Ottawa Lake
Waukesha County, Wisconsin · WBIC 822200
Size
28 acres
Max depth
16 ft
DNR lake type
Complex, Warm, dark water color
Water clarity
9.5 ft
Moderate, measured Aug 2025
A warm-water lake type: the DNR groups it with lakes that warm up through summer. This describes the lake type in general, not this lake in particular.
Outline
Numbered dots are boat landings; tap one for directions. The list below has the same numbers. Drawn from the DNR's 24K hydrography (surveyed 1971), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
9.5 ft Secchi depthModerate
Last measured Aug 25, 2025. 300 readings on record, 2002 to 2025.
Typical summer clarity (June to September): 12.8 ft, clear, from 91 readings (2012 to 2025).
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 OTTAWA LAKE - DEEP HOLE. Checked Oct 23, 2026.
Water temperature
Last measured Aug 25, 2025, too long ago to show as the current temperature.
A typical year Modeled estimate
- Ice goes outabout Apr 4 (Mar 28 to Apr 13)
- Surface reaches 48°Fabout Apr 13 (Apr 3 to Apr 22)
- Surface reaches 64°Fabout May 2 (Apr 20 to May 8)
- June surface76°F, usually 74 to 77°F
- July surface81°F, usually 79 to 83°F
- August surface77°F, usually 74 to 79°F
Forms a warm top layer around May 14, lasting about 95 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 2025 (yearling); stocked in 14 years since 2010
- Northern Pikelast stocked 2021 (large fingerling); stocked in 10 years since 2010
- Walleyelast stocked 2020 (large fingerling and small fingerling); stocked in 2 years since 2010
- Brown Troutlast stocked 2017 (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.
Boat landings
- 1Ottawa LakeBoat ramp · Gravel surface · State(dnr)
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
Fishing from shore
- OTTAWA LAKE FISHING PIERDirections · DNR details
Wisconsin DNR shore fishing sites. Checked Oct 24, 2026.
More lakes in Waukesha County
- Pretty Lake1.4 miles away
- Reagon Lake1.7 miles away
- Larkin Lake2.9 miles away
- School Section Lake3.3 miles away
- Scuppernong Creek Pond3.9 miles away
- Hunters Lake4.2 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
- Boat landingsWisconsin DNR public boat access sites, checked Oct 23, 2026
- Water clarityWisconsin 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
- Shore fishing sitesWisconsin DNR shore fishing sites, 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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