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LakeQuality

Island Lake vs Murphy Flowage Lake

Water quality, depth, fish species, and recreation comparison.

Island Lake has a higher water quality grade (B, Good) than Murphy Flowage Lake (C, Fair). Both are in Rusk County, Wisconsin.

Both Island Lake and Murphy Flowage Lake sit in Wisconsin. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. The grades are close: Island Lake (B) and Murphy Flowage Lake (C) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.

With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.

B

Island Lake

Rusk County, Wisconsin

Moderate clarity, visible to about 7.7 ft.

C

Murphy Flowage Lake

Rusk County, Wisconsin

No clarity data.

Side-by-Side Metrics

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

Source: EPA National Aquatic Resource Surveys, 2026.

MetricIsland LakeMurphy Flowage Lake
Overall GradeB (Good)C (Fair)
Water Clarity7.7 ftNo data
Phosphorus15.4 µg/L33.4 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area1.2K acres188 acres
Public AccessUnknownUnknown
Fish Species00
Trophic Statemesotrophiceutrophic

Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).

Verdict

Island Lake wins on overall water quality with a Grade B versus Murphy Flowage Lake's Grade C. For fishing diversity, Island Lake also leads with 0 species.