Dunes Lake
Dunes Lake in Door County, Wisconsin has a water quality grade of B (Good). Water clarity: 4 ft visibility. Phosphorus: 21.2 µg/L. Surface area: 48 acres.
- Clarity
- 4 ft
- Area
- 48 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
Next lake in Door County
Dunes Lake is a 48-acre productive, nutrient-rich eutrophic lake in Door County, Wisconsin. Water quality is graded B based on 1 sampling years through 2022. Overall water quality is improving over recent sampling years. Compared to the 4 other monitored lakes in Door County, Dunes Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-09-13. Grade methodology: LakeGrade methodology.
Watch Dunes Lake water quality
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Swimming Safety
Grade onlyLimited data
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)
Murky, only visible to about 4 ft. Phosphorus level: 21.2 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4 ft | Not graded |
| Phosphorus | 21.2 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Dunes Lake
Compare lakeside cabins, hotels, and vacation rentals near Dunes Lake in Door 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 Dunes Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 48 acres |
The available depth estimate for Dunes Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fishing Dunes Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 2 stations on file (most recent sample 2022).
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.5 m/yr | 2 |
| Phosphorus | ↑ Improving | -21.9 µg/L/yr | 2 |
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Dunes Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Sevastopol Sd No. 1 WwtfSturgeon Bay · 1.2 mi away · NPDES WI0026654Recent 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.
County Ranking
Ranked #4 of 5 lakes in Door County
Nearby Lakes in Door County
Frequently asked questions about Dunes Lake
What is the water quality grade for Dunes Lake?
- Dunes Lake in Door County, Wisconsin has a water quality grade of B (Good). Water clarity: 4 ft visibility. Phosphorus: 21.2 µg/L. Surface area: 48 acres.
Is Dunes Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Dunes Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Dunes Lake?
- The available depth estimate for Dunes Lake is shallower than its measured water clarity, which cannot be right, so no depth is shown. The lake covers 48 acres.
Explore Dunes Lake across LakeGrade
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Door County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Door County area
Where to stay at Wisconsin's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
State Parks Near Dunes Lake
Other Grade B Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Where this data comes from
12 measurements from 1 monitoring station, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX12 samples · 2021–2022
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes