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LakeQuality

Cedar Island Lake

Hennepin County, MinnesotaView mapDirections

Minnesota PCA publishes the water-quality measurements for Cedar Island Lake. Here is what has been measured.

Clarity
3 ft
Murkier than most
Secchi · sampled 2025
Phosphorus
93 µg/L
More phosphorus than most
Measured by Minnesota PCA
Chlorophyll-a
41.8 µg/L
More algae than most
Measured by Minnesota PCA
Water temp
~57°F
Typical for Oct · EPA WQP
Max depth
~35 ft est.
GLOBathy model
Type
Eutrophic
Trophic class
  • Eutrophic
  • Impaired · Nutrients (phosphorus, nitrogen)
  • 35 ft max depth

Cedar Island Lake in Hennepin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 93 µg/L. Chlorophyll-a (algae): 41.8 µg/L.

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Cedar Island Lake is a productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with an estimated average depth of about 35 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. No public access — the lake is private or restricted. Compared to the 80 other monitored lakes in Hennepin County, Cedar Island Lake ranks #71 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-28. Methodology: how these readings are compared.

What Cedar Island Lake is good for

From access and monitoring records, not editorial picks.

  • Ice seasonIce-out around Apr 5

Swimming conditions

Readings only

Recreation use not supported

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.

Nutrient and algae readings are not a swimming clearance. Cedar Island Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Whether Cedar Island Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Cedar Island Lake

These are the measurements Minnesota PCA publishes for Cedar Island Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Very murky, less than 3 ft of visibility. Phosphorus 93 µg/L. Chlorophyll-a 41.8 µg/L. TSI 66.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)3ftMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus93µg/LPoor
GoodFairPoor
Chlorophyll-a (algae)41.8µg/LPoor
GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.66Eutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

High nutrients, frequent algae, reduced clarity

Ask about Cedar Island Lake

Answers come straight from the public measurements and survey records on this page.

Water Temperature

Cedar Island Lake typically sits around 57°F at the surface in October. Summer average is about 77°F. Usually warmest in Jul (about 79°F) and coldest in Oct (about 57°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
69°
May
76°
Jun
79°
Jul
76°
Aug
68°
Sep
57°
Oct
Nov
Dec

Column height runs from this lake’s coldest month (57°F) to its warmest (79°F).

Typical surface water temperature by month, from 52 field readings (2021–2025) via the EPA Water Quality Portal. See the full Cedar Island Lake water temperature breakdown →

Lake Details

Max depth

~35 ft est.

Public access

No

Listed by Minnesota PCA

Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for Cedar Island Lake.

Lake Size & Watershed

Watershed (drainage) area

1 sq mi

HydroLAKES / HydroSHEDS

Surface area

79 acres

HydroLAKES / HydroSHEDS

Shoreline

2 mi

HydroLAKES / HydroSHEDS

Elevation

896 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.

Stays via Stay22

Stays near Cedar Island Lake

Compare lakeside cabins, hotels, and vacation rentals near Cedar Island Lake in Hennepin County, Minnesota — 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Cedar Island Lake are listed below.

Top-rated places to stay near Cedar Island Lake

Prices for Oct 9–11, 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 whole trip? See where to stay at Minnesota’s top lakes →

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Fishing Cedar Island Lake

Based on 6 years of monitoring (2020–2025).

  • Water clarity

    Improving

    6 years

  • Phosphorus

    Stable

    -0.33 µg/L/yr2 years

  • Chlorophyll-a

    Stable

    -0.1 µg/L/yr2 years

See year-by-year chart →

Ice season

Typical ice-out

Apr 5

Earliest Mar 6, 2000 · Latest Apr 25, 1975

Typical ice-in

Nov 24

Earliest Nov 3, 1995 · Latest Dec 21, 1999

Most recent ice-out

Apr 8

2019

73 observations · Minnesota PCA ice records

EPA Impairment Status

Cedar Island Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Designated uses not supporting: Recreation.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN27-0119-00 · Official waterbody report

Nearby Lakes in Hennepin County

Frequently asked questions about Cedar Island Lake

Where is Cedar Island Lake?

Cedar Island Lake is a lake in Hennepin County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.

What is the water quality of Cedar Island Lake?

Cedar Island Lake in Hennepin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 93 µg/L. Chlorophyll-a (algae): 41.8 µg/L.

Measurements on this page ↑

Is Cedar Island Lake safe to swim in?

Nutrient and algae readings are not a swimming clearance. Cedar Island Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.

Swimming on this page ↑

What is the water temperature of Cedar Island Lake?

Cedar Island Lake typically sits around 57°F at the surface in October, from 52 EPA Water Quality Portal field readings (2021–2025). That is a typical value for the month, not a live reading.

Temp on this page ↑

How deep is Cedar Island Lake?

No published bathymetric survey covers Cedar Island Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 35 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

When does Cedar Island Lake thaw?

Cedar Island Lake typically has ice-out around Apr 5. Ice typically forms around Nov 24. The open water season is approximately 233 days.

Can I fish at Cedar Island Lake?

Public access to Cedar Island Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.

State Parks Near Cedar Island Lake

Eutrophic Lakes in Minnesota

Where this data comes from

166 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA166 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • Analysis of Chlorophyll in Periphyton and Plankton
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (2)

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

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

Ice data from Minnesota DNR Climate