Volunteers, DNR staff, county staff and others collect water clarity, temperature
and dissolved oxygen, as well as other water quality data, on lakes across Wisconsin.
Around 1,000 volunteers are currently active, and the network has been going strong
since 1986. Water clarity is measured with a black and white disk called a "Secchi
Disk".
Satellite images are used to retrieve water clarity data for lakes across the state.
This effort began in 1999 when the University of Wisconsin-Madison Environmental Remote
Sensing Center (ERSC) developed a model for the retrieval of water clarity data from
satellite images and Citizen Lake Monitoring Network volunteers provided on-the-ground
Secchi data to calibrate this model for each satellite image. Water clarity data was
retrieved for over 8,000 lakes statewide between 1999 and 2001. The DNR continues to
analyze data in this way today in its remote sensing program.