Lakes can also form in volcanic calderas. Among the most famous crater lakes is Oregon s Crater Lake. Ocean currents may deposit sediments along a shoreline, cutting off bays which then become coastal lagoons . Many artificial lakes have been created as sources of hydroelectricity, water for irrigation and other uses. Lakes are like animals in that they are born, grow, then die.
Some lakes disappear when their source of water is diminished.
An example is Utah s Great Salt Lake, which was much larger during the wetter, cooler Ice Age. Lakes are also erased through a process called eutrophication , in which a lake s basin is filled with sediments. Just imagine shoveling sand into a swimming pool, forcing the water out. Over time, a lake becomes shallower until it may become a swamp or marsh a watery grassland or wooded area. Next, it transforms into a bog, with little or no standing water.