Madison Lake
Madison Lake in Blue Earth County, Minnesota has a water quality grade of D (Nutrient-rich). 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.
- Clarity
- 4 ft
- Typical in August
- 70°F
- Max depth
- 59 ft
- Area
- 1,447 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- Yes
- Ice-out
- Apr 6
- Open water
- 243 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Madison Lake →
Next lake in Blue Earth County
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. Water quality is graded D based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyAlgae risk
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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4 ft. Phosphorus level: 75 µg/L. Chlorophyll-a: 27.8 µg/L. Trophic State Index: 62.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4 ft | Not graded |
| Phosphorus | 75 µg/L | Poor |
| Chlorophyll-a (Algae) | 27.8 µg/L | Poor |
| Trophic State Index (TSI) | 62 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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 grade measures nutrients and algae, not lodging — cabins and rentals around Madison Lake are listed below.
Top-rated places to stay near Madison Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Madison Lake typically sits around 70°F at the surface in August. 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.
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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 59 ft |
| Surface Area | 1,447 acres |
| Shoreline Length | 12.5 mi |
| Littoral Zone | 50% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Madison Lake (Northwest)Public
- Bray ParkPublic
- Madison Lake (East)Public
Fish Species
Click a species to see every graded 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.
DNR Fisheries Survey Summary
24 surveys on file from MN DNR Fisheries. Most recent: 2023-10-25 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 40.19 | 0.29 lb |
| Black Crappie | 21.69 | 0.24 lb |
| Freshwater Drum | 18.30 | 0.89 lb |
| Yellow Perch | 10.09 | 0.14 lb |
| Largemouth Bass | 9.69 | 1.36 lb |
| Spottail Shiner | 7.90 | — |
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
Black Crappie
Freshwater Drum
Yellow Perch
From the 2023-10-25 survey
A survey targeting age-0 Walleyes was conducted at Madison Lake on 25 October 2023 using 1 hour 43 minutes of standard boat electrofishing. Two age-0 Walleyes were sampled for a catch rate of 1.2/hour on-time. Age-0 Walleye measured 8.5 and 8.7 inches total length. The mean catch rate since 2003 during fry stocked…
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
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.028 m/yr | 5 |
| Phosphorus | ↑ Improving | -35.07 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -5.16 µg/L/yr | 4 |
Ice Season
Historical ice data from Minnesota DNR (125 observations).
Estimated open water season: 243 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 1931-03-04 (1931) | 2018-04-30 (2018) |
| Ice-In | 2018-11-18 (2018) | 2007-01-15 (2007) |
Most recent ice-out: 2026-03-28
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN07-0044-00 · Official waterbody report
County Ranking
Ranked #2 of 5 lakes in Blue Earth County
Nearby Lakes in Blue Earth County
Frequently asked questions about Madison Lake
What is the water quality grade for Madison Lake?
- Madison Lake in Blue Earth County, Minnesota has a water quality grade of D (Nutrient-rich). 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?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Madison Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 27.8 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Madison Lake?
- Madison Lake typically sits around 70°F at the surface in August, 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.
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.
Explore Madison Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded 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 grade
Lakes in the Minnesota River Watershed, ranked by water quality
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Madison Lake
Other Grade D 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)
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