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LakeQuality

Cottage Lake

A
Grade A — Excellent
Excellent · #42 of 84 lakes in the county · 12 ft clear · Mesotrophic
Limited DataMesotrophic

Cottage Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.1 µg/L.

Clarity
12 ft
Typical in August
75°F
Type
Mesotrophic
Trend
Improving
Public access
Yes

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ALind Lake12.1 ft clear · Becker CountyView →
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Cottage Lake is a mesotrophic lake in Becker County, Minnesota. Water quality is graded A based on 2 sampling years through 2021. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 83 other monitored lakes in Becker County, Cottage Lake ranks #42 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-09-06. 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 Detroit Lakes

Get alerts for Cottage Lake

Water Quality Grade: A (Excellent)

Good clarity, visible to about 12 ft. Phosphorus level: 11 µg/L. Chlorophyll-a: 3.1 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)12 ftNot graded
Phosphorus11 µg/LGood
Chlorophyll-a (Algae)3.1 µg/LGood
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Where to stay near Cottage Lake

Compare lakeside cabins, hotels, and vacation rentals near Cottage Lake in Becker 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 Cottage 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

Cottage Lake typically sits around 75°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in Sep (about 69°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
71°
Jul
77°
Aug
75°
Sep
69°
Oct
Nov
Dec

Typical surface water temperature by month, from 43 field readings (20212021) via the EPA Water Quality Portal. See the full Cottage Lake water temperature breakdown →

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Mac's LandingPublic

Fishing Cottage Lake

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

MetricTrendChange/YearYears
Water Clarity Improving+0.11 m/yr6
Phosphorus Declining+0.69 µg/L/yr6
Chlorophyll-a Improving-0.25 µg/L/yr6
See year-by-year chart →

EPA Impairment Status

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

Causes of impairment

Mercury

Source: EPA ATTAINS assessment unit MN03-0475-00 · Official waterbody report · Matched by proximity (2 km)

County Ranking

Ranked #42 of 84 lakes in Becker County

Nearby Lakes in Becker County

Frequently asked questions about Cottage Lake

What is the water quality grade for Cottage Lake?

Cottage Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 3.1 µg/L.

Is Cottage Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Cottage Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.1 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Cottage Lake?

Cottage Lake typically sits around 75°F at the surface in August, from 43 EPA Water Quality Portal field readings (2021–2021). That is a typical value for the month, not a live reading.

Are there boat ramps on Cottage Lake?

Cottage Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Mac's Landing. Public access is listed as yes.

State Parks Near Cottage Lake

Where this data comes from

22 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Minnesota Pollution Control Agency - Ambient Surface WaterMNPCA22 samples · 2021

Analytical methods

  • Field measurement/observation, generic method
  • Phosphorus by Two Reagent Colorimetry
  • 10200 H ~ Chlorophyll a-b-c Determination
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

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