Skip to main content
LakeQuality

Roberds Lake vs Union Lake

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

Union Lake has a higher water quality grade (C, Fair) than Roberds Lake (F, Very Poor). Both are in Rice County, Minnesota.

F

Roberds Lake

Rice County, Minnesota

Very murky, less than 2 ft of visibility.

C

Union Lake

Rice County, Minnesota

Very murky, less than 3 ft of visibility.

Side-by-Side Metrics

MetricRoberds LakeUnion Lake
Overall GradeF (Very Poor)C (Fair)
Water Clarity2 ft3 ft
Phosphorus300 µg/L1.4 µg/L
Chlorophyll-a (Algae)No dataNo data
Maximum Depth43 ft10 ft
Surface Area632.29 acres396.74 acres
Public AccessYesYes
Fish Species180
Trophic Statehypereutrophicoligotrophic

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

Verdict

Union Lake wins on overall water quality with a Grade C versus Roberds Lake's Grade F. Water clarity: 3 ft vs 2 ft. For more fish-species variety, Roberds Lake edges ahead with 18 documented species.