Save Lake Weir Board maintains a lake watch committee to conduct regular, systematic lake water testing in Lake Weir. Thanks to the members that volunteered to assist with this effort.  The program summary is as follows:

  • Samples are collected monthly
  • Treated as 3 bodies of water (big lake, sunset harbor, little lake)
  • 3 samples across each body of water per month at the exact geometric location
  • The assigned group takes measurements for each of the bodies- consistently – same time, same day, same person, for each body of water

Metrics covered:

  • total ni
  • total ph
  • chlorophyll
  • water clarity
  • true color
  • connectivity

To learn more about the Lake Watch Program, click here. 

The most current data was compiled early 2024 and presented at the annual meeting.  The full report for all three collection points is under the links below.  The following charts are from the Big Lake Weir data:



Summary From 1990 to 2024:  

Phosphorus – 70% Increase        Nitrogen – 13% Increase        Chlorophyll – 70% Increase        Clarity – 42% Decrease

Lake Weir Water Levels compared to Annual Rainfall

*Source: St. Johns Water Management District

Lake Weir  – Then and Now                                                                                                                          



Important Studies and Data