Lake Sevan is 78km and 56km wide at its broadest point: almost an inland sea! It's set at an altitude above 1900m, and its barren mountainous shores are truly beautiful. Colors change constantly, and the variety of hues of blues and purple is just fascinating.
In 1910, the Armenian engineer Manasserian proposed to reduce the depth of the lake from 95m to 45m. He hoped to gain arable land on the lake shores and use water to produce electricity. His project was put into practice under Stalin, and completed by 1949. Yet problems soon arose: trees didn't grow on the shores and the fish catch reduced drastically. The use of water for irrigation was stopped in 1965 and the water level then stabilized 18m below original level. It was then decided to replenish the lake (!) and a tunnel was built to bring 200 million cubic meters of water each year from the river Arpa. Completed in 1981, this tunnel only raised the water level by 1.5 m and a second tunnel was deemed necessary to deviate the Vorotan into the Arpa and thus into the lake. Only 18 km out of 22 of this second tunnel were ever completed, and the first one is now in a poor state. In 1988, with the closure of the Metsamor nuclear power station (due to the earthquake) and the blockade cause by the Nagorno Karabagh war, the power station had to be used at full rate and the lake level plunged 20m below the original level (area: 940km2 instead of 1360km2 originally).