2011 Secchi Dip-In June 25–July 17

The annual Secchi Dip-In is a demonstration of the potential of volunteer monitors to gather environmentally important information on our lakes, rivers and estuaries.

The concept of the Dip-In is simple: individuals in volunteer monitoring programs take a transparency measurement on one day during the weeks surrounding Canada Day and July Fourth. Individuals may be monitoring lakes, reservoirs, estuaries, rivers, or streams. These transparency values are used to assess the transparency of volunteer-monitored lakes in the United States and Canada. Volunteers have been submitting information during the annual Dip-In snapshot since 1994.

When 5 or more years of data have been gathered on a site, it is used to determine trends. Over 2,000 waterbodies are now tracked for trends in transparency.

» Learn more about turbidity and how to measure it

» Make your own Secchi disk!

» More information about the Secchi Dip-In and how to participate