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Perch Lake

Oneida County, WisconsinMesotrophic

Perch Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oneida County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Mesotrophic conditions dominate at Perch Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Perch Lake is unusually deep for Wisconsin at 56 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. The lake is compact at 34 acres, with partial shoreline records and little volume to buffer nutrient inputs. Perch Lake ranks 8 of 134 in Oneida County, putting it in the upper tier of locally monitored lakes.

Perch Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Bass fishing is part of the appeal: the species list runs to 2, anchored by largemouth and/or smallmouth bass. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-17. Grade methodology: LakeGrade methodology.

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Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 15 ft down. Phosphorus level: 14.5 µg/L. Trophic State Index: 40.

MetricValueGrade
Water Clarity (Secchi Depth)15 ftA
Phosphorus14.5 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)40Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth56 ft
Surface Area34 acres
Public AccessYes

Fish Species

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

→ Best fishing times for Perch Lake (14-day solunar calendar)

→ Is it safe to eat fish from Perch Lake? (mercury & PFAS guide)

Perch Lake fishing regulations (limits, seasons, special rules)

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 Snail

Water Quality Trend: Declining

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

MetricTrendChange/YearYears
Water Clarity Stable+0.082 m/yr7
Phosphorus Declining+0.93 µg/L/yr6
See year-by-year chart →

Recreation & Access

6
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #8 of 134 lakes in Oneida County

Nearby Lakes in Oneida County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2002. 1 station on file (most recent sample 2025).

DNR Assessment
Excellent · Deep Seepage lake
Trophic State Index 42 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Present)Largemouth Bass(Present)

EPA Impairment Status

Perch Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit WI10007349 · Official waterbody report · Matched by proximity (1.66 km)

Data Sources

Water quality data from the EPA Water Quality Portal

Impairment status from EPA ATTAINS 303(d) database

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

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

Most recent sample: 2025-08-17

Monitoring stations: 1

Where to stay near Perch Lake

Compare lakeside cabins, hotels, and vacation rentals near Perch Lake in Oneida County, Wisconsin — live availability and prices for your trip.

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