Marion Lake
McLeod County, Minnesota520 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Marion Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
- 15 ft max depth
- Public access
- Limited data
Marion Lake in McLeod County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Phosphorus: 71 µg/L. Chlorophyll-a (algae): 73 µg/L. Maximum depth: 15.2 ft. Surface area: 520.43 acres.
Minnesota DNR's Targeted Survey on July 28, 2025 caught 22.89 walleye per gill net at Marion Lake. Length samples in the latest survey that recorded them ran 6–14 inches. DNR survey details →
Marion Lake is a 520-acre productive, nutrient-rich eutrophic lake in McLeod County, Minnesota with a maximum depth of 15 feet (10-foot average). The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 4 other monitored lakes in McLeod County, Marion Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-09-19. Methodology: how these readings are compared.
What Marion Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing13 species recorded
Swimming conditions
Readings onlyRecreation use not supported
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. Marion Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Marion 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 Marion Lake
These are the measurements Minnesota PCA publishes for Marion Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 71 µg/L. Chlorophyll-a 73 µg/L. TSI 69.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 71µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 73µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 69 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Marion Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Marion Lake typically sits around 72°F at the surface in September. Summer average is about 76°F. Usually warmest in Aug (about 82°F) and coldest in Jun (about 69°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (69°F) to its warmest (82°F).
Typical surface water temperature by month, from 12 field readings (2016–2021) via the EPA Water Quality Portal. See the full Marion Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Marion Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was very high (1,169,499 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Targeted Survey on July 28, 2025 caught 22.89 walleye per gill net at Marion Lake. Length samples in the latest survey that recorded them ran 6–14 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
26 surveys on file from MN DNR Fisheries. Most recent: 2025-09-10 (Targeted Survey).
26 surveys on file · most recent 2025-09-10 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Yellow Perch | 40.19 | 5–11 in 2025-07-28 | 0.16 lb |
| Walleye | 33.81 | 6–14 in 2025-09-10 | 1.32 lb |
| Black Crappie | 31.22 | 2–14 in 2025-07-28 | 0.26 lb |
| Black Bullhead | 28.46 | 5–21 in 2025-07-28 | 0.88 lb |
| Largemouth Bass | 20.67 | 11 in 2025-07-28 | 0.99 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.
Yellow Perch
Walleye
Black Crappie
Black Bullhead
From the 2025-09-10 survey
A targeted survey (fall nighttime electrofishing) was conducted on Marion Lake on September 10th, 2025, to evaluate young of the year (YOY) and yearling Walleye abundance. A total of 101 YOY were sampled for a catch rate of 101.0 fish/hr., which was above the lake's historical (1994 to 2025) median (30.0 fish/hr.).…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Marion Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MarionFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — MarionFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MarionPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
15.2 ft
Average depth
10 ft
Surface area
520 acres
Shoreline
6.7 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
15 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,020 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Marion Lake (East)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 Marion Lake
Compare lakeside cabins, hotels, and vacation rentals near Marion Lake in McLeod 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Marion Lake are listed below.
Top-rated places to stay near Marion 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 whole trip? See where to stay at Minnesota’s top lakes →
Follow Marion Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Marion Lake
Reservoir Info (USACE NID)
Marion Lake is a man-made reservoir impounded by the Lake Marion (completed 1948), built primarily for other on the Buffalo Creek-TR; other-type dam, 10 ft tall and 37 ft long.
- Surface area
- 520 ac
- Normal storage
- 173 ac-ft
- Max storage
- 404 ac-ft
- Drainage area
- 7.4 sq mi
- Hazard class
- Low
- Owner
- McLeod County Sportsman's Club
Source: USACE National Inventory of Dams, NID ID MN00156 · Operator website
EPA Impairment Status
Marion Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN43-0084-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Marion Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Brownton WwtpBrownton · 4.2 mi away · NPDES MN0022951Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in McLeod County
Frequently asked questions about Marion Lake
Where is Marion Lake?
- Marion Lake is a lake in McLeod County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Marion Lake?
- Marion Lake in McLeod County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Phosphorus: 71 µg/L. Chlorophyll-a (algae): 73 µg/L. Maximum depth: 15.2 ft. Surface area: 520.43 acres.
Is Marion Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Marion Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Marion Lake?
- Marion Lake typically sits around 72°F at the surface in September, from 12 EPA Water Quality Portal field readings (2016–2021). That is a typical value for the month, not a live reading.
How deep is Marion Lake?
- Marion Lake has a maximum depth of 15.2 feet and an average depth of 10 feet. The lake covers 520.43 acres.
What fish are in Marion Lake?
- Fish species found in Marion Lake include black bullhead, black crappie, bluegill, brown bullhead, channel catfish, common carp, hybrid sunfish, largemouth bass, northern pike, sunfish, walleye, yellow bullhead, yellow perch. Marion Lake is located in McLeod County, Minnesota.
What did the DNR fisheries survey find at Marion Lake?
- Minnesota DNR's Targeted Survey on July 28, 2025 caught 22.89 walleye per gill net at Marion Lake. Length samples in the latest survey that recorded them ran 6–14 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
Does Marion Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Marion Lake (clouds, ice, or an off-season gap). The most recent reading was very high (1,169,499 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Marion Lake?
- Marion Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Marion Lake (East). Public access is listed as yes.
Can I fish at Marion Lake?
- Marion Lake has 1 documented boat landing 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 Marion Lake across LakeQuality
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Where this data comes from
10 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 Water
MNPCA10 samples · 2021
Analytical methods
- 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory