Extent of available data.
Data Source:MN Pollution Control Agency, Natural Resources Research Institute
Tags:Lakes, Water Quality
This data layer indicates lake clarity based on Secchi disk measurements. It was developed by the Natural Resources Research Institute using data from the Minnesota Pollution Control Agency. 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. Clarity was calculated using the 10 year average Secchi depth for observations collected from May through September. The average is recalculated annually. The concentration of total phosphorus, chlorophyll and Secchi depth are the three components used to assess lake trophic status or health.