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LakeQuality

Kathan Lake

C
Grade C — Fair
Fair · #54 of 67 lakes in the county · 2.7 ft clear · Eutrophic · 214 acres
Eutrophic

Kathan Lake in Oneida County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.7 ft visibility. Phosphorus: 29.8 µg/L. Maximum depth: 15 ft. Surface area: 214 acres.

Wisconsin DNR lists Panfish as common on Kathan Lake. DNR survey details →

Clarity
2.7 ft
Max depth
15 ft
Area
214 acres
Type
Eutrophic
Trend
Improving
Public access
Yes

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Kathan Lake is a 214-acre productive, nutrient-rich eutrophic lake in Oneida County, Wisconsin with a maximum depth of 15 feet. Water quality is graded C based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 66 other monitored lakes in Oneida County, Kathan Lake ranks #54 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-21. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Moderate

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Generally safe for swimming, moderate water quality

Compare the safest swimming lakes near Eagle River

Get alerts for Kathan Lake

Water Quality Grade: C (Fair)

Very murky, less than 2.7 ft of visibility. Phosphorus level: 29.8 µg/L. Trophic State Index: 58.

MetricValueGrade
Water Clarity (Secchi Depth)2.7 ftNot graded
Phosphorus29.8 µg/LFair
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)58Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Kathan Lake

Compare lakeside cabins, hotels, and vacation rentals near Kathan Lake in Oneida 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 Kathan Lake

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 whole trip? See where to stay at Wisconsin’s top lakes →

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Kathan Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Kathan Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. 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 1993. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

Panfish(Common)Northern Pike(Common)Musky(Present)Largemouth Bass(Present)Walleye(Present)

Lake Details

CharacteristicValue
Maximum Depth15 ft
Surface Area214 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
2 sq mi
Shoreline
3.2 mi
Elevation
1,631 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Chain LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Kathan 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.

Chinese Mystery SnailEurasian Water-Milfoil

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.129 m/yr7
Phosphorus Stable-0.3 µg/L/yr6
See year-by-year chart →

County Ranking

Ranked #54 of 67 lakes in Oneida County

Nearby Lakes With Higher Grades

Kathan Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Oneida County

Frequently asked questions about Kathan Lake

Where is Kathan Lake?

Kathan Lake is a lake in Oneida County, Wisconsin. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Kathan Lake?

Kathan Lake in Oneida County, Wisconsin has a water quality grade of C (Fair). Water clarity: 2.7 ft visibility. Phosphorus: 29.8 µg/L. Maximum depth: 15 ft. Surface area: 214 acres.

Is Kathan Lake safe to swim in?

Generally safe for swimming, moderate water quality. Kathan Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.

How deep is Kathan Lake?

Kathan Lake has a maximum depth of 15 feet. The lake covers 214 acres.

What fish are in Kathan Lake?

Fish species found in Kathan Lake include Musky, Panfish, Largemouth Bass, Northern Pike, Walleye. Kathan Lake is located in Oneida County, Wisconsin.

What did the DNR fisheries survey find at Kathan Lake?

Wisconsin DNR lists Panfish as common on Kathan Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Kathan Lake C from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

Are there boat ramps on Kathan Lake?

Kathan Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Chain Lake. Public access is listed as yes.

Where this data comes from

39 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX39 samples · 2020–2025

Analytical methods

  • Phosphorus by Colorimetry
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Lake size & watershed from HydroLAKES (HydroSHEDS)

Fish and recreation data from Wisconsin DNR Lakes

Named boat-access points from the USGS National Boat Ramps inventory