Lake Tana and Lake Sary-Chelek, are natural lakes?
Lake Tana Lake Tana (also spelled T'ana, Amharic: , "Ṭana Ḥäyq ", "T’ana Hāyk’ "; an older variant is Tsana, Ge'ez: ጻና "Ṣānā"; sometimes called "Dembiya" after the region to the north of the lake) is the source of the Blue Nile and is the largest lake in Ethiopia. Located in Amhara Region in the north-western Ethiopian Highlands, the lake is approximately 84 kilometers long and 66 kilometers wide, with a maximum depth of 15 meters, and an elevation of 1,788 meters. Lake Tana is fed by the Lesser Abay, Reb and Gumara rivers. Its surface area ranges from 3,000 to 3,500 km², depending on season and rainfall. The lake level has been regulated since the construction of the control weir where the lake discharges into the Blue Nile. This controls the flow to the Blue Nile Falls (Tis Abbai) and hydro-power station.
Yerevan Lake Yerevan Lake (Armenian: Երևանյան լիճ ("Yerevanyan lich")) is an artificial reservoir located in the capital of Armenia in Yerevan. It was formed between 1963 and 1966, to be opened in 1967.