Mud Lake
Polk County, Wisconsin14 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Mud Lake. Here is what has been measured.
- Eutrophic
- 15 ft max depth
- Limited data
Mud Lake in Polk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.3 ft visibility. Phosphorus: 24.7 µg/L. Maximum depth: 15 ft. Surface area: 14 acres.
Wisconsin DNR lists Largemouth Bass as present on Mud Lake. DNR survey details →
Mud Lake is a 14-acre productive, nutrient-rich eutrophic lake in Polk County, Wisconsin with a maximum depth of 15 feet. Overall water quality is improving over recent sampling years. The lake supports 1 documented fish species including Largemouth Bass. Compared to the 54 other monitored lakes in Polk County, Mud Lake ranks #7 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-09-09. Methodology: how these readings are compared.
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. Check local advisories before you swim.
Whether Mud Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Mud Lake
These are the measurements Wisconsin DNR publishes for Mud 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 4.3 ft. Phosphorus 24.7 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 24.7µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mud Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Largemouth Bass as present on Mud Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mud Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2024).
Fish Species (DNR-rated)
Lake Details
Max depth
15 ft
Surface area
14 acres
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Fish Species
Click a species to see every lake where it is documented.
Fishing Mud Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Improving-2.8 µg/L/yr6 years
Nearby Lakes in Polk County
Frequently asked questions about Mud Lake
Where is Mud Lake?
- Mud Lake is a lake in Polk County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Mud Lake?
- Mud Lake in Polk County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 4.3 ft visibility. Phosphorus: 24.7 µg/L. Maximum depth: 15 ft. Surface area: 14 acres.
Is Mud Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Mud Lake?
- Mud Lake has a maximum depth of 15 feet. The lake covers 14 acres.
What fish are in Mud Lake?
- Fish species found in Mud Lake include Largemouth Bass. Mud Lake is located in Polk County, Wisconsin.
What did the DNR fisheries survey find at Mud Lake?
- Wisconsin DNR lists Largemouth Bass as present on Mud Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mud Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Mud Lake across LakeQuality
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Where this data comes from
9 measurements from 1 monitoring station, 2023–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX9 samples · 2023–2024
Analytical methods
- Phosphorus by Colorimetry
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
Fish and recreation data from Wisconsin DNR Lakes