WQ – Lakes – Transparency

This data layer indicates Lake Clarity based on Secchi disk measurements in meters from surface. It was developed by the Natural Resources Research Institute using data from the Minnesota Pollution Control Agency. The concentration of total phosphorus, chlorophyll and Secchi depth are the three components used to assess lake trophic status or health. A Secchi disk measures water transparency or clarity and indicates the depth of light penetration into a lake. Secchi depth also provides an indirect measure of the amount of suspended material, algae or sediment in the water. Metrics were calculated using the 10 year average for samples collected from May through September. The average is recalculated annually.