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LakeQuality

Blue Spring Lake vs Rock Lake

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

Rock Lake has a higher water quality grade (A, Excellent) than Blue Spring Lake (C, Fair). Both are in Jefferson County, Wisconsin.

Both Blue Spring Lake and Rock 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. Rock Lake (A) is materially cleaner than Blue Spring Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.

For a recreational visitor, the wider grade gap is decisive — Rock Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?

C

Blue Spring Lake

Jefferson County, Wisconsin

Murky, only visible to about 6 ft.

A

Rock Lake

Jefferson County, Wisconsin

Good clarity, visible to about 12.5 ft.

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.

MetricBlue Spring LakeRock Lake
Overall GradeC (Fair)A (Excellent)
Water Clarity6 ft12.5 ft
Phosphorus23.8 µg/L17.9 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area136 acres1.4K acres
Public AccessUnknownUnknown
Fish Species00
Trophic Stateeutrophicmesotrophic

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

Verdict

Rock Lake wins on overall water quality with a Grade A versus Blue Spring Lake's Grade C. Water clarity: 12.5 ft vs 6 ft. For fishing diversity, Rock Lake also leads with 0 species.