Inland Water Quality Reports
The Township of Georgian Bay’s Inland Water Quality reports:
- 2023 Report: https://sixmilelake.net/pub/water/WQ_2023_Report.pdf
- 2021 Report: https://sixmilelake.net/pub/water/WQ_2021_Report.pdf
- 2019 Report: https://sixmilelake.net/pub/water/WQ_2019_Report.pdf
- 2018 Report: https://sixmilelake.net/pub/water/WQ_2018_Report.pdf
- 2017 Report: https://sixmilelake.net/pub/water/WQ_2017_Report.pdf:
- 2016 Report::https://sixmilelake.net/pub/water/WQ_2016_Report.pdf
- 2015 Report: https://sixmilelake.net/pub/water/WQ%202015%20Inland%20Report.pdf
- 2014 Report::https://sixmilelake.net/pub/water/WQ%202014%20Inland%20Report.pdf
- 2013 Report: https://sixmilelake.net/pub/water/WQ%202013%20Inland%20Report.pdf
- 2012 Report: https://sixmilelake.net/pub/water/WQ%202012%20Inland%20Report.pdf
Muskoka Watershed Reports
- 2023-4 Algae Monitoring Program: https://sixmilelake.net/pub/water/2024_AlgaeMonitoringProgram.pdf
Love Your Lake
- 2024 Love Your Lake Summary Report: https://sixmilelake.net/pub/water/2024_LRL_Report.pdf
Lake Partner Program
The Lake Partner Program is a province-wide, volunteer-based, water-quality monitoring program. The Six Mile Lake Cottagers Association has been an active participant in this program since 1996.
Two water samples are collected in late May each year. These samples are sent to the Lake Environmental Science Center laboratory in Dorset, Ontario where they are tested for phosphorous content.
From early May until mid October, water clarity readings and lake temperature readings are taken every 2 to 3 weeks.

Secchi Disc
The clarity readings are taken using a Secchi disc which is a black and white metal disc about 8 inches in diameter. It is lowered into the water at the same location on the lake each time (in our case, just west of Cedar Nook) and the depth in metres that it is no longer visible is recorded.
These clarity and temperature readings are sent to Dorset at the end of October each year.
In the spring of the following year, a report is published showing all the data recorded for all the target lakes and locations in Ontario. You can see the province wide report at the Lake Partner web site.
The 20 years of water quality data presented at the 2010 Annual General Meeting is available below.
20 Year Water Quality Report.pdf
Interpreting Secchi Disc Results
| Secchi Reading in metres | Lake Nutrient Status |
|---|---|
| Over 5 metres | Oligotrophic, there are few nutrients in the water. |
| 3.0-4.9 metres | Mesotrophic, the water is moderately enriched. |
| Less than 2.9 metres | Eutrophic, the water is enriched with high levels of nutrients |
Six Mile Lake has been averaging around 5.0 metres for more than 10 years.
Water Quality Data

Water Quality Data