Clam Lake
Clam Lake in Burnett County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 77.5 µg/L. Chlorophyll-a (algae): 13 µg/L. Maximum depth: 11 ft. Surface area: 1338 acres.
- Clarity
- 3 ft
- Typical in August
- 72°F
- Max depth
- 11 ft
- Area
- 1,338 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Clam Lake →
Next lake in Burnett County
Clam Lake is a 1,338-acre productive, nutrient-rich eutrophic lake in Burnett County, Wisconsin with a maximum depth of 11 feet. Water quality is graded D based on 3 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 7 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available. Compared to the 29 other monitored lakes in Burnett County, Clam Lake ranks #28 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-27. Grade methodology: LakeGrade 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)
Very murky, less than 3 ft of visibility. Phosphorus level: 77.5 µg/L. Chlorophyll-a: 13 µg/L. Trophic State Index: 61.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | Not graded |
| Phosphorus | 77.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 13 µg/L | Fair |
| Trophic State Index (TSI) | 61 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Clam Lake
Compare lakeside cabins, hotels, and vacation rentals near Clam Lake in Burnett 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 Clam Lake are listed below.
Top-rated places to stay near Clam Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Water Temperature
Clam Lake typically sits around 72°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 81°F) and coldest in Oct (about 50°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 40 field readings (2024–2025) via the EPA Water Quality Portal. See the full Clam Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 11 ft |
| Surface Area | 1,338 acres |
| Public Access | Yes |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Clam 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.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2009. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
DNR Reports & Resources
Wisconsin DNR Fisheries scientists publish multi-year survey reports for Clam Lake covering fish populations, stocking, water quality, and management. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- 2024Clam Lake comprehensive survey, 2024Comprehensive Survey · WI DNR · 2024 (PDF)
- 2018Upper Clam River trout assessment 2018Trout Survey · WI DNR · 2018 (PDF)
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.207 m/yr | 6 |
| Phosphorus | ↓ Declining | +9.2 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +3.65 µg/L/yr | 6 |
Reservoir Info (USACE NID)
Clam Lake is a man-made reservoir impounded by the Clam Lake (completed 1936), built primarily for recreation on the CLAM; gravity-type dam, 10 ft tall and 110 ft long.
- Surface area
- 1,207 ac
- Normal storage
- 3,600 ac-ft
- Max storage
- 9,600 ac-ft
- Drainage area
- 325 sq mi
- Hazard class
- Low
- Owner
- Burnett County
Source: USACE National Inventory of Dams, NID ID WI00619 · Operator website
EPA Impairment Status
Clam 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 WI10006735 · Official waterbody report
County Ranking
Ranked #28 of 30 lakes in Burnett County
Nearby Lakes With Higher Grades
Clam 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 Burnett County
Frequently asked questions about Clam Lake
What is the water quality grade for Clam Lake?
- Clam Lake in Burnett County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 3 ft visibility. Phosphorus: 77.5 µg/L. Chlorophyll-a (algae): 13 µg/L. Maximum depth: 11 ft. Surface area: 1338 acres.
Is Clam 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. Clam Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 13 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Clam Lake?
- Clam Lake typically sits around 72°F at the surface in August, from 40 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Clam Lake?
- Clam Lake has a maximum depth of 11 feet. The lake covers 1338 acres.
What fish are in Clam Lake?
- Fish species found in Clam Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye, Sturgeon, Catfish. Clam Lake is located in Burnett County, Wisconsin.
Explore Clam Lake across LakeGrade
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Where this data comes from
183 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- St. Croix Chippewa Indians of Wisconsin
STCROIX_WQX183 samples · 2020–2025
Analytical methods
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
- 10200 H ~ Chlorophyll a-b-c Determination
- Calculation
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