Madison Lake
Blue Earth County, Minnesota1,447 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Madison Lake. Here is what has been measured.
- Eutrophic
- Impaired · Impaired biota (cause unknown)
- Eurasian watermilfoil
- 59 ft max depth
- Public access
Madison Lake in Blue Earth County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4 ft visibility. Phosphorus: 75 µg/L. Chlorophyll-a (algae): 27.8 µg/L. Maximum depth: 59 ft. Surface area: 1447.14 acres.
Minnesota DNR's Targeted Survey on August 22, 2025 caught 2.53 largemouth bass per hour of electrofishing at Madison Lake. Length samples in the latest survey that recorded them ran 3–19 inches. DNR survey details →
Free interactive depth-contour map of Madison Lake, reaching a maximum surveyed depth of 50 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Madison Lake is a 1,447-acre productive, nutrient-rich eutrophic lake in Blue Earth County, Minnesota with a maximum depth of 59 feet. Overall water quality is improving over recent sampling years. The lake supports 20 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 3 public boat landings. Compared to the 4 other monitored lakes in Blue Earth County, Madison Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-21. Methodology: how these readings are compared.
Madison Lake covers about 1,400 acres in Blue Earth County. 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 6, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Madison Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Madison Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
- Fishing20 species recorded
- Ice seasonIce-out around Apr 6
- Deep water59 ft surveyed max depth
- Big water1,447 acres
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. Madison Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Madison 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 Madison Lake
These are the measurements Minnesota PCA publishes for Madison Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 4 ft. Phosphorus 75 µg/L. Chlorophyll-a 27.8 µg/L. TSI 62.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 75µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 27.8µg/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. | 62 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Madison Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Madison Lake typically sits around 58°F at the surface in October. Summer average is about 68°F. Usually warmest in Jul (about 70°F) and coldest in Apr (about 44°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (44°F) to its warmest (70°F).
Typical surface water temperature by month, from 1,191 field readings (2010–2025) via the EPA Water Quality Portal. See the full Madison Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on August 22, 2025 caught 2.53 largemouth bass per hour of electrofishing at Madison Lake. Length samples in the latest survey that recorded them ran 3–19 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Madison Lake’s water-quality measurements separately, and the water-quality trend over 5 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
27 surveys on file from MN DNR Fisheries. Most recent: 2025-10-30 (Targeted Survey).
27 surveys on file · most recent 2025-10-30 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 48.60 | 3–8 in 2025-07-18 | 0.29 lb |
| Black Crappie | 20.61 | 3–12 in 2025-07-18 | 0.25 lb |
| Bluntnose Minnow | 20.50 | ||
| Freshwater Drum | 18.17 | 7–20 in 2025-07-18 | 0.91 lb |
| Largemouth Bass | 9.96 | 3–19 in 2025-07-18 | 1.37 lb |
| Yellow Perch | 9.79 | 5–10 in 2025-07-18 | 0.14 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
Freshwater Drum
Largemouth Bass
From the 2025-10-30 survey
A survey targeting age-0 Walleyes was conducted at Madison Lake on 30 October 2025 using 90 minutes of standard boat electrofishing. No age-0 Walleyes were sampled for a catch rate of 0.0/hour on-time for the second year in a row. The mean catch rate since 2003 during fry stocked years (n=11) was 31.8/per hour on-time…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Madison Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MadisonFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — MadisonFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — MadisonPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
59 ft
Surface area
1,447 acres
Shoreline
12.5 mi
Littoral zone
50%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
8 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,007 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Madison Lake (Northwest)Public
- Bray ParkPublic
- Madison 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 Madison Lake
Compare lakeside cabins, hotels, and vacation rentals near Madison Lake in Blue Earth 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 Madison Lake are listed below.
Top-rated places to stay near Madison 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 Madison Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Madison 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: Improving
Based on 5 years of monitoring (2021–2025).
Water clarity
Improving5 years
Phosphorus
Improving-35.07 µg/L/yr4 years
Chlorophyll-a
Improving-5.16 µg/L/yr4 years
Ice season
Typical ice-out
Apr 6
Earliest Mar 4, 1931 · Latest Apr 30, 2018
Typical ice-in
Dec 5
Earliest Nov 18, 2018 · Latest Jan 15, 2007
Most recent ice-out
Mar 28
2026
125 observations · Minnesota PCA ice records
EPA Impairment Status
Madison 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: Aquatic life, Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN07-0044-00 · Official waterbody report
Nearby Lakes in Blue Earth County
Frequently asked questions about Madison Lake
Where is Madison Lake?
- Madison Lake is a lake in Blue Earth County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Madison Lake?
- Madison Lake in Blue Earth County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 4 ft visibility. Phosphorus: 75 µg/L. Chlorophyll-a (algae): 27.8 µg/L. Maximum depth: 59 ft. Surface area: 1447.14 acres.
Is Madison Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Madison Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Madison Lake?
- Madison Lake typically sits around 58°F at the surface in October, from 1,191 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Madison Lake?
- Madison Lake has a maximum depth of 59 feet. The lake covers 1447.14 acres.
What fish are in Madison Lake?
- Fish species found in Madison Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, bowfin (dogfish), channel catfish, common carp, freshwater drum, gizzard shad, largemouth bass, northern pike, quillback, river carpsucker, shortnose gar, walleye, white bass, white crappie, white sucker, yellow bullhead, yellow perch. Madison Lake is located in Blue Earth County, Minnesota.
What did the DNR fisheries survey find at Madison Lake?
- Minnesota DNR's Targeted Survey on August 22, 2025 caught 2.53 largemouth bass per hour of electrofishing at Madison Lake. Length samples in the latest survey that recorded them ran 3–19 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Madison Lake’s water-quality measurements separately, and the water-quality trend over 5 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Madison Lake thaw?
- Madison Lake typically has ice-out around Apr 6. Ice typically forms around Dec 5. The open water season is approximately 243 days.
Are there boat ramps on Madison Lake?
- Madison Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Madison Lake (Northwest), Bray Park, Madison Lake (East). Public access is listed as yes.
Can I fish at Madison Lake?
- Madison 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 Madison Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Blue Earth County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Minnesota River Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Madison Lake
Other Lakes in Minnesota
Eutrophic Lakes in Minnesota
Compare Madison Lake With Nearby Lakes
Where this data comes from
107 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
MNPCA107 samples · 2021–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by 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