Secchi Disk Program

Like a primary care physician assessing your health through multiple tests, a limnologist wDSC_0431ill compile the results of several water quality tests to determine the overall health of the lake. One standard water quality summary is the Carlson Trophic State Index Score which uses winter levels of total phosphorous (an essential nutrient for biological growth), summer concentration of chlorophyll (the dominant pigment in algae) and secchi disk depth (a measure of water clarity). Secchi Disk measurements have been used by limnologists for two centuries.

Here on Canandaigua Lake, Dr. Bruce Gilman, Dept. of Environmental Conservation and Horticulture at FLCC, has been measuring secchi disk water clarity since the 1980’s at two mid-lake stations. For the last several years, Canandaigua Lake Watershed Association volunteers have also collected weekly secchi disk data at over 16 locations around the lake. This cooperative monitoring helps us learn about the factors that affect water clarity and overall lake health.

2016 Data for Water Clarity Monitoring

The below chart illustrates current data collected from the 2016 CLWA secchi disk volunteers. Data is updated weekly. Thanks go out to our 2016 Volunteers: Dee Crofton, Gary Helming, Kevin Hefner, Scott Hill, Bruce Kennedy, Marty Lasher, Wade Sarkis, Lynn Thurston, Vickie Tucker, Bill Yust, and Steve Zumbo.

For web

Concerned about water clarity? 

See our quick blue green algae guide or visit the NYS DEC website and NYS DOH website for more information on blue green algae.  If you have any questions or see a suspicious bloom, please email or

Interested in Volunteering? 


Secchi Disk volunteers use their own boats to go out on the lake and take weekly recordings. Findings are reported electronically, which makes real-time response to a possible critical condition possible. The additional data gathered by volunteers helps us supply more detail to the ongoing “picture” developing of Canandaigua Lake.

For more information, contact the CLWA office at (585) 394-5030 or email us.