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LakeQuality
A

Lower Sugarbush Lake

Vilas County, WisconsinOligotrophic

Lower Sugarbush Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Vilas County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 202 graded lakes in Vilas County, Lower Sugarbush Lake sits at rank 84, above the county median.

Lower Sugarbush Lake has no invasive species recorded in Wisconsin state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Lower Sugarbush Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-09-02. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 45.9 ft down. Phosphorus level: 10.3 µg/L. Trophic State Index: 30.

MetricValueGrade
Water Clarity (Secchi Depth)45.9 ftA
Phosphorus10.3 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)30Oligotrophic

Low nutrients, clear water, excellent for swimming

Water Quality Trend: Declining

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.329 m/yr6
Phosphorus Declining+0.68 µg/L/yr4
See year-by-year chart →

Location

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County Ranking

Ranked #84 of 202 lakes in Vilas County

Nearby Lakes in Vilas County

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2024-09-02

Monitoring stations: 2