Bass Lake
Lincoln County, WisconsinMesotrophic
Bass Lake earns an A — every scored parameter (clarity and phosphorus) rates among the best monitored waters in Lincoln County. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.
The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. The lake bottoms out at 40 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. At 106 acres, Bass Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Bass Lake ranks 5 of 18 in Lincoln County — solidly in the upper half of the local distribution.
An invasive species record — Chinese Mystery Snail — has been logged at Bass Lake; Wisconsin DNR maintains the official infested-waters list. The fishery is bass-led, with 4 documented species across the lake's records. 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 2025-08-28. Grade methodology: LakeGrade methodology.
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Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 12.5 ft. Phosphorus level: 13.5 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | B |
| Phosphorus | 13.5 µg/L | A |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 40 ft |
| Surface Area | 106 acres |
Fish Species
Click a species to see all Wisconsin and Minnesota lakes where it is found.
→ Best fishing times for Bass Lake (14-day solunar calendar)
→ Is it safe to eat fish from Bass Lake? (mercury & PFAS guide)
→ Bass 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 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.929 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.67 µg/L/yr | 6 |
Location
County Ranking
Ranked #5 of 18 lakes in Lincoln County
Nearby Lakes in Lincoln County
More Wisconsin Lake Rankings
State Parks Near Bass Lake
Other Grade A Lakes in Wisconsin
Washington County · Clarity: 11.8 ft
Washington County · Clarity: 12.6 ft
Walworth County · Clarity: 11 ft
Waukesha County · Clarity: 11.3 ft
Walworth County · Clarity: 20.2 ft
Kenosha County · Clarity: 10 ft
Mesotrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1993. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
EPA Impairment Status
Bass Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10007132 · 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: 2025-08-28
Monitoring stations: 1