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Shadow Lake

Waupaca County, WisconsinMesotrophic

On the LakeGrade rubric, Shadow Lake pulls an A: clarity at 12.0 ft and 12 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 41 ft puts Shadow Lake in the middle of Wisconsin's depth distribution. The lake is compact at 44 acres, with partial shoreline records and little volume to buffer nutrient inputs. Shadow Lake ranks 10 of 25 in Waupaca County — solidly in the upper half of the local distribution.

Zebra mussels have been documented at Shadow Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. The fishery includes walleye alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. 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 2026-04-20. Grade methodology: LakeGrade methodology.

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Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Good clarity, visible to about 12 ft. Phosphorus level: 11.9 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)12 ftB
Phosphorus11.9 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth41 ft
Surface Area44 acres
Public AccessYes

Fish Species

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

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

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

Shadow 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.

Banded Mystery SnailCurly-Leaf PondweedEurasian Water-MilfoilPurple LoosestrifeZebra Mussel

Water Quality Trend: Improving

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.5 m/yr2
Phosphorus Improving-10.06 µg/L/yr3

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #10 of 25 lakes in Waupaca County

Nearby Lakes in Waupaca County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

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

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Shadow Lake covering fish populations, stocking, water quality, and management. 1 report on file.

EPA Impairment Status

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

Causes of impairment

Cause unknown

Source: EPA ATTAINS assessment unit WI10000421 · Official waterbody report

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: 2026-04-20

Monitoring stations: 1

Where to stay near Shadow Lake

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

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