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LakeQuality

Farm Island Lake

A
Grade A — Excellent
Excellent · #5 of 18 lakes in the county · 11.3 ft clear · Mesotrophic · 2,005 acres
Limited DataMesotrophic

Farm Island Lake in Aitkin County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.3 ft visibility. Phosphorus: 17.5 µg/L. Chlorophyll-a (algae): 3.5 µg/L. Maximum depth: 56 ft. Surface area: 2005.19 acres.

Clarity
11.3 ft
Typical in August
75°F
Max depth
56 ft
Area
2,005 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes
Ice-out
Apr 19
Open water
226 days

Next lake in Aitkin County

ABig Pine Lake17 ft clear · Aitkin CountyView →
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Free interactive depth-contour map of Farm Island Lake, reaching a maximum surveyed depth of 50 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.

Farm Island Lake is a 2,005-acre mesotrophic lake in Aitkin County, Minnesota with a maximum depth of 56 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 17 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 2 public boat landings. Compared to the 17 other monitored lakes in Aitkin County, Farm Island Lake ranks #5 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-19. 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

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Water Quality Grade: A (Excellent)

Good clarity, visible to about 11.3 ft. Phosphorus level: 17.5 µg/L. Chlorophyll-a: 3.5 µg/L. Trophic State Index: 44.

MetricValueGrade
Water Clarity (Secchi Depth)11.3 ftNot graded
Phosphorus17.5 µg/LGood
Chlorophyll-a (Algae)3.5 µg/LGood
Trophic State Index (TSI)44Mesotrophic

Moderate nutrients, good water quality

Where to stay near Farm Island Lake

Compare lakeside cabins, hotels, and vacation rentals near Farm Island Lake in Aitkin 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 Farm Island 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

Farm Island Lake typically sits around 75°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 76°F) and coldest in Apr (about 46°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
46°
May
58°
Jun
71°
Jul
76°
Aug
75°
Sep
69°
Oct
53°
Nov
Dec

Typical surface water temperature by month, from 43 field readings (20222025) via the EPA Water Quality Portal. See the full Farm Island Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth56 ft
Surface Area2,005 acres
Shoreline Length14.6 mi
Littoral Zone44%
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
18 sq mi
Elevation
1,237 ft

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

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Farm Island NorthPublic
  • Farm Island LakePublic

Fish Species

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

Fishing Farm Island 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.

zebra mussel

DNR Fisheries Survey Summary

34 surveys on file from MN DNR Fisheries. Most recent: 2025-10-07 (Targeted Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluntnose Minnow33.32
Walleye19.131.34 lb
Yellow Perch12.340.13 lb
SDS12.00
Bluegill11.080.18 lb
Spottail Shiner10.75

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.

Bluntnose Minnow

29 fish · 12 in · 2000-07-31
2814012

Walleye

19 fish · 1220 in · 2025-10-07
530121314151617181920

Yellow Perch

4 fish · 59 in · 2025-08-11
21056789

SDS

24 fish · 12 in · 2000-07-31
137012

From the 2025-10-07 survey

Fall night electrofishing (EW) is conducted annually to assess Walleye recruitment by monitoring the abundance of young-of-the-year (YOY) and yearling (age-1) Walleye. Previous fry stocking assessments have occurred on Farm Island Lake (2010-2016) via fall night electrofishing. In these assessments, it was concluded…

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 Farm Island Lake. 4 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+0.323 m/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (105 observations).

Typical Ice-Out
Apr 19
Typical Ice-In
Dec 1

Estimated open water season: 226 days

EarliestLatest
Ice-Out2024-03-14 (2024)2013-05-13 (2013)
Ice-In2014-11-17 (2014)2001-12-20 (2001)

Most recent ice-out: 2025-04-12

EPA Impairment Status

Farm 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

Mercury

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

Source: EPA ATTAINS assessment unit MN01-0159-00 · Official waterbody report

County Ranking

Ranked #5 of 18 lakes in Aitkin County

Nearby Lakes in Aitkin County

Frequently asked questions about Farm Island Lake

What is the water quality grade for Farm Island Lake?

Farm Island Lake in Aitkin County, Minnesota has a water quality grade of A (Excellent). Water clarity: 11.3 ft visibility. Phosphorus: 17.5 µg/L. Chlorophyll-a (algae): 3.5 µg/L. Maximum depth: 56 ft. Surface area: 2005.19 acres.

Is Farm Island Lake safe to swim in?

Excellent for swimming, crystal clear water with minimal algae. Farm Island Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 3.5 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Farm Island Lake?

Farm Island Lake typically sits around 75°F at the surface in August, from 43 EPA Water Quality Portal field readings (2022–2025). That is a typical value for the month, not a live reading.

How deep is Farm Island Lake?

Farm Island Lake has a maximum depth of 56 feet. The lake covers 2005.19 acres.

What fish are in Farm Island Lake?

Fish species found in Farm Island Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, tullibee (cisco), walleye, white sucker, yellow bullhead, yellow perch. Farm Island Lake is located in Aitkin County, Minnesota.

When does Farm Island Lake thaw?

Farm Island Lake typically has ice-out around Apr 19. Ice typically forms around Dec 1. The open water season is approximately 226 days.

Are there boat ramps on Farm Island Lake?

Farm Island Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Farm Island North, Farm Island Lake. Public access is listed as yes.

Mesotrophic Lakes in Minnesota

Compare Farm Island Lake With Nearby Lakes

Where this data comes from

77 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 WaterMNPCA77 samples · 2020–2025

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 (2)

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