Read the record
Four lake-data ideas in plain language.
A number becomes useful when you also know what was measured, where, how and when.
Depth maps
Contour lines describe measured or interpreted lake-bottom shape. They are not turn-by-turn navigation, and water levels or underwater hazards may differ from the mapped record.
Water clarity
Clarity describes how far light or a viewing disk can be seen, depending on the method. Weather, algae, sediment, season and location can change the reading.
Water quality
Water quality is not one score. Nutrients, algae, bacteria, contaminants, habitat and designated uses are evaluated with different methods and time periods.
Source dates
The observation date tells you when a sample or image was collected; an assessment date and a webpage update date mean different things. None should be read as a live condition.