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LakeQuality

Big Portage (W Bay Lake in Cass County, Minnesota has nutrient and algae measurements on record from state and federal monitoring. A water-quality reading is not a swimming clearance. The state water agency and county health departments post current advisories; check them before you swim.. Water clarity: 8.5 ft visibility. Phosphorus: 18.5 µg/L. Chlorophyll-a (algae): 5.6 µg/L. Always check local health department advisories before swimming.

Key Metrics

MetricValue
Water Clarity (Secchi Depth)8.5 ft
Phosphorus18.5 μg/L
Chlorophyll-a (Algae)5.6 μg/L
Maximum Depth23 ft
LocationCass County, Minnesota

How does Big Portage (W Bay Lake compare?

With an overall water-quality readings of , Big Portage (W Bay Lake matches or beats the Minnesota state average. It ranks #60 of 104 lakes in Cass County by water quality score.

Water clarity (Secchi depth) sits at 8.5 feet. That puts the lake in good clarity range, with limited algae interference. Algae levels (chlorophyll-a) measure 5.6 µg/L — low and well within safe swimming guidelines.

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