Marion Lake
Dakota County, Minnesota530 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Marion Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Mercury
- 2 aquatic invasives
- 21 ft max depth
- Public access
- Limited data
Marion Lake in Dakota County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 7 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Maximum depth: 21 ft. Surface area: 530.3 acres.
Minnesota DNR's Targeted Survey on July 12, 2021 caught 0.50 walleye per gill net at Marion Lake. DNR survey details →
Marion Lake is a 530-acre mesotrophic lake in Dakota County, Minnesota with a maximum depth of 21 feet. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 44 other monitored lakes in Dakota County, Marion Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Methodology: how these readings are compared.
Marion Lake covers about 530 acres in Dakota County. It has one public boat landing. The median ice-out date is March 30, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Marion Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Marion Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing14 species recorded
- Ice seasonIce-out around Mar 30
Swimming conditions
Readings onlyLimited data
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. 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.
Moderate clarity, visible to about 7 ft. Phosphorus 20 µg/L. Chlorophyll-a 4.6 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.6µg/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. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Marion Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Marion Lake typically sits around 56°F at the surface in October. Summer average is about 76°F. Usually warmest in Jul (about 81°F) and coldest in Feb (about 38°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (38°F) to its warmest (81°F).
Typical surface water temperature by month, from 169 field readings (2010–2025) via the EPA Water Quality Portal. See the full Marion Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on July 12, 2021 caught 0.50 walleye per gill net at Marion Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2021-07-12 (Targeted Survey).
12 surveys on file · most recent 2021-07-12 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 36.09 | 3–6 in 2021-07-12 | 0.12 lb |
| Black Crappie | 14.73 | 6–8 in 2021-07-12 | 0.16 lb |
| Black Bullhead | 9.31 | 12–13 in 2011-05-16 | 0.7 lb |
| Yellow Perch | 7.83 | 5–8 in 2021-07-12 | 0.14 lb |
| Yellow Bullhead | 6.94 | 7–10 in 2021-07-12 | 0.67 lb |
| Largemouth Bass | 6.44 | 11–16 in 2021-07-12 | 1.23 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
Black Crappie
Black Bullhead
Yellow Perch
From the 2021-07-12 survey
Lake Marion is a 530 acre class 35 lake in western Dakota County. Lake Marion is primarily managed for Walleye, and secondarily for Largemouth Bass, Northern Pike, and Bluegill. The City of Lakeville owns and maintains two park areas in the lake - Antler's Park on the SE corner and Casperson Park on the west side of…
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
21 ft
Surface area
530 acres
Shoreline
10.2 mi
Littoral zone
86%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
9 sq mi
HydroLAKES / HydroSHEDS
Elevation
974 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Marion LakePublic
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 Dakota 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 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
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: Stable
Based on 4 years of monitoring (2021–2025).
Water clarity
Stable4 years
Ice season
Typical ice-out
Mar 30
Earliest Mar 3, 2024 · Latest May 1, 2018
Most recent ice-out
Mar 28
2026
16 observations · Minnesota PCA ice records
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.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN19-0026-01 · Official waterbody report
Nearby Lakes in Dakota County
Frequently asked questions about Marion Lake
Where is Marion Lake?
- Marion Lake is a lake in Dakota 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 Dakota County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 7 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Maximum depth: 21 ft. Surface area: 530.3 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. Check local advisories before you swim.
What is the water temperature of Marion Lake?
- Marion Lake typically sits around 56°F at the surface in October, from 169 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Marion Lake?
- Marion Lake has a maximum depth of 21 feet. The lake covers 530.3 acres.
What fish are in Marion Lake?
- Fish species found in Marion Lake include black bullhead, black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Marion Lake is located in Dakota County, Minnesota.
What did the DNR fisheries survey find at Marion Lake?
- Minnesota DNR's Targeted Survey on July 12, 2021 caught 0.50 walleye per gill net at Marion Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Marion Lake’s water-quality measurements separately, and the water-quality trend over 4 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
When does Marion Lake thaw?
- Marion Lake typically has ice-out around Mar 30.
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. 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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Species activity outlook by water temperature and season
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Where this data comes from
58 measurements from 1 monitoring station, 2021–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA58 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Analysis of Chlorophyll in Periphyton and Plankton
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