Simcoe County Lake Quality

Ontario, 18 lakes, average grade B (Good)

There are 18 graded lakes in Simcoe County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. With an average grade of B, Simcoe County sits comfortably above the Ontario median.

Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Gloucester Pool (A) is the cleanest in the county.

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Quick Answers for Simcoe County

Cleanest lakes in Simcoe County →Cleanest lakes in Ontario →Safest swimming lakes in Ontario →

Planning a trip? Check special fishing regulations for Gloucester Pool — or check the official Ontario fishing regulations.

All Lakes in Simcoe County

Rank	Lake	Grade	Clarity	Phosphorus
1	Gloucester Pool	A	15.4 ft	9.6 µg/L
2	St George Lake	A	-	17.3 µg/L
3	Couchiching Lake	A	22 ft	6.9 µg/L
4	Lake Simcoe	A	31.5 ft	7.1 µg/L
5	Couchiching Lake	A	13.1 ft	10.3 µg/L
6	Little Lake	A	11.5 ft	9.7 µg/L
7	Simcoe Lake	A	14.8 ft	10.6 µg/L
8	Sparrow Lake	A	14.8 ft	10.9 µg/L
9	Bass Lake	B	9.8 ft	10.9 µg/L
10	Farlain Lake	B	9.2 ft	9.9 µg/L
11	Little Lake	B	10.5 ft	-
12	Orr Lake	B	8.2 ft	12.6 µg/L
13	Little Lake	B	8.5 ft	9.4 µg/L
14	Long Lake	B	9.4 ft	8.8 µg/L
15	St John Lake	B	8.2 ft	29.4 µg/L
16	Tea Lake	B	4.8 ft	15.2 µg/L
17	Little Lake	C	5.9 ft	20.5 µg/L
18	Maclean Lake	D	4.1 ft	-