Lake Sevan

Lake Sevan (Armenian: Սևանա լիճ, Sevana lič̣) is the largest body of water in Armenia and the Caucasus region. It is one of the largest freshwater high-altitude lakes in Eurasia. The lake is situated in the central part of Armenia, in the Gegharkunik Province, at the altitude of 1,900 m (6,200 ft) above sea level. The total surface area of its basin is about 5,000 km² (1,900 sq mi), which makes up 1/6 of Armenia's territory. The lake itself is 1,242 km², and the volume is 32.8 billion m³. It is fed by 28 rivers and streams. Only 10% of the incoming water is drained by the Hrazdan river, while the remaining 90% evaporates.

Sevan provides some 90% of the fish and 80% of the crayfish catch of Armenia. It has significant economic, cultural, and recreational value. Its only island (now a peninsula) is home to a medieval monastery.

Sevan was heavily exploited for irrigation of the Ararat plain and hydroelectric power generation since the 1930s. Consequently, its water level decreased by around 20 meters and its volume reduced by more than 40%. Two underground tunnels were later built to divert water from highland rivers, which halted its decline and its level began rising. Before human intervention dramatically changed the lake's ecosystem, the lake was 95 m (312 ft) deep, covered an area of 1,416 km² (5% of Armenia's entire area), and had a volume of 58.5 km³. The lake surface was at an altitude of 1,916 m above sea level.