About Secchi Disk Reading

Water quality measurements are collected using a Secchi disk, which is a weighted disk that is lowered into the water to determine how deep the sunlight can penetrate into the water. A high amount of sediment or algae causes a lower Secchi disk reading which indicates deteriorating or poor water quality.

 

Scientists from the 7 Lakes Alliance, with the help of Colby College student interns, collect water quality data on a weekly basis. These scientists have also helped us define the following water quality parameters specific to North Pond: 

• 13 feet or greater = Good

• 13-10 feet = Fair

• 10-7 feet = Poor

• 7-3 feet = Algal Bloom

• 3 feet or less = Potentially Toxic Algal Bloom

 

We post the Secchi disk readings as they are collected in an effort to keep nearby residents, lakefront property owners, local businesses, and visitors informed about our lake. This information can also be found on signs in front of Tri-Pond Variety and the former Smithfield Fire Station.