Rock Lake
Kenosha County, Wisconsin44 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Rock Lake. Here is what has been measured.
- Mesotrophic
- Purple Loosestrife
- 33 ft max depth
- Public access
- Limited data
Rock Lake in Kenosha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 15.9 µg/L. Maximum depth: 33 ft. Surface area: 44 acres.
Wisconsin DNR lists Largemouth Bass as common on Rock Lake. DNR survey details →
Rock Lake is a 44-acre mesotrophic lake in Kenosha County, Wisconsin with a maximum depth of 33 feet. Overall water quality is declining over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Trout. Public access is available. Compared to the 7 other monitored lakes in Kenosha County, Rock Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-23. Methodology: how these readings are compared.
Rock Lake covers about 44 acres in Kenosha County. Vrbo is where to look for cabins and lake homes around Rock Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Rock Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10 ft of visibility
- Fishing3 species recorded
- Deep water33 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Rock Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Rock Lake
These are the measurements Wisconsin DNR publishes for Rock Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10 ft. Phosphorus 15.9 µg/L. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 15.9µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Rock Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Rock Lake typically sits around 73°F at the surface in September. Summer average is about 81°F. Usually warmest in Jul (about 81°F) and coldest in May (about 69°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (69°F) to its warmest (81°F).
Typical surface water temperature by month, from 12 field readings (2024–2025) via the EPA Water Quality Portal. See the full Rock Lake water temperature breakdown →
Wisconsin DNR lists Largemouth Bass as common on Rock Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rock Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is declining. 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 2018. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
33 ft
Surface area
44 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
0 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.1 mi
HydroLAKES / HydroSHEDS
Elevation
758 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Rock Lake
Compare lakeside cabins, hotels, and vacation rentals near Rock Lake in Kenosha 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 Rock Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Rock 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.
Water Quality Trend: Worsening
Based on 7 years of monitoring (2020–2026).
Water clarity
Stable7 years
Phosphorus
Worsening+0.4 µg/L/yr3 years
Reservoir Info (USACE NID)
Rock Lake is a man-made reservoir impounded by the Rock Lake (completed 1929), built primarily for recreation on the OUTLET OF ROCK LAKE; gravity-type dam, 8 ft tall and 100 ft long.
- Surface area
- 44 ac
- Normal storage
- 300 ac-ft
- Max storage
- 350 ac-ft
- Drainage area
- 1 sq mi
- Hazard class
- Low
- Owner
- Valentine, Linda
Source: USACE National Inventory of Dams, NID ID WI00268 · Operator website
Nearby Lakes in Kenosha County
Frequently asked questions about Rock Lake
Where is Rock Lake?
- Rock Lake is a lake in Kenosha County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Rock Lake?
- Rock Lake in Kenosha County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 15.9 µg/L. Maximum depth: 33 ft. Surface area: 44 acres.
Is Rock Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Rock Lake?
- Rock Lake typically sits around 73°F at the surface in September, from 12 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Rock Lake?
- Rock Lake has a maximum depth of 33 feet. The lake covers 44 acres.
What fish are in Rock Lake?
- Fish species found in Rock Lake include Panfish, Largemouth Bass, Trout. Rock Lake is located in Kenosha County, Wisconsin.
What did the DNR fisheries survey find at Rock Lake?
- Wisconsin DNR lists Largemouth Bass as common on Rock Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Rock Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Rock Lake?
- Public access to Rock Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Rock Lake across LakeQuality
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Where this data comes from
66 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 Resources
WIDNR_WQX66 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes