Secchi Depth:

What is it?

A measure of water transparency or clarity. It shows the depth that a black and white (Secchi) disk can be seen from the surface.

​

Water transparency depends on the amount of particles in the water.  These particles can be algae or sediment from erosion, the more particles – the less water transparency.  

 

Relation to Rainfall...

Water transparency is directly related to the amount of Phosphorous and Chlorophyll-a in the lake.  These nutrients enter the lake via the "Inlet" and the shoreline. Looking at correlation between rainfall and water clarity helps us understand how well we are controlling the potential of Phosphorous that can get into the lake!