Sevan

Largest lake in Armenia, covering an area of 1,360 sq km/525 sq mi. Lake Sevan lies in a plateau of the Caucasus Mountains, 1,903 m/6,243 ft above sea-level. Its average depth is 86 m/282 ft. A number of tributaries flow into the lake, but its sole outlet is the River Razdan.

Lake Sevan consists of two basins, of which the smaller in area, lying to the northwest, is much the deeper. The lake rarely freezes over completely in winter.

After leaving Lake Sevan, the Razdan flows into the River Araks, and has a chain of power stations on it, built since World War II. As a result of their construction and operation, the level of the lake was lowered several metres, causing destructive microclimatic and vegetational changes around its shores. In an attempt to redress the situation, a long-term construction scheme lasting from the early 1960s to 1981 was undertaken to divert water into the lake from the River Arpa via a tunnel.