Green Lake
Kandiyohi County, Minnesota5,569 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Green Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 2 aquatic invasives
- 110 ft max depth
- Public access
Green Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14.1 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 110 ft. Surface area: 5569.01 acres.
Minnesota DNR's Standard Survey on September 12, 2025 caught 12.17 walleye per gill net at Green Lake. Length samples in the latest survey that recorded them ran 5–26 inches. DNR survey details →
Free interactive depth-contour map of Green Lake, reaching a maximum surveyed depth of 110 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Green Lake is a 5,569-acre mesotrophic lake in Kandiyohi County, Minnesota with a maximum depth of 110 feet (21-foot average). Overall water quality is declining over recent sampling years. The lake supports 22 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 3 public boat landings. Compared to the 24 other monitored lakes in Kandiyohi County, Green Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-25. Methodology: how these readings are compared.
At about 5,600 acres, Green Lake is large enough that where you stay decides which shore you see most of. It has 3 public boat landings, so a lakefront rental is not the only way to get a boat on the water. The median ice-out date is April 16, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Green Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Green Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.1 ft of visibility
- Boat launch3 documented ramps
- Fishing22 species recorded
- Ice seasonIce-out around Apr 16
- Deep water110 ft surveyed max depth
- Big water5,569 acres
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Green Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, salinity / chlorides. Check local advisories before you swim.
Whether Green Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Green Lake
These are the measurements Minnesota PCA publishes for Green Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14.1 ft. Phosphorus 14 µg/L. Chlorophyll-a 4 µg/L. TSI 42.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 14µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 42 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Green Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Green Lake typically sits around 68°F at the surface in September. Summer average is about 68°F. Usually warmest in Jul (about 70°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (70°F).
Typical surface water temperature by month, from 301 field readings (2016–2025) via the EPA Water Quality Portal. See the full Green Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Green Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (7,656 cells/mL) on November 22, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on September 12, 2025 caught 12.17 walleye per gill net at Green Lake. Length samples in the latest survey that recorded them ran 5–26 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Green Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
44 surveys on file from MN DNR Fisheries. Most recent: 2025-09-12 (Standard Survey).
44 surveys on file · most recent 2025-09-12 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 25.46 | 2–9 in 2025-09-12 | 0.12 lb |
| Walleye | 11.44 | 5–26 in 2025-09-12 | 1.03 lb |
| Bluntnose Minnow | 8.57 | ||
| Yellow Perch | 5.36 | 5–8 in 2025-09-12 | 0.12 lb |
| Rock Bass | 5.28 | 3–11 in 2025-09-12 | 0.38 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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
Walleye
Yellow Perch
Rock Bass
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…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Green Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GreenFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — GreenFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — GreenPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
110 ft
Average depth
21 ft
Surface area
5,569 acres
Shoreline
12 mi
Littoral zone
37%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
152 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,145 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Green Lake (East)Public
- Green Lake (Northwest)Public
- Green Lake (Northeast)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Green Lake
Compare lakeside cabins, hotels, and vacation rentals near Green Lake in Kandiyohi 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 Green Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 trip? Cabins and lodging at Green Lake → · more Minnesota lake trips
Follow Green Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Green 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.
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.69 µg/L/yr6 years
Chlorophyll-a
Worsening+0.13 µg/L/yr6 years
Ice season
Typical ice-out
Apr 16
Earliest Mar 15, 2024 · Latest May 8, 2013
Typical ice-in
Dec 2
Earliest Nov 17, 1932 · Latest Jan 4, 2024
Most recent ice-out
Mar 31
2025
300 observations · Minnesota PCA ice records
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
Designated uses not supporting: Cultural, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN34-0079-00 · Official waterbody report
Nearby Lakes in Kandiyohi County
Frequently asked questions about Green Lake
Where is Green Lake?
- Green Lake is a lake in Kandiyohi County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Green Lake?
- Green Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 14.1 ft visibility. Phosphorus: 14 µg/L. Chlorophyll-a (algae): 4 µg/L. Maximum depth: 110 ft. Surface area: 5569.01 acres.
Is Green Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Green Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, salinity / chlorides. Check local advisories before you swim.
What is the water temperature of Green Lake?
- Green Lake typically sits around 68°F at the surface in September, from 301 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Green Lake?
- Green Lake has a maximum depth of 110 feet and an average depth of 21 feet. The lake covers 5569.01 acres.
What fish are in Green Lake?
- Fish species found in Green Lake include 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. Green Lake is located in Kandiyohi County, Minnesota.
What did the DNR fisheries survey find at Green Lake?
- Minnesota DNR's Standard Survey on September 12, 2025 caught 12.17 walleye per gill net at Green Lake. Length samples in the latest survey that recorded them ran 5–26 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Green Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Green Lake thaw?
- Green Lake typically has ice-out around Apr 16. Ice typically forms around Dec 2. The open water season is approximately 230 days.
Does Green Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Green Lake (clouds, ice, or an off-season gap). The most recent reading was low (7,656 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Green Lake?
- Green Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Green Lake (East), Green Lake (Northwest), Green Lake (Northeast). Public access is listed as yes.
Can I fish at Green Lake?
- Green Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Green Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Kandiyohi County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Crow River Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Green Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Green Lake With Nearby Lakes
Where this data comes from
94 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA94 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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