Is South Branch Lake safe to swim in?

Good for swimming, clear water with low algae levels. South Branch Lake has an overall water quality grade of B. Always check local health department advisories before swimming.

Algoma District County, Ontario · Water Quality Report Card

South Branch Lake

Grade B — Good

Oligotrophic

South Branch Lake in Algoma District, Ontario received a water quality grade of B (Good). Water clarity: 2.7 m visibility. Phosphorus: 7.1 µg/L.

Clarity: 2.7 m
Type: Oligotrophic

Where to stay →Safe to swim?

South Branch Lake is a cold, clear oligotrophic lake in Algoma District County, Ontario. Water quality is graded B based on 2 sampling years through 2025. Compared to the 217 other monitored lakes in Algoma District County, South Branch Lake ranks #186 for water quality.

Source: EPA Water Quality Portal sampling records, Ontario MECP, last sampled 2025-08-01. Grade methodology: LakeGrade methodology.

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Swimming Safety

Good for swimming, clear water with low algae levels

Water Quality Grade: B, Good

Moderate clarity, visible to about 8.9 ft. Phosphorus level: 7.1 µg/L. Trophic State Index: 39.

Metric	Value	Grade
Water Clarity (Secchi Depth)	2.73 m	C
Phosphorus	7.1 µg/L	A
Chlorophyll-a (Algae)	No data
Trophic State Index (TSI)	39	Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near South Branch Lake

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