Lake Sevan is a freshwater lake in the Armenian Highlands, the largest lake in the Caucasus, and one of the largest high-mountain freshwater lakes on Earth. The surface of the lake is at an altitude of 1897 m, the depth of the lake is 80 m, the area is 1260 sq. km, the length is 70 km, the width is 55 km, and the volume is 58 billion cubic meters. The average water surface temperature in summer is 18°-23°. In winter, the lake is partially covered with ice.
The lake consists of two unequal parts – Big Sevan and Small Sevan, connected by a 5-kilometer strait, which is located between the Ardanish and Noradus peninsulas. The southern and eastern shores are wide and flat, and the northern and northeastern ones are narrow and rocky. Small Sevan is distinguished by its great depth and jagged shores. It is in this part that the largest volume of water in the lake is concentrated. The deepest place of Sevan is located near the foot of the Areguni ridge. In Big Sevan, the bottom is flat, the shores are slightly jagged, the depth does not exceed 30 meters.
Sevan is surrounded by the Geghama Mountains on the west, the Areguni Mountains on the north, the Sevan Mountains on the east and the Vardenis Mountains on the south.
28 rivers flow into Lake Sevan, the largest of which are Gavaraget, Argichi, Martuni, Karchaghbyur, Masrik, Dzknaget. Only the Razdan River flows out.
Lake Sevan has a tectonic-volcanic origin. From a geodetic point of view, Big Sevan is an ancient intermountain concavity, where a water basin existed in the distant past. A separate lake also existed on the site of Small Sevan. Young volcanic lavas, blocking the outlet of Small Sevan, raised the water level. Big and Small Sevan merged and formed today’s Sevan.
In the northern part of the lake there was the island of Sevan, which became a peninsula after the lake became shallow.
Fauna of Lake Sevan
The lake is home to unique species of fish that are not found anywhere else: Sevan beglu (barbel), Sevan khramulya, Sevan trout. The latter was previously represented by 4 subspecies, but the winter bakhtak and bodzhak subspecies have become extinct, and the existence of the remaining ones is under threat due to competing fish species that have been introduced or have entered the lake from other places: migratory whitefish (introduced from Lake Ladoga and Lake Peipus), silver crucian carp, and narrow-clawed crayfish.
The lake is an important center for the Armenian Gull population, with numbers reaching 4,000-5,000 pairs. Other birds that stop at the lake include the American Swan, Lesser White-fronted Goose, Red-crested Pochard, Ferruginous Pochard, and Black-headed Gull.
Historical monuments of Lake Sevan
Lake Sevan is of great interest to tourists. Along the entire shore there are “cyclopean” fortresses dating back to the Bronze Age (Lchashen, Ayrivank). Buildings of the Urartu kingdom (Velikukhi, the rock inscription of Rusa) and many medieval architectural monuments have also been preserved.
Lake Sevan is associated with many significant events in the history of the Armenian people. In particular, the Battle of Sevan, in which the Armenian king Ashot II the Iron defeated the Arab Caliphate troops that invaded Armenia.
One of the main attractions of Sevan is the medieval monastery of Sevanavank, which is a complex of small buildings from the 9th century. The history of the monastery begins with the settlement of several monks on the island, who built several cells and a chapel. Gradually, the number of monks increased, so by order of Princess Mariam, the daughter of King Ashot I Bagratuni, active construction of the monastery began in 874. The monastery is also known for the fact that King Ashot the Iron lived here before the battles with the Arabs, and the battle itself took place near the walls of the monastery. Today, only a few small churches and the remains of cells remain from the monastery.
To the southwest of the city of Sevan is one of the most ancient archaeological sites of the Urartian period of Armenia – Lchashen. It is famous for its archaeological complex, consisting of a fortress, burial mounds, and the remains of an ancient city. Until the mid-20th century, the complex was under water, but after the lake became shallow, archaeological excavations began here. The most ancient cultural layers discovered under the city date back to the 3rd millennium BC.
On the shore of the lake is the village of Noratus, famous for its largest cemetery of khachkars (khach – cross and kar – stone, a special type of art – decorative and architectural sculptures), numbering about 900 khachkars of different eras and styles. There are also khachkars in the village of Nerkin Getashen on the southern shore. After the water level dropped, numerous archaeological artifacts were discovered, dating back 2,000 years or more (some of them from the Bronze Age). Most of these artifacts are in Yerevan museums.
On July 26, 2012, a sunken 18-meter wooden ship was discovered at the bottom of Sevan, at a depth of about 16 meters. According to the report voiced by the discoverers, part of the find was preserved almost entirely, while the other part was damaged. It is planned to conduct underwater excavations at the site of the ship’s discovery.
The Importance of Lake Sevan for Armenia
Lake Sevan is the only major guaranteed source of fresh water in Armenia. The waters of Sevan supply most of the canals irrigating the Ararat Valley, as well as all 6 power plants of the Hrazdan Cascade. The water and fish reserves of the lake are of great economic importance.
In the 1940s and 1950s, the Sevan-Razdan irrigation and energy complex was built. Due to the deepening of the source of the Razdan River, part of the water reserves were released. From 1936 to 2000, the water level in the lake dropped by 19 m, and the area of the lake decreased by 12%.
The areas freed from water made it possible to build a railway and a highway running through the north-eastern shore.
In 1961, due to the fact that the capacity of the Sevan-Razdan hydroelectric cascade was not in demand, and the use of drained soils was ineffective due to low fertility, it was decided to stop draining the lake and raise its level by transferring water from the Vorotan and Arpa rivers. In 1981, a 48.3 km long tunnel was built from the Kechut reservoir on Arpa to Lake Sevan, after which construction of the 21.7 km long Vorotan-Arpa tunnel began. In 1988, construction was suspended due to the deterioration of the economic situation in the republic, and was completed only in 2003. During 2006-2010, the lake level rose by 25-35 cm per year.
In 1978, Sevan National Park was created to solve environmental issues.
Lake Sevan Day
Since 1999, the last Sunday of August has been declared Lake Sevan Day in Armenia. This decision was made by the Ministry of Nature Protection of the Republic of Armenia, which included in the program for the preservation of Lake Sevan events related to this day, including the cleaning of the shores of Sevan. Ecological and scout units participate in these events. The events are held under the supervision of the employees of the Sevan National Park.