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Water Clarity (Secchi) Monitoring



Water clarity monitoring is a process in which the volunteer lowers an 8” diameter, black & white disc (“Secchi disc”) into the deepest part of the lake to determine how far down they can see the disc as it is lowered. Water clarity monitoring is done every 10-14 days throughout the open-water season. Water clarity is a quick way to estimate lake health, and it plays an important role in determining the types of plants and animals that a water body can support. 

Water Clarity (Secchi) How-to Video


Want to know what water clarity monitoring entails? Haven't used your Secchi disc in a while and want to refresh your memory?

Check out this great how-to video!


Water Clarity (Secchi) Training Resources


Water Clarity (Secchi) Monitoring Forms


Secchi Only monitoring form (3200-100)

Use this form if you only monitor for water clarity on your lake.


Secchi and Chemistry monitoring form​ (3200-099)

Use this form to submit temperature and dissolved oxygen profiles along with Secchi depth.

For a list of ALL monitoring forms, click here (exit UWEX Lakes)


Water Clarity (Secchi) Resources


Secchi Dip-in​ (exit UWEX Lakes)

Volunteers have been submitting information during the annual Secchi Dip-in since 1994! Please join them in this international effort to track changes in water clarity.

Remote Sensing - using a satellite to track water clarity trends (exit UWEX Lakes)

Since 1999, Citizen Lake Monitoring Network volunteers have been assisting in a collaborative research effort with the University of Wisconsin Environmental Remote Sensing Center by taking water clarity readings on dates when the satellites were overhead. The volunteers' participation has allowed the University to successfully calibrate computer programs, which enable satellite imagery to be used to predict water clarity and other water quality parameters on lakes. The researchers at the Remote Sensing Center are continuing their research. The ultimate goal is to put the satellite data into everyday use by making the water clarity data derived from the satellite imagery available to the public.

Which satellite path includes my lake?

2024 Satellit​e schedule​

Water Clarity Award Recipients

Click here​ to see who has received Citizen Lake Monitoring Network awards. (exit UWEX Lakes) 

Interviews from 20-year CLMN Volunteers (PDF)


Use this short guide to interpret the data that is included in your lake's annual reports.​




What else can volunteers monitor?




For more information, contact

Paul Skawinski, Citizen Lake Monitoring Network Educator

(715) 346-4853

Or go to

©1993- University of Wisconsin-Stevens Point