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Green Lake

Kandiyohi County, MinnesotaMesotrophic

On the LakeGrade rubric, Green Lake pulls an A: clarity at 13.1 ft and 14 µg/L of phosphorus put it in the top bracket for Minnesota. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. At 110 ft of maximum depth, Green Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 5,569 acres, Green Lake is one of the larger lakes in Kandiyohi County, with 12.0 miles of shoreline supporting multiple distinct use patterns. Within Kandiyohi County's 35 graded waters, Green Lake sits at rank 3, near the top of the local distribution.

Zebra mussel presence at Green Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Green Lake's fishery is anchored by muskellunge, with 22 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Green Lake more than two dozen times, putting the median around Apr 16 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-12. Grade methodology: LakeGrade methodology.

Reviewed by LakeQuality Editorial Team · Updated

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Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Good clarity, visible to about 13.1 ft. Phosphorus level: 14 µg/L. Trophic State Index: 41.

MetricValueGrade
Water Clarity (Secchi Depth)13.1 ftB
Phosphorus14 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)41Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth110 ft
Average Depth21 ft
Surface Area5.6K acres
Shoreline Length12 mi
Littoral Zone37%
Public AccessYes

Fish Species

bigmouth buffalo,black bullhead,black crappie,bluegill,bowfin (dogfish),brown bullhead,channel catfish,common carp,green sunfish,hybrid sunfish,largemouth bass,muskellunge,northern pike,orangespotted sunfish,pumpkinseed,rock bass,smallmouth bass,tullibee (cisco),walleye,white sucker,yellow bullhead,yellow perch

Click a species to see all Minnesota and Wisconsin lakes where it is found.

→ Best fishing times for Green Lake (14-day solunar calendar)

→ Is it safe to eat fish from Green Lake? (mercury & PFAS guide)

Green Lake fishing regulations (limits, seasons, special rules)

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 watermilfoilzebra mussel

Water Quality Trend: Declining

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.269 m/yr5
Phosphorus Declining+1.1 µg/L/yr5
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (300 observations).

Typical Ice-Out
Apr 16
Typical Ice-In
Dec 2

Estimated open water season: 230 days

EarliestLatest
Ice-Out2024-03-15 (2024)2013-05-08 (2013)
Ice-In1932-11-17 (1932)2024-01-04 (2024)

Most recent ice-out: 2025-03-31

Location

Loading map…

County Ranking

Ranked #3 of 35 lakes in Kandiyohi County

Nearby Lakes in Kandiyohi County

DNR Fisheries Survey Summary

44 surveys on file from MN DNR Fisheries. Most recent: 2025-09-12 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill25.460.12 lb
BKS17.19
Walleye11.441.03 lb
Bluntnose Minnow8.57
Yellow Perch5.360.12 lb
Rock Bass5.280.38 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

425 fish · 29 in · 2025-09-12
133670trophy 1023456789

Walleye

311 fish · 526 in · 2025-09-12
64320trophy 2468101214161820222426

Yellow Perch

47 fish · 58 in · 2025-09-12
311605678

Rock Bass

166 fish · 311 in · 2025-09-12
4221034567891011

From the 2025-09-12 survey

A standard survey in Green Lake was conducted during mid-September of 2025 using lake survey gillnets and trapnets. Standard surveys were done during the last week of July or first week of August prior to 2021. Targeted surveys were conducted to determine if September gillnetting would more effectively sample the…

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 Green Lake. 3 reports on file.

Reservoir Info (USACE NID)

Green Lake is a man-made reservoir impounded by the Green Lake (completed 1938), built primarily for recreation on the CROW RIVER MIDDLE FORK; gravity-type dam, 9 ft tall and 62 ft long.

Surface area
5,560 ac
Normal storage
11,000 ac-ft
Max storage
11,700 ac-ft
Drainage area
149 sq mi
Hazard class
Low
Owner
MNDNR-Wildlife

Source: USACE National Inventory of Dams, NID ID MN00370 · Operator website

EPA Impairment Status

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

Causes of impairment

MercurySalinity / chlorides

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

Source: EPA ATTAINS assessment unit MN34-0079-00 · Official waterbody report

Data Sources

Water quality data from the EPA Water Quality Portal

Impairment status from EPA ATTAINS 303(d) database

Grading methodology based on Metropolitan Council standards

Lake details from Minnesota DNR LakeFinder

Ice data from Minnesota DNR Climate

Most recent sample: 2024-09-12

Monitoring stations: 1