on Big Butternut Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Big Butternut Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 5 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. Monitored by volunteers since 1995. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 19 ft |
| Surface Area | 384 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Big Butternut LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Big Butternut 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: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +1.488 m/yr | 4 |
| Phosphorus | ↓ Declining | +7.52 µg/L/yr | 5 |
EPA Impairment Status
Big Butternut Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10005133 · Official waterbody report
County Ranking
Ranked #44 of 55 lakes in Polk County
Nearby Lakes With Higher Grades
Big Butternut Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Polk County
Frequently asked questions about Big Butternut Lake
Where is Big Butternut Lake?
- Big Butternut Lake is a lake in Polk County, Wisconsin. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Big Butternut Lake?
- Big Butternut Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 4.5 ft visibility. Phosphorus: 62.1 µg/L. Maximum depth: 19 ft. Surface area: 384 acres.
Is Big Butternut Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Big Butternut Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
How deep is Big Butternut Lake?
- Big Butternut Lake has a maximum depth of 19 feet. The lake covers 384 acres.
What fish are in Big Butternut Lake?
- Fish species found in Big Butternut Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Big Butternut Lake is located in Polk County, Wisconsin.
What did the DNR fisheries survey find at Big Butternut Lake?
- Wisconsin DNR lists Panfish as common on Big Butternut Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Big Butternut Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 5 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Big Butternut Lake?
- Big Butternut Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Big Butternut Lake. Public access is listed as yes.
Explore Big Butternut Lake across LakeQuality
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
36 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX36 samples · 2020–2025
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
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
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