Enguri Dam

The Enguri dam lies north of the town of Jvari in the narrow canyon of the Enguri, where the river leaves the mountains of Svaneti for the Colchian plain. It is a concrete arch dam 271.5 metres high and 728 metres long along the crest, the second highest concrete arch dam in the world and, in the former Soviet Union, second in height only to Nurek: it consists of a 50-metre plug and, upon it, the arch proper of 221.5 metres, 52 metres thick at the top of the plug and 10 at the crest. The body of the dam holds seven spillway openings five metres across, and the crest twelve half-bays passing up to 2,700 cubic metres of water a second. The dam forms the Jvari reservoir, with a full volume of 1,110 million cubic metres and a useful one of 676 million.

The Enguri plant is a dam-and-diversion scheme: part of the river's flow is carried from the Enguri by a pressure tunnel 9.5 metres in diameter and more than 15 kilometres long into the basin of the Eristskali, where the five 260-megawatt units of the underground station work at a design head of 325 metres (up to 410); the installed capacity is 1,300 megawatts and the mean annual output 4.4 billion kilowatt-hours, making it the largest hydropower plant of the South Caucasus, which supplied nearly half of Georgia's electricity. The cascade also includes the four Vardnili plants on the Eristskali. The dam, the intake and part of the tunnel lie on territory controlled by Georgia, the rest of the tunnel, the powerhouse and the Vardnili plants in occupied Abkhazia, so the two sides operate the plant jointly: by the agreement of 1992 the output is shared 60 per cent to Georgia and 40 to Abkhazia, but since 2016 Abkhazian consumption, driven in part by cryptocurrency mining, has risen sharply and from November to February absorbs the plant's entire output.

The first plan for a power station on the Enguri was drawn up by Italian engineers in 1913–1914, but the small plant was never built. In the Soviet period Nikita Khrushchev first favoured a great dam on the Bzyb, but his experts warned that a Bzyb dam would erode the beaches of Pitsunda, and the choice fell on the Enguri, where the effect on the coast was less. The design of the dam and plant was developed in the 1960s and completed in 1970; the chief engineer of the arch dam was Vadim Bronshtein. Construction began in 1961, the dam came partly into operation in 1978 and was completed in 1987. In the early 1980s a chain of radio relays was built to link the Enguri dam with the Khudoni dam then under construction, powered by eight radioisotope thermoelectric generators; the Khudoni works stopped as independence approached, the stations were abandoned and the generators lost, six being found in 1998, 1999 and 2001, the find of 2001 causing the Lia radiological accident, while two remain unaccounted for.

In 1994 engineers of Hydro-Québec found the dam "in a rare state of dilapidation"; in 1999 the European Commission granted 9.4 million euros for urgent repairs, and in all the EBRD, the European Union, the Japanese government, KfW and the government of Georgia lent 116 million euros. From 2004 Voith Siemens Hydro rebuilt the units: unit 3, out of service since the mid-1990s, restarted on 20 October 2006, then units 2 and 4, and in 2011 the European Investment Bank lent 20 million euros to finish the rehabilitation and secure the safe passage of water through the Vardnili cascade to the Black Sea; the capacity, long limited to 40 per cent of the possible, rose to 950 megawatts in 2010. In August 2015 the dam was granted the status of a cultural heritage monument, since 2022 it has been a member of the European Route of Industrial Heritage, and it has become a visitor attraction.

The dam lies north of Jvari beside the road to Mestia, about 40 kilometres from Zugdidi; the downstream face and the canyon can be seen from the road. Since November 2021 the dam receives visitors on tours run by Enguri Attractions: a walking tour to the viewing platform, a short tour onto the dam with a view of the water intake, and a full tour that takes in the crest, the tunnel at the 315 level, the perimeter tunnel and the dam shield section; check tickets and times on enguridam.ge.