Amacoy Lake
Rusk County, Wisconsin283 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Amacoy Lake. Here is what has been measured.
- Eutrophic
- Impaired · Cause unknown
- Curly-Leaf Pondweed
- 20 ft max depth
- Public access
Amacoy Lake in Rusk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.5 ft visibility. Phosphorus: 25.3 µg/L. Maximum depth: 20 ft. Surface area: 283 acres.
Wisconsin DNR rates Panfish as abundant on Amacoy Lake. DNR survey details →
Amacoy Lake is a 283-acre productive, nutrient-rich eutrophic lake in Rusk County, Wisconsin with a maximum depth of 20 feet. Overall water quality is improving over recent sampling years. The lake supports 7 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 3 other monitored lakes in Rusk County, Amacoy Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-26. Methodology: how these readings are compared.
What Amacoy Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing7 species recorded
Swimming conditions
Readings onlyRecreation use not supported
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. Amacoy Lake is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown. Check local advisories before you swim.
Whether Amacoy 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 Amacoy Lake
These are the measurements Wisconsin DNR publishes for Amacoy 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 4.5 ft. Phosphorus 25.3 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 25.3µg/L | Fair 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. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Amacoy Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Amacoy Lake typically sits around 67°F at the surface in September. Summer average is about 74°F. Usually warmest in Jul (about 76°F) and coldest in May (about 66°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (66°F) to its warmest (76°F).
Typical surface water temperature by month, from 20 field readings (2024–2026) via the EPA Water Quality Portal. See the full Amacoy Lake water temperature breakdown →
Wisconsin DNR rates Panfish as abundant on Amacoy Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Amacoy Lake’s water-quality measurements separately, 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 1986. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
20 ft
Surface area
283 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
42 sq mi
HydroLAKES / HydroSHEDS
Shoreline
3.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,060 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Amacoy LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
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Stays near Amacoy Lake
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Top-rated places to stay near Amacoy Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Amacoy 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 (2020–2026).
Water clarity
Stable7 years
Phosphorus
Improving-0.65 µg/L/yr6 years
Reservoir Info (USACE NID)
Amacoy Lake is a man-made reservoir impounded by the Amacoy (completed 1967), built primarily for flood risk reduction on the TR CHIPPEWA; earth-type dam, 20 ft tall and 300 ft long.
- Surface area
- 278 ac
- Normal storage
- 600 ac-ft
- Max storage
- 5,400 ac-ft
- Drainage area
- 5.3 sq mi
- Hazard class
- Low
- Owner
- Town Of Stubbs
All listed purposes: Flood Risk Reduction;Recreation.
Source: USACE National Inventory of Dams, NID ID WI00422 · Operator website
EPA Impairment Status
Amacoy Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
Source: EPA ATTAINS assessment unit WI10003999 · Official waterbody report
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Amacoy Lake under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Weyerhaeuser Village OfWeyerhaeuser · 4 mi away · NPDES WI0020761Recent violation
- Bruce Village OfBruce · 4.9 mi away · NPDES WI0060143Recent violation
- Nw Mink Ranch LlcBruce · 3.9 mi away · NPDES WI0062545
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 Rusk County
Frequently asked questions about Amacoy Lake
Where is Amacoy Lake?
- Amacoy Lake is a lake in Rusk County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Amacoy Lake?
- Amacoy Lake in Rusk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.5 ft visibility. Phosphorus: 25.3 µg/L. Maximum depth: 20 ft. Surface area: 283 acres.
Is Amacoy Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Amacoy Lake is listed impaired under Clean Water Act §303(d) (IR 5) for cause unknown. Check local advisories before you swim.
What is the water temperature of Amacoy Lake?
- Amacoy Lake typically sits around 67°F at the surface in September, from 20 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Amacoy Lake?
- Amacoy Lake has a maximum depth of 20 feet. The lake covers 283 acres.
What fish are in Amacoy Lake?
- Fish species found in Amacoy Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye, Catfish. Amacoy Lake is located in Rusk County, Wisconsin.
What did the DNR fisheries survey find at Amacoy Lake?
- Wisconsin DNR rates Panfish as abundant on Amacoy Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Amacoy Lake’s water-quality measurements separately, 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 Amacoy Lake?
- Amacoy Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Amacoy Lake. Public access is listed as yes.
Can I fish at Amacoy Lake?
- Amacoy 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 Amacoy Lake across LakeQuality
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Where this data comes from
41 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_WQX41 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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