Skip to main content
LakeQuality
C

Cedar Lake

Polk County, WisconsinEutrophic

Cedar Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake bottoms out at 32 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 1,120 acres, Cedar Lake is one of the larger lakes in Polk County, with partial shoreline records supporting multiple distinct use patterns. Cedar Lake ranks 69 of 77 in Polk County — at the lower end of the locally monitored distribution.

Eurasian watermilfoil has been documented at Cedar Lake, requiring shoreline management to keep dense mats from crowding native vegetation. The fishery includes walleye alongside the lake's other 5 documented species — a notable draw for Wisconsin anglers. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-08. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Murky, only visible to about 6.2 ft. Phosphorus level: 42.3 µg/L. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)6.2 ftD
Phosphorus42.3 µg/LC
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth32 ft
Surface Area1.1K acres
Public AccessYes

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

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

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

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

Invasive Species

Chinese Mystery SnailCurly-Leaf PondweedEurasian Water-MilfoilJapanese knotweedRusty Crayfish

Water Quality Trend: Improving

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

MetricTrendChange/YearYears
Water Clarity Improving+0.517 m/yr7
Phosphorus Improving-1.44 µg/L/yr6
See year-by-year chart →

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

Loading map…

County Ranking

Ranked #69 of 77 lakes in Polk County

Cleaner Lakes Within 30 Miles

Cedar Lake holds Grade C. 5 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Polk County

Eutrophic Lakes in Wisconsin

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 2 stations on file (most recent sample 2025).

DNR Assessment
Good · Shallow Lowland lake
Trophic State Index 61 (eutrophic) · 5-year average

Fish Species (DNR-rated)

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

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-09-08

Monitoring stations: 3