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LakeQuality

Duck Lake

A
Grade A — Excellent
Excellent · #41 of 85 lakes in the county · 9 ft clear · Mesotrophic · from B
Limited DataMesotrophic

Duck Lake in Crow Wing County, Minnesota has a water quality grade of A (Excellent). Water clarity: 9 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 3 µg/L.

Clarity
9 ft
Typical in August
72°F
Mean depth
~12 ft est.
Type
Mesotrophic
Trend
Stable
Public access
Yes

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Duck Lake is a mesotrophic lake in Crow Wing County, Minnesota with an estimated average depth of about 12 feet. Water quality is graded A based on 2 sampling years through 2025. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 84 other monitored lakes in Crow Wing County, Duck Lake ranks #41 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-24. 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.

Excellent for swimming, crystal clear water with minimal algae

Compare the safest swimming lakes near Brainerd

Get alerts for Duck Lake

Water Quality Grade: A (Excellent)

Moderate clarity, visible to about 9 ft. Phosphorus level: 13.5 µg/L. Chlorophyll-a: 3 µg/L. Trophic State Index: 43.

MetricValueGrade
Water Clarity (Secchi Depth)9 ftNot graded
Phosphorus13.5 µg/LGood
Chlorophyll-a (Algae)3 µg/LGood
Trophic State Index (TSI)43Mesotrophic

Moderate nutrients, good water quality

Where to stay near Duck Lake

Compare lakeside cabins, hotels, and vacation rentals near Duck Lake in Crow Wing 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 Duck 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

Duck Lake typically sits around 72°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 75°F) and coldest in Sep (about 66°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
68°
Jun
74°
Jul
75°
Aug
72°
Sep
66°
Oct
Nov
Dec

Typical surface water temperature by month, from 26 field readings (20232025) via the EPA Water Quality Portal. See the full Duck Lake water temperature breakdown →

Lake Details

CharacteristicValue
Average Depth~12 ft est.
Public AccessYes

Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Duck Lake.

Lake Size & Watershed

Watershed (drainage) area
1 sq mi
Surface area
126 acres
Mean depth (modeled estimate)
~12 ft est.
Shoreline
3 mi
Elevation
1,224 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.

Recreation & Access

3
Boat Landings
Yes
Public Access
  • Ossawinnamakee LakePublic
  • Halverson BayPublic
  • Cross Lake #1Public

Fishing Duck Lake

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Duck Lake. 2 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 Stable+0.025 m/yr6
Phosphorus Stable-0.06 µg/L/yr6
Chlorophyll-a Stable-0.01 µg/L/yr6
See year-by-year chart →

EPA Impairment Status

Duck 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 MN18-0312-03 · Official waterbody report · Matched by proximity (2.34 km)

County Ranking

Ranked #41 of 85 lakes in Crow Wing County

Nearby Lakes in Crow Wing County

Frequently asked questions about Duck Lake

What is the water quality grade for Duck Lake?

Duck Lake in Crow Wing County, Minnesota has a water quality grade of A (Excellent). Water clarity: 9 ft visibility. Phosphorus: 13.5 µg/L. Chlorophyll-a (algae): 3 µg/L.

Is Duck Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Duck Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Duck Lake?

Duck Lake typically sits around 72°F at the surface in August, from 26 EPA Water Quality Portal field readings (2023–2025). That is a typical value for the month, not a live reading.

How deep is Duck Lake?

No published bathymetric survey covers Duck Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 12 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.

Are there boat ramps on Duck Lake?

Duck Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Ossawinnamakee Lake, Halverson Bay, Cross Lake #1. Public access is listed as yes.

Where this data comes from

30 measurements from 1 monitoring station, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA30 samples · 2022–2025

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (1)

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