Green Lake
Green Lake in Kandiyohi County, Minnesota has a water quality grade of A (Excellent). 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.
- Clarity
- 14.1 ft
- Typical in August
- 69°F
- Max depth
- 110 ft
- Area
- 5,569 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 16
- Open water
- 230 days
Next lake in Kandiyohi County
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). Water quality is graded A based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
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
Water Quality Grade: A (Excellent)
Good clarity, visible to about 14.1 ft. Phosphorus level: 14 µg/L. Chlorophyll-a: 4 µg/L. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.1 ft | Not graded |
| Phosphorus | 14 µg/L | Good |
| Chlorophyll-a (Algae) | 4 µg/L | Good |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay 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
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Planning a trip? Cabins and lodging at Green Lake → · more Minnesota lake trips
Water Temperature
Green Lake typically sits around 69°F at the surface in August. 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.
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 ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 110 ft |
| Average Depth | 21 ft |
| Surface Area | 5,569 acres |
| Shoreline Length | 12 mi |
| Littoral Zone | 37% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Green Lake (East)Public
- Green Lake (Northwest)Public
- Green Lake (Northeast)Public
Fish Species
Click a species to see every graded 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.
DNR Fisheries Survey Summary
44 surveys on file from MN DNR Fisheries. Most recent: 2025-09-12 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 25.46 | 0.12 lb |
| BKS | 17.19 | — |
| Walleye | 11.44 | 1.03 lb |
| Bluntnose Minnow | 8.57 | — |
| Yellow Perch | 5.36 | 0.12 lb |
| Rock Bass | 5.28 | 0.38 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
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
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.044 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.69 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +0.13 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (300 observations).
Estimated open water season: 230 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2024-03-15 (2024) | 2013-05-08 (2013) |
| Ice-In | 1932-11-17 (1932) | 2024-01-04 (2024) |
Most recent ice-out: 2025-03-31
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN34-0079-00 · Official waterbody report
County Ranking
Ranked #4 of 25 lakes in Kandiyohi County
Nearby Lakes in Kandiyohi County
Frequently asked questions about Green Lake
What is the water quality grade for Green Lake?
- Green Lake in Kandiyohi County, Minnesota has a water quality grade of A (Excellent). 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?
- Excellent for swimming, crystal clear water with minimal algae. Green Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 4 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Green Lake?
- Green Lake typically sits around 69°F at the surface in August, 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.
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.
Explore Green Lake across LakeGrade
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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)
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