Average Secchi Disk Transparency
Average Secchi Disk Transparency
Average Secchi Disk Transparency
Meter (meters)
WQ1: The annual average deep water transparency as measured by Secchi disk shall not be decreased below 29.7 meters (97.4 feet), the average levels recorded between 1967 and 1971 by the University of California, Davis.
This Indicator is reported in the following LT Info areas:
Average Secchi Disk Transparency
By: Data Average Method

Average annual Secchi depth from the Lake Tahoe index station as taken by UC Davis.

 Transparency of Lake Tahoe as measured by the annual average Secchi depth.

Name Options
Data Average Method
Annual Average, 5-Year Average, Trend

Program Water Clarity


Measurements are taken in Lake Tahoe using a 25 centimeter, all white Secchi disk. The disk is lowered into the water column from a boat to a depth at which it is no longer visible by the observer, and then raised slowly until visible again. The midpoint of these two depths is called the Secchi depth. Between 18 and 37 individual Secchi depth measurements have been collected each year at an established index station. 

To download all of the water clarity data on this page please see Tahoe Open Data.


Associated Programs data not provided.