Forest Lake
Waukesha County, Wisconsin · WBIC 775800
Size
41 acres
Max depth
17 ft
DNR lake type
Simple, Warm, dark water color
Water clarity
10.5 ft
Clear, measured Feb 1981
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 1976), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
10.5 ft Secchi depthClearOlder reading
Last measured Feb 17, 1981. 1 reading on record, 1981.
Only one reading is on record.
Nothing has been measured in the last 5 years, so this may not match the lake today.
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 FOREST LAKE - DEEP HOLE. Checked Oct 23, 2026.
Water temperature
A typical year Modeled estimate
- Ice goes outabout Apr 8 (Mar 29 to Apr 12)
- Surface reaches 48°Fabout Apr 12 (Apr 4 to Apr 22)
- Surface reaches 64°Fabout May 5 (Apr 25 to May 12)
- June surface74°F, usually 73 to 75°F
- July surface80°F, usually 78 to 82°F
- August surface76°F, usually 74 to 79°F
Forms a warm top layer around May 5, lasting about 96 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.
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.
Fish recorded near this lake
- Bluegill Lepomis macrochirus2022; 1 record
- Northern Pike Esox lucius2022; 1 record
Recorded in open fish survey and museum records (GBIF). A record shows a fish was found near this lake in that year, not that it is there now, and says nothing about how many. Most coordinates are rounded to about 1 km, so a record is attached only when one lake is the clear match.
Open fish survey and museum records from GBIF; datasets are listed on the sources page. Checked Oct 23, 2026.
Boat landings
- 1Forest Lake Carry-InCarry-in access · Unimproved surface · County
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
More lakes in Waukesha County
- Grass Lake0.6 miles away
- Garvin Lake1.1 miles away
- Pine Lake1.5 miles away
- Florence Lake1.6 miles away
- Okauchee Lake1.6 miles away
- Upper Nashotah 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
- 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
- Fish recordedOpen fish survey and museum records, via GBIF, 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.
Something wrong on this page? Report a problem.