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LakeQuality

Pretty Lake

B
Grade B — Good
Good · #13 of 35 lakes in the county · 12.2 ft clear · Mesotrophic · 65 acres · from A
Mesotrophic

Pretty Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 12.2 ft visibility. Phosphorus: 12.2 µg/L. Maximum depth: 31 ft. Surface area: 65 acres.

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

Clarity
12.2 ft
Typical in August
79°F
Max depth
31 ft
Area
65 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes

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Pretty Lake is a 65-acre mesotrophic lake in Waukesha County, Wisconsin with a maximum depth of 31 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, Pretty Lake ranks #13 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-22. 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 Pretty Lake

Water Quality Grade: B (Good)

Good clarity, visible to about 12.2 ft. Phosphorus level: 12.2 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)12.2 ftNot graded
Phosphorus12.2 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Where to stay near Pretty Lake

Compare lakeside cabins, hotels, and vacation rentals near Pretty 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 Pretty 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

Pretty Lake typically sits around 79°F at the surface in August. Summer average is about 78°F. Usually warmest in Jul (about 80°F) and coldest in Apr (about 48°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
48°
May
65°
Jun
76°
Jul
80°
Aug
79°
Sep
74°
Oct
57°
Nov
Dec

Typical surface water temperature by month, from 29 field readings (20242025) via the EPA Water Quality Portal. See the full Pretty Lake water temperature breakdown →

DNR fisheries survey

Wisconsin DNR rates Panfish as abundant on Pretty Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Pretty 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 1989. 2 stations on file (most recent sample 2025).

DNR Assessment
Excellent · Deep Seepage lake
Trophic State Index 37 (oligotrophic) · 5-year average

Fish Species (DNR-rated)

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

Lake Details

CharacteristicValue
Maximum Depth31 ft
Surface Area65 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Shoreline
1.1 mi
Elevation
866 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Pretty 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 Pretty 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.

Banded Mystery SnailEurasian Water-Milfoil

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

MetricTrendChange/YearYears
Water Clarity Improving+0.368 m/yr6
Phosphorus Stable-0.14 µg/L/yr7
See year-by-year chart →

County Ranking

Ranked #13 of 35 lakes in Waukesha County

Nearby Lakes in Waukesha County

Frequently asked questions about Pretty Lake

Where is Pretty Lake?

Pretty 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 Pretty Lake?

Pretty Lake in Waukesha County, Wisconsin has a water quality grade of B (Good). Water clarity: 12.2 ft visibility. Phosphorus: 12.2 µg/L. Maximum depth: 31 ft. Surface area: 65 acres.

Is Pretty Lake safe to swim in?

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

What is the water temperature of Pretty Lake?

Pretty Lake typically sits around 79°F at the surface in August, from 29 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Pretty Lake?

Pretty Lake has a maximum depth of 31 feet. The lake covers 65 acres.

What fish are in Pretty Lake?

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

What did the DNR fisheries survey find at Pretty Lake?

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

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

State Parks Near Pretty Lake

Mesotrophic Lakes in Wisconsin

Where this data comes from

124 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_WQX124 samples · 2020–2026

Analytical methods

  • Phosphorus by Colorimetry
  • Total Phosphorus After Block Digestion
  • 2130 B ~ Nephelometric Method
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