To stand in front of Georgia’s Enguri Dam is to marvel at one of the world’s most ambitious pieces of structural engineering. All that separates you from 1.1 billion cubic metres of water is an enormous concrete wall, 271.5 metres tall and 650 metres wide.
The dam on the Enguri river, north of the town of Jvari in the mountains of north western Georgia, is the second tallest arch dam in the world. It was built in the 1970s as part of the Enguri hydropower plant to provide electricity for the Soviet Union.
Today it produces over 40 per cent of the electricity consumed in Georgia and allows the country to sell surplus power to Turkey and Russia and to take part in the Kyoto Protocol’s Clean Development Mechanism.
But reliable power supply and the safety of the dam have only been restored recently, after years of difficulties and headaches for the 550 people working there and for all Georgians, affected by constant electricity cuts.
Their maintenance neglected, one of the plant’s five power units was shut for over 15 years and the other four were not able to work at their full capacity. At the same time, the dam’s structural stability and working conditions had deteriorated, with galleries inside the dam frequently flooding. International experts identified the risks that would compromise the future of the dam back in 1994. The operations needed to remedy the situation were too costly for Georgia to bear alone.
From 1998 onwards, the EBRD was involved in the renovation of the Enguri hydropower plant, covering civil engineering works on the structure as well as the upgrade of the generator units, with financing totalling €58 million.
The project was co-financed by the European Investment Bank (EIB) with €20 million and the European Union provided grants for €9.4 million and additional €5 million through its Neighbourhood Investment Facility (NIF). In addition, grant funds from the Swiss government were used to finance engineering consultants at the design phase of the project.
Georgia: Enguri dam keeps the power flowing
The EBRD’s 15-year mission to renovate the world’s second biggest arch dam – now the Enguri HPP again provides more than 40% of Georgia’s electricity needs.
Notwithstanding a life-long familiarity with the plant’s story, the landscape with which it has merged and its hidden meanders, Levan Mebonia takes nothing for granted. He is the Chairman of state-owned Engurhesi Ltd, the company that manages the plant.
Walking in the giant belly of the dam means clocking up the miles. In the dim electric light of the tunnels Mr Mebonia can identify exactly the five kilometres repaired and strengthened with cementing during the upgrade works.
The EBRD’s financing also paid for the upgrade of the high pressure gallery that brings the water from the dam to the power units. Located below the level of the reservoir, it is structurally the most dangerous area of all. The security of the site was also improved in the valve hall.
“The valves are for shutting off the main tunnel in an emergency or for repairs. After the collapse of the Soviet Union we were unable to maintain them for lack of finance and the valves stopped functioning,” Mr Mebonia explained. “Now it's all restored, new equipment installed and it all works as it should.
“I have worked here since I was 22 years old,” he said. “In that sense, it has been my life's mission.”
Thanks to the upgrade, each unit at the plant is generating between 10 to 15 per cent more power. In 15 years the loan will be repaid and the life of the dam is assured for much longer still, providing a reliable resource of clean energy for Georgia and beyond.