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LakeQuality

Coon Lake

C
Grade C — Fair
Fair · #9 of 23 lakes in the county · 5.7 ft clear · Eutrophic · 1,481 acres
Limited DataEutrophic

Coon Lake in Anoka County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.7 ft visibility. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 7.9 µg/L. Maximum depth: 27 ft. Surface area: 1481.24 acres.

Clarity
5.7 ft
Typical in August
84°F
Max depth
27 ft
Area
1,481 acres
Type
Eutrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 4
Open water
235 days

Next lake in Anoka County

CBoot Lake6.7 ft clear · Anoka CountyView →
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Free interactive depth-contour map of Coon Lake, reaching a maximum surveyed depth of 25 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.

Coon Lake is a 1,481-acre productive, nutrient-rich eutrophic lake in Anoka County, Minnesota with a maximum depth of 27 feet (10-foot average). Water quality is graded C based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 2 public boat landings. Compared to the 22 other monitored lakes in Anoka County, Coon Lake ranks #9 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-12. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Limited data

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 Minneapolis

Get alerts for Coon Lake

Water Quality Grade: C (Fair)

Murky, only visible to about 5.7 ft. Phosphorus level: 23 µg/L. Chlorophyll-a: 7.9 µg/L. Trophic State Index: 51.

MetricValueGrade
Water Clarity (Secchi Depth)5.7 ftNot graded
Phosphorus23 µg/LGood
Chlorophyll-a (Algae)7.9 µg/LFair
Trophic State Index (TSI)51Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Coon Lake

Compare lakeside cabins, hotels, and vacation rentals near Coon Lake in Anoka 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.

Top-rated places to stay near Coon 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 Minnesota’s top lakes →

Water Temperature

Coon Lake typically sits around 84°F at the surface in August. Summer average is about 81°F. Usually warmest in Jul (about 85°F) and coldest in May (about 64°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
64°
Jun
74°
Jul
85°
Aug
84°
Sep
75°
Oct
69°
Nov
Dec

Typical surface water temperature by month, from 65 field readings (20222025) via the EPA Water Quality Portal. See the full Coon Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth27 ft
Average Depth10 ft
Surface Area1,481 acres
Shoreline Length16.3 mi
Littoral Zone74%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
33 sq mi
Elevation
886 ft

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

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Coon LakePublic
  • County Road 17Public

Fish Species

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

Fishing Coon 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.

Eurasian watermilfoil

DNR Fisheries Survey Summary

17 surveys on file from MN DNR Fisheries. Most recent: 2025-06-16 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill48.230.11 lb
Black Bullhead26.250.51 lb
Black Crappie15.690.16 lb
Pumpkinseed7.820.12 lb
Northern Pike6.832.34 lb
Brown Bullhead6.070.58 lb

CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.

Length Distributions

Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.

Bluegill

627 fish · 27 in · 2025-06-16
3571790234567

Black Bullhead

13 fish · 714 in · 2025-06-16
4207891011121314

Black Crappie

53 fish · 411 in · 2025-06-16
22110trophy 104567891011

Pumpkinseed

107 fish · 37 in · 2025-06-16
6231034567

From the 2025-06-16 survey

Coon Lake is a 1,250 acre lake located in northern Anoka County and assigned to lake class 35. There are two major basins with the eastern one being the deeper but smaller of the two. This lake was historically susceptible to winterkills but there are currently two aeration systems in place which appear to be…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Coon Lake. 3 reports on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.071 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (32 observations).

Typical Ice-Out
Apr 4
Typical Ice-In
Nov 25

Estimated open water season: 235 days

EarliestLatest
Ice-Out2016-03-15 (2016)2018-05-01 (2018)
Ice-In2002-11-15 (2002)2001-12-20 (2001)

Most recent ice-out: 2025-03-22

EPA Impairment Status

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

Causes of impairment

Mercury

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

Source: EPA ATTAINS assessment unit MN02-0042-00 · Official waterbody report

County Ranking

Ranked #9 of 23 lakes in Anoka County

Nearby Lakes With Higher Grades

Coon 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.

Nearby Lakes in Anoka County

Frequently asked questions about Coon Lake

What is the water quality grade for Coon Lake?

Coon Lake in Anoka County, Minnesota has a water quality grade of C (Fair). Water clarity: 5.7 ft visibility. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 7.9 µg/L. Maximum depth: 27 ft. Surface area: 1481.24 acres.

Is Coon Lake safe to swim in?

Generally safe for swimming, moderate water quality. Coon Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 7.9 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Coon Lake?

Coon Lake typically sits around 84°F at the surface in August, from 65 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.

How deep is Coon Lake?

Coon Lake has a maximum depth of 27 feet and an average depth of 10 feet. The lake covers 1481.24 acres.

What fish are in Coon Lake?

Fish species found in Coon Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Coon Lake is located in Anoka County, Minnesota.

When does Coon Lake thaw?

Coon Lake typically has ice-out around Apr 4. Ice typically forms around Nov 25. The open water season is approximately 235 days.

Are there boat ramps on Coon Lake?

Coon Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Coon Lake, County Road 17. Public access is listed as yes.

Where this data comes from

278 measurements from 6 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 WaterMNPCA278 samples · 2020–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
  • Turbidity, Nephelometric Method
Monitoring station identifiers (6)

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

Impairment status from EPA ATTAINS 303(d) database

Lake size & watershed from HydroLAKES (HydroSHEDS)

Lake details from Minnesota DNR LakeFinder

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

Ice data from Minnesota DNR Climate