Young Brunette Girl Posing In The Lake

Most lakes have at least one natural outflow in the form of a river or stream, which maintain a lakes's average level by allowing the drainage of excess water. Some do not and lose water solely by evaporation or underground seepage or both. They are termed endorheic lakes.
Many lakes are artificial and are constructed for hydro-electric power generation, aestetic purposes, recreational purposes, industrial use, agricultural use or domestic water supply.
Evidence of extraterrestrial lakes exists; "definitive evidence of lakes filled with methane" was announced by NASA as returned by the Cassini Probe observing the moon Titan, which orbits the planet Saturn.
Globally, lakes are greatly outnumbered by ponds: of an estimated 304-million standing water bodies worldwide, 91 percent are 1 hectare (2.5 acres) or less in area. Small lakes are also much more numerous than big lakes: in terms of area, one-third of the world's standing water is represented by lakes and ponds of 10 hectares (25 acres) or less. However, large lakes contribute disproportionately to the area of standing water with 122 large lakes of 1,000 square kilometres (390 sq mi, 100,000 ha, 247,000 acres) or more representing about 29 percent of the total global area of standing inland water.