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LakeQuality

Lower Prior Lake vs Mill Pond

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

Lower Prior Lake has a higher water quality grade (B, Good) than Mill Pond (D, Poor). Both are in Scott County, Minnesota.

Lower Prior Lake and Mill Pond are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. Lower Prior Lake (B) is materially cleaner than Mill Pond (D). 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 — Lower Prior 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?

B

Lower Prior Lake

Scott County, Minnesota

Moderate clarity, visible to about 9.5 ft.

D

Mill Pond

Scott County, Minnesota

Murky, only visible to about 6 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.

MetricLower Prior LakeMill Pond
Overall GradeB (Good)D (Poor)
Water Clarity9.5 ft6 ft
Phosphorus26.8 µg/LNo data
Chlorophyll-a (Algae)No dataNo data
Maximum Depth--
Surface Area1.1K acres16 acres
Public AccessUnknownUnknown
Fish Species11
Trophic Statemesotrophiceutrophic

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

Verdict

Lower Prior Lake wins on overall water quality with a Grade B versus Mill Pond's Grade D. Water clarity: 9.5 ft vs 6 ft. For fishing diversity, Lower Prior Lake also leads with 1 species.