Lake Sevan (Armenian: Սևանա լիճ Sevana lich) is the largest lake in Armenia and the Caucasus region. It is one of the largest fresh-water high-altitude lakes in the world.

Lake Sevan is situated in the central part of the Republic of Armenia, inside the Gegharkunik Province, at the altitude of 1,900m above sea level. The total surface area of its basin is about 5,000 km2, the lake itself is 940 km2, and the volume is 34.0 bln cubic metres. It is fed by 28 rivers and streams. Only 10% of the outgoing water is drained by the Hrazdan (Razdan) river, while the remaining 90% evaporates.

Before human intervention dramatically changed the Lake Sevan ecosystem, the lake was 95 metres deep, covered an area of 1,360 km² (5% of Armenia's entire area), had a volume of 58 km³ and a perimeter of 260 km. The lake surface was at an altitude of 1,916 m above sea level.

Along with Lake Van and Lake Urmia, Sevan was considered one of the three great lakes of the historical Armenian Kingdom, collectively referred to as the Seas of Armenia; it is the only one within the boundaries of today's Republic of Armenia. The Sevanavank peninsula (formerly an island) is the historic area of the lake at its northern shores.

Historical names of the lake are Gegharkuni (Armenian: Գեղարքունի), Sea of Gegham (Armenian: Գեղամա ծով Geghama tsov), Lychnitis (Greek and Latin), and (Turkic-Azerbaijani: Gökçe or Göyçə). On Russian map of 1902 the name of the lake is given as "Gokce or Sevanga". The name Sevan literally means "Black Van" referring to Lake Van. It is said that long ago, Armenians came from the areas around Lake Van to Lake Sevan. They saw that the lake was dark and almost black yet reminded them of Van, therefore the lake was called Sevan. The Old Georgian name for the lake drew from the name of its old inhabitants (i.e. before the fall of Urartu), the Èrs- it was called "Lake Ereta" by Leonti Mroveli in his Georgian Chronicles.

For a long time, the word "Sevan" was known to be connected with the monastery in the small island of the lake Sevan called "Sev Vank" ("Black Monastery") built with black tuff. And this was known to be the etymology of name Sevan. But it was obviously wrong, because the word "Sevan" was older than the monastery itself. Finally, the etymology of word "Sevan" was found in Teyseba (the cuneiform inscription by Rusa I (730—714 B.C.)). This inscription was a "birth certificate" of the term "Sevan". It was mentioned as "Suinia" or "Tsuinia". Thus, the etymology of "Sevan" is similar to Yerevan's etymology. It was named after simple geographical names, as water, river, lake, mount, etc. Later scientists found that "Suinia" or "Tsuinia" means "lake" or "basin" in Urartian.

In 1910 Soukias Manasserian, one of the civil engineers behind the interventions that caused the Aral Sea disaster, published a study Evaporating billions and stagnation of the Russian Capital, which suggested the lowering of the lake's surface to 45 meters and the use of the water for irrigation and hydroelectricity.

In Joseph Stalin's era the plan was slightly modified: the water level would be reduced by 55 meters (5 meters more than suggested by Manasserian), the perimeter would shrink to 80 km and the volume to only 5 km³. Nut and oak trees would be planted on newly acquired land, and introducing some trout species into the remainder of the lake would increase fishery production tenfold.

The Armenian Supreme Soviet approved the plan without consulting the local people, and major work started in 1933. The river bed of the Hrazdan was deepened, and construction of a tunnel 40 meters below the original water level was begun. The work was delayed due to World War II and was only finished in 1949. The water level then began to fall by more than one meter per year.

As a result of these activities, the level of the lake fell by 19.01m, from its original of 1,915.9m. The lake is now 1,896.86 meters high; the volume has declined from 58.5 billion cubic meters to about 34.0, and the surface area has shrunk from 1,416.2 km2 to 1,238.1 km2.

An ecological disaster like in the Aral Sea was avoided when the Stalinist era ended in 1956 and the project and its consequences were reviewed thoroughly. As there were difficulties with planting oaks and nut trees, and with fishery, the Sevan Committee was established with the mission "to raise the level as much as possible". Hydro-electric power stations on the Hrazdan would be replaced with thermal power stations. In 1962 the water level stabilized at 18 meters below the original level, but two years later the lake started to "bloom" due to entropic algae.

In 1981, a 49.3 km tunnel was constructed, diverting water from the Arpa river (from a reservoir near Kechut) to the lake near Artsvanist. The water level in the lake rose only 1.5 metres, so another 21.7 km tunnel was begun from Vorotan River (further south from Kechut). Eighteen kilometers of this tunnel were completed before the collapse of the Soviet Union, but in 1988 Azerbaijan imposed an economic blockade on Armenia due to the Nagorno-Karabakh conflict, and the work had to be stopped.

The Armenian government completed the Vorotan tunnel in 2004 and was opened on April 26, 2004. The level stabilized at 20 meters below the original, and the lake's area is now 940 km².


On March 2, 2012 the chairman of the presidential committee on Lake Sevan issues stated that in line with the laws adopted since 2001, the water level of the lake had risen by 380 cm and the lake stands today at 1900.19m high. 


The Island Monastery

The 9th century Armenian monastery of Sevanavank

Originally made from three churches, the monastery was built on an island. Receding waters in the mid-twentieth century created the current peninsula. The island was uninhabited until the end of the eighth century A.D., when monks built a chapel and a group of cells. The monastery was founded in 874 by King Ashot I, the first king of the Bagratid kingdom, and his daughter Mariam. Two churches remain, St. Arakelots and Astvatsatsin. The island monastery was, according to historians of the time, used both for worship and pilgrimage, and as a place of exile for Armenian noblemen who had fallen into disgrace. It also was the residence and headquarters for Ashot I, from which he led a battle against invading Arabs beginning in 859.

During the battles monks and clergy fought alongside the army to defeat the Arabs, but repeated Arab and Ottoman invasions continued. The monks on the island continuously led battles to protect the monastery, and such was the life in and around the monastery for almost 500 years until the Persians and the Ottomans divided the Armenian kingdom. The monks in Gegham-kiunik specialized in medicine, and some of their natural cures are still used, based on herbs that grow in the wild around the lake. The monastery continued to function until the 20th century; the last monk left in 1930. Today the monastery is maintained by the Church, which maintains a summer retreat for seminarians on the peninsula.