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LakeQuality

Army Lake

B
Grade B — Good
Good · #12 of 19 lakes in the county · 8.2 ft clear · Mesotrophic · 80 acres
Limited DataMesotrophic

Army Lake in Walworth County, Wisconsin has a water quality grade of B (Good). Water clarity: 8.2 ft visibility. Phosphorus: 11.7 µg/L. Maximum depth: 17 ft. Surface area: 80 acres.

Wisconsin DNR rates Panfish as abundant on Army Lake. DNR survey details →

Clarity
8.2 ft
Max depth
17 ft
Area
80 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes

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Army Lake is a 80-acre mesotrophic lake in Walworth County, Wisconsin with a maximum depth of 17 feet. Water quality is graded B based on 1 sampling years through 2025. 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 18 other monitored lakes in Walworth County, Army Lake ranks #12 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-11. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Limited 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

Compare the safest swimming lakes near Milwaukee

Get alerts for Army Lake

Water Quality Grade: B (Good)

Moderate clarity, visible to about 8.2 ft. Phosphorus level: 11.7 µg/L. Trophic State Index: 43.

MetricValueGrade
Water Clarity (Secchi Depth)8.2 ftNot graded
Phosphorus11.7 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)43Mesotrophic

Moderate nutrients, good water quality

Where to stay near Army Lake

Compare lakeside cabins, hotels, and vacation rentals near Army Lake in Walworth 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 Army Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Wisconsin’s top lakes →

DNR fisheries survey

Wisconsin DNR rates Panfish as abundant on Army Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Army Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 6 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. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

Panfish(Abundant)Largemouth Bass(Common)Northern Pike(Present)

Lake Details

CharacteristicValue
Maximum Depth17 ft
Surface Area80 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Shoreline
1.4 mi
Elevation
810 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Army 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 Army 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.

Chinese Mystery SnailEurasian Water-MilfoilZebra Mussel

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+1.3 m/yr6
Phosphorus Improving-0.96 µg/L/yr5
Chlorophyll-a Improving-0.1 µg/L/yr3
See year-by-year chart →

EPA Impairment Status

Army Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Source: EPA ATTAINS assessment unit WI10000591 · Official waterbody report · Matched by proximity (1.99 km)

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Army Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

  • East Troy Wastewater Treatment Facility
    East Troy · 2.9 mi away · NPDES WI0020397
    Recent 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 #12 of 19 lakes in Walworth County

Nearby Lakes With Higher Grades

Army Lake holds Grade B. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.

Nearby Lakes in Walworth County

Frequently asked questions about Army Lake

Where is Army Lake?

Army Lake is a lake in Walworth County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Army Lake?

Army Lake in Walworth County, Wisconsin has a water quality grade of B (Good). Water clarity: 8.2 ft visibility. Phosphorus: 11.7 µg/L. Maximum depth: 17 ft. Surface area: 80 acres.

Is Army Lake safe to swim in?

Good for swimming, clear water with low algae levels. Army Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.

How deep is Army Lake?

Army Lake has a maximum depth of 17 feet. The lake covers 80 acres.

What fish are in Army Lake?

Fish species found in Army Lake include Panfish, Largemouth Bass, Northern Pike. Army Lake is located in Walworth County, Wisconsin.

What did the DNR fisheries survey find at Army Lake?

Wisconsin DNR rates Panfish as abundant on Army Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Army Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

Are there boat ramps on Army Lake?

Army Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Army Lake. Public access is listed as yes.

Where this data comes from

12 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX12 samples · 2021–2025

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)

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