Muldrew Lakes Cottagers' Association



Water Quality Tests:


We are very fortunate to have resources from many organizations helping to ensure the continued health of our lake.  Additionally we have several cottagers who participate in water testing activities from May through October and have been doing so for many years.  


The programs Muldrew Lake participates in are as follows:


Lake Partner Program through the Ministry of the Environment and Climate Change

  • Measures total phosphorus and water clarity to help identify early changes to water quality that may be   affected by septic tanks, lawns, fertilizers and climate change among other things

    • Total phosphorus is tested in the early spring

    • Water clarity is tested using  a ‘secchi disc’  every 2 or 3 weeks from spring through early fall
    • Testing has been done for several years  in 3 locations
      • Kerr Island
      • North Lake side of the S curve
      • The ‘big bay’ off Hookery Island


Benthic Monitoring through the Municipality of Muskoka

  • Monitors bottom dwelling aquatic invertebrate communities taken as a measure water health

  • Testing was coordinated in South Muldrew on June 30th and in Patterson’s Bay on August 10th 

  • Many young cottagers participated earning high school volunteer hours


Lake Monitoring Program through the University of Waterloo Faculty of the Environment in partnership with the Muskoka Lakes Association

  • This is the second year Muldrew has participated

  • Also measures clarity and total phosphorus

  • Additional tests for nitrates, nitrites, pH, dissolved oxygen and conductivity

  • 2 U of W students tested at 6 locations around all parts of the lake on July 13th and 23rd

The results of the tests for the 2015 season are below as well as a guide to interpreting Secchi and Total Phosphorus readings.


2015 Guide to Interpreting TP and Secchi Data ...pdf


Lake Partner Program Report Card 2015.pdf


North_Muldrew_Lake_Summary_Report_LPP write up requested.pdf


2016 secchi, TP and calcium results.xlsx 


Benthic 2016 - Patterson's Bay.pdf 


Benthic 2016 - South Muldrew.pdf 




General and Membership Information Email:


Correspondence:  PO Box 659, Gravenhurst ON, P1P 1T9




Information Hot-Line: 705-687-4532


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