Water School

The level of water in all lakes fluctuates, raising during years of higher amounts of rainfall and snowmelt and falling during periods of drought. The Environmental Protection Agency has been measuring the fluctuations of the Great Lakes, the largest natural lakes in the United States, since the 1860s. Similarly, water levels in reservoirs, human-made lakes, fluctuate because of evaporation, a lack of rainfall, water supply use, and water flow requirements. Levels tend to be relatively lower in ...