Geneva Lake
Walworth County, Wisconsin5,401 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Geneva Lake. Here is what has been measured.
- Oligotrophic
- 3 aquatic invasives
- 135 ft max depth
- Public access
Geneva Lake in Walworth County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 21 ft visibility. Phosphorus: 13 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 135 ft. Surface area: 5401 acres.
Wisconsin DNR rates Smallmouth Bass as abundant on Geneva Lake. DNR survey details →
Geneva Lake is a 5,401-acre cold, clear oligotrophic lake in Walworth County, Wisconsin with a maximum depth of 135 feet. The lake supports 6 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 6 public boat landings and 6 public beaches. Compared to the 18 other monitored lakes in Walworth County, Geneva Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-18. Methodology: how these readings are compared.
At about 5,400 acres, Geneva Lake is large enough that where you stay decides which shore you see most of. It has 6 public boat landings, so a lakefront rental is not the only way to get a boat on the water. For a place on the water, look through cabin and lake-house rentals near Geneva Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Geneva Lake is good for
From access and monitoring records, not editorial picks.
- Clear water21 ft of visibility
- Boat launch6 documented ramps
- Beach6 documented beaches
- Fishing6 species recorded
- Deep water135 ft surveyed max depth
- Big water5,401 acres
Geneva Lake Water Quality Summary (2026)
A printable one-page summary for Geneva Lake: clarity, phosphorus, algae, multi-year trend, depth, and fish — with sources.
Swimming conditions
Readings onlyBacteria tested: low
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.
Based on E. coli testing, Geneva Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 4.1% of 579 samples across 9 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Wisconsin’s current beach and health-department advisories before swimming.
Whether Geneva 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 Geneva Lake
These are the measurements Wisconsin DNR publishes for Geneva Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 21 ft down. Phosphorus 13 µg/L. Chlorophyll-a 2.1 µg/L. TSI 37.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 21ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 13µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.1µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 37 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Geneva Lake
Answers come straight from the public measurements and survey records on this page.
Current Conditions
USGS snapshot Jul 6, 2026, 5:00 AM from gauge 423525088260400 (Geneva Lake at Lake Geneva, WI). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Geneva Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (6,855 cells/mL) on November 17, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR rates Smallmouth Bass as abundant on Geneva Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Geneva Lake’s water-quality measurements separately. 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. 15 stations on file (most recent sample 2026).
Fish Species (DNR-rated)
Lake Details
Max depth
135 ft
Surface area
5,401 acres
Public access
Yes
Listed by Wisconsin DNR
Recreation & Access
- Linn RoadPublic
- FontanaPublic
- Williams BayPublic
- Chapin RoadPublic
- Abbey MarinaSemi-private
- Abbey Springs Yacht ClubSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Geneva Lake
Compare lakeside cabins, hotels, and vacation rentals near Geneva Lake in Walworth 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 Geneva Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip? Cabins and lodging at Geneva Lake → · more Wisconsin lake trips
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Fish Species
Click a species to see every lake where it is documented.
Fishing Geneva 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.
Nearby Lakes in Walworth County
Frequently asked questions about Geneva Lake
Where is Geneva Lake?
- Geneva Lake is a lake in Walworth County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Geneva Lake?
- Geneva Lake in Walworth County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 21 ft visibility. Phosphorus: 13 µg/L. Chlorophyll-a (algae): 2.1 µg/L. Maximum depth: 135 ft. Surface area: 5401 acres.
Is Geneva Lake safe to swim in?
- Based on E. coli testing, Geneva Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 4.1% of 579 samples across 9 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Geneva Lake is safe to swim in today is a call for Wisconsin's water agency and the county health department; check their current beach advisories before you swim.
How deep is Geneva Lake?
- Geneva Lake has a maximum depth of 135 feet. The lake covers 5401 acres.
What fish are in Geneva Lake?
- Fish species found in Geneva Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Trout, Walleye. Geneva Lake is located in Walworth County, Wisconsin.
What did the DNR fisheries survey find at Geneva Lake?
- Wisconsin DNR rates Smallmouth Bass as abundant on Geneva Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Geneva Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
What is the water level at Geneva Lake?
- The USGS snapshot on this page for Geneva Lake is 864.13 ft of water-surface elevation, recorded Jul 6, 2026, 5:00 AM at gauge 423525088260400. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
Does Geneva Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Geneva Lake (clouds, ice, or an off-season gap). The most recent reading was low (6,855 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Geneva Lake?
- Geneva Lake has 6 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Linn Road, Fontana, Williams Bay, Chapin Road, among others. Public access is listed as yes.
Can I fish at Geneva Lake?
- Geneva Lake has 6 documented boat landings in the USGS National Boat Ramps inventory. 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 Geneva Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Wisconsin
Fish species and best lakes in Walworth County
Species activity outlook by water temperature and season
Where to stay at Wisconsin's top lakes, each with its readings
Wisconsin's cleanest lakes, ranked on agency measurements
More lakes in Wisconsin
State Parks Near Geneva Lake
Other Lakes in Wisconsin
Oligotrophic Lakes in Wisconsin
Compare Geneva Lake With Nearby Lakes
Where this data comes from
333 measurements from 3 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX197 samples · 2020–2026 - USGS Wisconsin Water Science Center
USGS-WI136 samples · 2020–2023
Analytical methods
- Phosphorus by Colorimetry
- Turbidity in Water
Monitoring station identifiers (3)
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
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory