Prairie Lake
Barron County, WisconsinLimited DataEutrophic
Prairie Lake earns an F: phosphorus readings still being added and clarity at 2.0 ft signal heavy nutrient loading from the surrounding watershed.
Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of 16 ft puts Prairie Lake in the middle of Wisconsin's depth distribution. At 1,408 acres, Prairie Lake is one of the larger lakes in Barron County, with partial shoreline records supporting multiple distinct use patterns. Prairie Lake ranks 37 of 37 in Barron County — at the lower end of the locally monitored distribution.
Prairie Lake has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Prairie Lake, one of 5 fish species on record for the lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-24. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2 ft of visibility. Trophic State Index: 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 16 ft |
| Surface Area | 1.4K acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Prairie Lake (14-day solunar calendar)
→ Is it safe to eat fish from Prairie Lake? (mercury & PFAS guide)
→ Prairie Lake fishing regulations (limits, seasons, special rules)
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 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.25 m/yr | 2 |
Location
County Ranking
Ranked #37 of 37 lakes in Barron County
Cleaner Lakes Within 30 Miles
Prairie Lake holds Grade F. 2 nearby lakes hold higher grades.
Nearby Lakes in Barron County
More Wisconsin Lake Rankings
Other Grade F Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Compare Prairie Lake With Nearby Lakes
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1987. 5 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
EPA Impairment Status
Prairie Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10004438 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-09-24
Monitoring stations: 1