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LakeQuality
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Roach Lake

Vilas County, WisconsinLimited DataOligotrophic

On the LakeGrade rubric, Roach Lake pulls an A: clarity at 75.5 ft and phosphorus readings still being added put it in the top bracket for Wisconsin. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

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. A maximum depth of 48 ft puts Roach Lake in the middle of Wisconsin's depth distribution. Roach Lake is small — 48 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Roach Lake ranks 99 of 202 in Vilas County — solidly in the upper half of the local distribution.

Roach Lake has no invasive species recorded in Wisconsin state databases as of 2023, though prevention practices still apply at all access points. The fishery is bass-led, with 2 documented species across the lake's records. 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 2023-08-15. 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 75.5 ft down. Trophic State Index: 15.

MetricValueGrade
Water Clarity (Secchi Depth)75.5 ftA
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)15Oligotrophic

Low nutrients, clear water, excellent for swimming

Lake Details

CharacteristicValue
Maximum Depth48 ft
Surface Area48 acres

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for Roach Lake (14-day solunar calendar)

→ Is it safe to eat fish from Roach Lake? (mercury & PFAS guide)

Roach Lake fishing regulations (limits, seasons, special rules)

Water Quality Trend: Improving

Based on 3 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+1.154 m/yr3
See year-by-year chart →

Location

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County Ranking

Ranked #99 of 202 lakes in Vilas County

Nearby Lakes in Vilas County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2023).

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Common)

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2023-08-15

Monitoring stations: 1