Rockville Flowage
Manitowoc County, Wisconsin · WBIC 58400
The DNR lists this lake's watershed (Sheboygan River-Frontal Lake Michigan) as suspect or infected with VHS, a fish virus. The listing covers the watershed, not a test of this lake. About VHS
Size
110 acres
Max depth
6 ft
DNR lake type
Simple, Riverine
Water clarity
4 ft
Low, measured Jul 1995
A river-like water type, with flow instead of a still basin. 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 1992), so the shape is approximate and a landing can sit a little off the shore. Open the DNR lake map.
Water clarity
4 ft Secchi depthLowOlder reading
Last measured Jul 2, 1995. 3 readings on record, 1995.
Only a few readings are on record.
Nothing has been measured in the last 5 years, so this may not match the lake today.
Measured at the monitoring station named “ROCKVILLE IMPOUNDMENT - ROCKVILLE IMPOUNDMENT”.
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 ROCKVILLE IMPOUNDMENT - ROCKVILLE IMPOUNDMENT. Checked Oct 23, 2026.
Water temperature
A typical year Modeled estimate
- Ice goes outabout Apr 4 (Mar 29 to Apr 11)
- Surface reaches 48°Fabout Apr 13 (Apr 3 to Apr 19)
- Surface reaches 64°Fabout May 11 (May 2 to May 20)
- June surface73°F, usually 73 to 75°F
- July surface79°F, usually 77 to 81°F
- August surface75°F, usually 73 to 77°F
Mixes regularly through the summer instead of forming a warm top layer.
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.
Boat landings
- 1Sisson Park Boat RampBoat ramp · Gravel surface · City
Directions
Wisconsin DNR public boat access sites. Checked Oct 23, 2026.
More lakes in Manitowoc County
- Prueder Lake1.8 miles away
- Shoe Lake1.8 miles away
- Graf Lake1.9 miles away
- Mud Lake2.6 miles away
- Cedar Lake3.5 miles away
- Sy Lake4.1 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
- 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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