Carstens Lake
Manitowoc County, WisconsinView mapDirections
Wisconsin DNR publishes the water-quality measurements for Carstens Lake. Here is what has been measured.
- Eutrophic
- Public access
Carstens Lake in Manitowoc County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.2 ft visibility. Phosphorus: 89.7 µg/L.
Carstens Lake is a productive, nutrient-rich eutrophic lake in Manitowoc County, Wisconsin. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 15 other monitored lakes in Manitowoc County, Carstens Lake ranks #16 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-22. Methodology: how these readings are compared.
What Carstens Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyElevated nutrients
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Carstens Lake 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 Carstens Lake
These are the measurements Wisconsin DNR publishes for Carstens Lake, 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 5.2 ft. Phosphorus 89.7 µg/L. TSI 61.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 89.7µg/L | Poor GoodFairPoor |
| 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. | 61 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Carstens Lake
Answers come straight from the public measurements and survey records on this page.
Recreation & Access
- Carstens LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Carstens Lake
Compare lakeside cabins, hotels, and vacation rentals near Carstens Lake in Manitowoc 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Carstens Lake are listed below.
Top-rated places to stay near Carstens Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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Fishing Carstens Lake
Water Quality Trend: Improving
Based on 7 years of monitoring (2020–2026).
Phosphorus
Improving-12.89 µg/L/yr7 years
Regulated Pollution Sources Nearby
5 EPA-permitted facilities operate within about 5 miles of Carstens Lake under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Grotegut Dairy Farm IncNewton · 2.1 mi away · NPDES WI0056847Recent violation
- Maple Leaf Dairy IncCleveland · 5 mi away · NPDES WI0058602Recent violation
- A H Stock Mfg & Stocks Dnr CluNewton · 2.4 mi away · NPDES WI0030341
- Glacier Rock Enterprises, Inc.Newton · 2.5 mi away · NPDES WI0058581
- Newton Meats And SausageNewton · 2.8 mi away · NPDES WI0042650
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.
Nearby Lakes in Manitowoc County
Frequently asked questions about Carstens Lake
Where is Carstens Lake?
- Carstens Lake is a lake in Manitowoc County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Carstens Lake?
- Carstens Lake in Manitowoc County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 5.2 ft visibility. Phosphorus: 89.7 µg/L.
Is Carstens Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there boat ramps on Carstens Lake?
- Carstens Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Carstens Lake. Public access is listed as yes.
Can I fish at Carstens Lake?
- Carstens Lake 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.
Explore Carstens Lake across LakeQuality
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Where this data comes from
28 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_WQX28 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory