Gass Lake
Gass Lake in Manitowoc County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 6 ft visibility. Phosphorus: 61 µg/L. Maximum depth: 24 ft. Surface area: 6 acres.
Wisconsin DNR lists Panfish as common on Gass Lake. DNR survey details →
- Clarity
- 6 ft
- Max depth
- 24 ft
- Area
- 6 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Gass Lake →
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Gass Lake is a 6-acre productive, nutrient-rich eutrophic lake in Manitowoc County, Wisconsin with a maximum depth of 24 feet. Water quality is graded D based on 1 sampling years through 2026. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 15 other monitored lakes in Manitowoc County, Gass Lake ranks #14 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-20. 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 6 ft. Phosphorus level: 61 µg/L. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6 ft | Not graded |
| Phosphorus | 61 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Gass Lake
Compare lakeside cabins, hotels, and vacation rentals near Gass 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 grade measures nutrients and algae, not lodging — cabins and rentals around Gass Lake are listed below.
Top-rated places to stay near Gass 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 Gass Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Gass Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. 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 2012. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 24 ft |
| Surface Area | 6 acres |
| Public Access | Yes |
Recreation & Access
- Gass 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 Gass 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: ↑ Improving
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.036 m/yr | 6 |
| Phosphorus | ↑ Improving | -6.71 µg/L/yr | 7 |
EPA Impairment Status
Gass Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit WI10000133 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Gass Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Manitowoc Wastewater Treatment FacilityManitowoc · 4.6 mi away · NPDES WI0024601MajorRecent 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 #14 of 16 lakes in Manitowoc County
Nearby Lakes With Higher Grades
Gass Lake holds Grade D. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Manitowoc County
Frequently asked questions about Gass Lake
Where is Gass Lake?
- Gass Lake is a lake in Manitowoc County, Wisconsin. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Gass Lake?
- Gass Lake in Manitowoc County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 6 ft visibility. Phosphorus: 61 µg/L. Maximum depth: 24 ft. Surface area: 6 acres.
Is Gass 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. Gass Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
How deep is Gass Lake?
- Gass Lake has a maximum depth of 24 feet. The lake covers 6 acres.
What fish are in Gass Lake?
- Fish species found in Gass Lake include Panfish, Largemouth Bass, Northern Pike. Gass Lake is located in Manitowoc County, Wisconsin.
What did the DNR fisheries survey find at Gass Lake?
- Wisconsin DNR lists Panfish as common on Gass Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Gass Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Gass Lake?
- Gass Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Gass Lake. Public access is listed as yes.
Explore Gass Lake across LakeQuality
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Where this data comes from
50 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX50 samples · 2020–2026
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory