Lower Nashotah Lake
Waukesha County, Wisconsin · WBIC 827300
Size
90 acres
Max depth
43 ft
DNR lake type
Complex, Two Story
Water clarity
16 ft
Clear, measured Sep 2026
A deep lake type that can hold a cold layer below the warm surface in summer. This describes the lake type in general, not this lake in particular.
Outline
Drawn from the DNR's 24K hydrography (surveyed 1976), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
16 ft Secchi depthClear
Last measured Sep 23, 2026. 98 readings on record, 1987 to 2026.
Typical summer clarity (June to September): 10 ft, clear, from 59 readings (2018 to 2026).
Secchi depth is how far down a white disk stays visible. A bigger number means clearer water. Clear means a Secchi depth of 10 feet or more, moderate 5 to 10 feet, low under 5 feet.
Wisconsin DNR water monitoring (volunteer and staff), via the Water Quality Portal; station LOWER NASHOTAH LAKE - DEEP HOLE. Checked Oct 23, 2026.
Water temperature
68°F surface, measured Oct 9, 2026
Measured near the surface (0.91 m down). A single reading, not a daily value.
A typical year Modeled estimate
- Ice goes outabout Apr 10 (Mar 30 to Apr 14)
- Surface reaches 48°Fabout Apr 20 (Apr 11 to Apr 25)
- Surface reaches 64°Fabout May 11 (May 5 to May 18)
- June surface75°F, usually 74 to 76°F
- July surface81°F, usually 79 to 82°F
- August surface77°F, usually 74 to 79°F
Forms a warm top layer around Apr 21, lasting about 184 days.
A computer model of this lake's typical weather and water, built from 15 years, 2005 to 2019. Ranges show the middle half of years. The model was not calibrated against measured temperatures for this lake. It is an estimate, not a measurement.
Measured: Wisconsin DNR via the Water Quality Portal (checked Oct 23, 2026). Modeled: U.S. Geological Survey lake temperature data release (doi:10.5066/P9CA6XP8).
Today at the lake
Forecast: National Weather Service (no endorsement implied). Sunrise, sunset and moon phase are calculated. The moon phase can be a day off.
Stocking history
- Rainbow Troutlast stocked 2021 (yearling); stocked in 11 years since 2010
- Brown Troutlast stocked 2018 (yearling); stocked in 4 years since 2010
Stocking shows what was added to the lake, not what is in it now.
Wisconsin DNR annual fish stocking summary. Checked Oct 23, 2026.
More lakes in Waukesha County
- Upper Nemahbin Lake0.7 miles away
- Upper Nashotah Lake0.7 miles away
- Applebecker Millpond1.3 miles away
- Crooked Lake1.8 miles away
- Oconomowoc Lake1.8 miles away
- Lower Nemahbin Lake1.8 miles away
Where this comes from
- Size, depth and lake typeWisconsin DNR lake classifications, checked Oct 23, 2026
- OutlineWisconsin DNR 24K hydrography, checked Oct 23, 2026
- Stocking historyWisconsin DNR annual fish stocking summary, checked Oct 23, 2026
- Regulations linkWisconsin DNR fishing regulations (linked, not restated), checked Oct 23, 2026
- Water clarityWisconsin DNR water monitoring, via the Water Quality Portal, checked Oct 23, 2026
- Measured temperatureWisconsin DNR water monitoring, via the Water Quality Portal, checked Oct 23, 2026
- Typical-year temperatureU.S. Geological Survey lake temperature model (modeled estimate), checked Oct 23, 2026
- VHS statusWisconsin DNR VHS status by watershed, checked Oct 24, 2026
- Depth map linkWisconsin DNR lake maps list, checked Oct 24, 2026
See data sources for what each source covers, and about for how the numbers are matched to lakes.
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