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Lake Beulah

A
Grade A — Excellent
Excellent · #2 of 19 lakes in the county · 10 ft clear · Mesotrophic · 812 acres
Mesotrophic

Lake Beulah in Walworth County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 10 ft visibility. Phosphorus: 13.4 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 58 ft. Surface area: 812 acres.

Wisconsin DNR lists Panfish as common on Lake Beulah. DNR survey details →

Clarity
10 ft
Typical in August
77°F
Max depth
58 ft
Area
812 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes

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Lake Beulah is a 812-acre mesotrophic lake in Walworth County, Wisconsin with a maximum depth of 58 feet. Water quality is graded A based on 2 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 18 other monitored lakes in Walworth County, Lake Beulah ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-05-08. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Low algae

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.

Excellent for swimming, crystal clear water with minimal algae

Compare the safest swimming lakes near Milwaukee

Get alerts for Lake Beulah

Water Quality Grade: A (Excellent)

Good clarity, visible to about 10 ft. Phosphorus level: 13.4 µg/L. Chlorophyll-a: 2.5 µg/L. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)10 ftNot graded
Phosphorus13.4 µg/LGood
Chlorophyll-a (Algae)2.5 µg/LGood
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Where to stay near Lake Beulah

Compare lakeside cabins, hotels, and vacation rentals near Lake Beulah 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 Lake Beulah

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 →

Water Temperature

Lake Beulah typically sits around 77°F at the surface in August. Summer average is about 80°F. Usually warmest in Jun (about 82°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
58°
Jun
82°
Jul
81°
Aug
77°
Sep
72°
Oct
Nov
Dec

Typical surface water temperature by month, from 14 field readings (20242026) via the EPA Water Quality Portal.

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Lake Beulah — clouds, ice, or an off-season gap in coverage. The most recent reading was high (222,844 cells/mL) on March 28, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Lake Beulah.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Lake Beulah A 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. Monitored by volunteers since 1991. 7 stations on file (most recent sample 2026).

DNR Assessment
Reported
Trophic State Index 44 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

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

Lake Details

CharacteristicValue
Maximum Depth58 ft
Surface Area812 acres
Public AccessYes

Recreation & Access

1
Boat Landings
Yes
Public Access

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Lake Beulah

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Curly-Leaf PondweedEurasian Water-MilfoilHybrid Eurasian / Northern Water-MilfoilPurple LoosestrifeZebra Mussel

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

MetricTrendChange/YearYears
Water Clarity Improving+0.726 m/yr6
Phosphorus Improving-0.61 µg/L/yr6
Chlorophyll-a Declining+0.1 µg/L/yr3
See year-by-year chart →

Reservoir Info (USACE NID)

Lake Beulah is a man-made reservoir impounded by the Lake Beulah (completed 1840), built primarily for recreation on the Lake Beulah Outlet; gravity-type dam, 14 ft tall and 300 ft long.

Surface area
834 ac
Normal storage
5,000 ac-ft
Max storage
7,000 ac-ft
Drainage area
10 sq mi
Hazard class
High
Owner
Lake Beulah Management District;Walworth County

Source: USACE National Inventory of Dams, NID ID WI00699 · Operator website

EPA Impairment Status

Lake Beulah 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

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Lake Beulah under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger.

  • Plymouth Tube Co East Troy & Trent Plants
    East Troy · 1.7 mi away · NPDES WI0038938
    Major

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 #2 of 19 lakes in Walworth County

Nearby Lakes in Walworth County

Frequently asked questions about Lake Beulah

Where is Lake Beulah?

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

What is the water quality grade for Lake Beulah?

Lake Beulah in Walworth County, Wisconsin has a water quality grade of A (Excellent). Water clarity: 10 ft visibility. Phosphorus: 13.4 µg/L. Chlorophyll-a (algae): 2.5 µg/L. Maximum depth: 58 ft. Surface area: 812 acres.

Is Lake Beulah safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Lake Beulah has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2.5 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Lake Beulah?

Lake Beulah typically sits around 77°F at the surface in August, from 14 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.

How deep is Lake Beulah?

Lake Beulah has a maximum depth of 58 feet. The lake covers 812 acres.

What fish are in Lake Beulah?

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

What did the DNR fisheries survey find at Lake Beulah?

Wisconsin DNR lists Panfish as common on Lake Beulah. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Lake Beulah A 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.

Does Lake Beulah have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Lake Beulah (clouds, ice, or an off-season gap). The most recent reading was high (222,844 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.

Are there boat ramps on Lake Beulah?

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

Where this data comes from

147 measurements from 6 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX95 samples · 2020–2026
  • USGS Wisconsin Water Science CenterUSGS-WI52 samples · 2020–2022

Analytical methods

  • Phosphorus by Colorimetry
  • Turbidity in Water
Monitoring station identifiers (6)

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