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LakeQuality

Crooked Lake

B
Grade B — Good
Good · #11 of 35 lakes in the county · 8 ft clear · Mesotrophic · 51 acres
Mesotrophic

Crooked Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 8 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 16 ft. Surface area: 51 acres.

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

Clarity
8 ft
Typical in August
77°F
Max depth
16 ft
Area
51 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes

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Crooked Lake is a 51-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 16 feet. Water quality is graded B 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 34 other monitored lakes in Waukesha County, Crooked Lake ranks #11 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-10. Grade methodology: LakeQuality 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.

Good for swimming, clear water with low algae levels

Compare the safest swimming lakes near Milwaukee

Get alerts for Crooked Lake

Water Quality Grade: B (Good)

Moderate clarity, visible to about 8 ft. Phosphorus level: 16.5 µg/L. Trophic State Index: 46.

MetricValueGrade
Water Clarity (Secchi Depth)8 ftNot graded
Phosphorus16.5 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)46Mesotrophic

Moderate nutrients, good water quality

Where to stay near Crooked Lake

Compare lakeside cabins, hotels, and vacation rentals near Crooked Lake in Waukesha 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 Crooked 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 →

Water Temperature

Crooked Lake typically sits around 77°F at the surface in August. Summer average is about 80°F. Usually warmest in Jun (about 84°F) and coldest in Mar (about 44°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
44°
Apr
May
Jun
84°
Jul
78°
Aug
77°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 16 field readings (20242025) via the EPA Water Quality Portal. See the full Crooked Lake water temperature breakdown →

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Crooked Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Crooked Lake B 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 1988. 2 stations on file (most recent sample 2025).

DNR Assessment
Excellent · Shallow Lowland lake
Trophic State Index 47 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

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

Lake Details

CharacteristicValue
Maximum Depth16 ft
Surface Area51 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Shoreline
1.5 mi
Elevation
876 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lower Genesee 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 Crooked 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.

Eurasian Water-MilfoilZebra Mussel

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.411 m/yr7
Phosphorus Improving-0.93 µg/L/yr7
See year-by-year chart →

County Ranking

Ranked #11 of 35 lakes in Waukesha County

Nearby Lakes in Waukesha County

Frequently asked questions about Crooked Lake

Where is Crooked Lake?

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

What is the water quality grade for Crooked Lake?

Crooked Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 8 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 16 ft. Surface area: 51 acres.

Is Crooked Lake safe to swim in?

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

What is the water temperature of Crooked Lake?

Crooked Lake typically sits around 77°F at the surface in August, from 16 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Crooked Lake?

Crooked Lake has a maximum depth of 16 feet. The lake covers 51 acres.

What fish are in Crooked Lake?

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

What did the DNR fisheries survey find at Crooked Lake?

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

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

State Parks Near Crooked Lake

Mesotrophic Lakes in Wisconsin

Where this data comes from

106 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 ResourcesWIDNR_WQX106 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

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