Lava Lake In Ethiopia

Many lakes are artificial and are constructed for industrial or agricultural use, for hydro-electric power generation or domestic water supply, or for aesthetic or recreational purposes.
Etymology, meaning, and usage of "lake"
The word lake comes from Middle English lake ("lake, pond, waterway"), from Old English lacu ("pond, pool, stream"), from Proto-Germanic lakō ("pond, ditch, slow moving stream"), from the Proto-Indo-European root leg'- ("to leak, drain"). Cognates include Dutch laak ("lake, pond, ditch"), Middle Low German lāke ("water pooled in a riverbed, puddle"), German Lache ("pool, puddle"), and Icelandic lækur ("slow flowing stream"). Also related are the English words leak and leach.