Political unrest and civil war in Georgia complicated access to the 1,300-MW Enguri hydro facility and dam. The 20-year-old operating agreement for this facility no longer fits local needs, and work is under way to ensure reliable access to electricity from hydro plants.
By Theresa Sabonis-Helf
Every morning, engineers and senior plant operators assemble in Zugdidi, Georgia, for their commute to the 1,300-MW Enguri hydropower facility. Most of these 60 to 80 workers take a specially designated bus. A few of the most senior employees drive their own cars, outfitted with special license plates. Their 30-km commute takes 80 minutes, with half of that time spent at the ABL (administrative border line) check point.
Once they arrive at the Enguri plant, these people join about 400 other employees to run Enguri, which provides electricity to the Republic of Georgia and its breakaway province of Abkhazia. Ironically, most of the power plant workers identify as neither Georgian nor Abkhaz. They are primarily Megrelian, an ethnic minority with a distinct language and culture. Their common language, they say, is key to keeping tensions inside the facility low, regardless of what happens in the world outside.
The Enguri facility is a rare example of cooperation between two distinct governments, born of necessity. Enguri Dam is located on Georgian territory, while the power plant is in the Gali district of Abkhazia, which broke away from the country in 2008 (see Figure 1). The power plant provides all of Abkhazia’s electricity and up to one-third of Georgia’s. Without Georgia’s cooperation, Abkhazia has no operating source of electricity, but without Abkhazia’s cooperation, Georgia loses access to its largest source of electricity.
Both sides recognize Georgia as the owner and operator of Enguri, but that recognition comes at a significant price. In exchange for ownership and access, Georgia must supply 40% of the power generated by Enguri to Abkhazia - at no cost. This agreement was signed in 1996 and has held for more than 20 years but may not be sustainable into the future. Georgia and Abkhazia exist in entirely different energy economies. Georgia has engaged in aggressive energy reform, operates the most sophisticated grid in the region, and seeks to export seasonal electricity to its neighbors. Abkhazia neither meters its electricity nor charges its customers. Decades of one-sided sectoral reform have led to an imbalance in which consumption per capita in Abkhazia is 10 times greater than consumption per capita in Tbilisi, Georgia’s capital city.
Enguri Dam, the second-highest arch dam in the world, is an engineering marvel, designated a Distinguished Cultural Heritage Site by the Georgian government. But as maintenance cost rises and the two governmental systems increasingly diverge, the preservation of Enguri has become more politically contentious.
In the 1950s, Soviet planners began designing a chain of dams and power plants to harness the powerful but highly seasonal Enguri River, with its estimated hydropower potential of 21 x 109 kWh per year.1 Planners envisioned multiple power complexes along the river, but as the Soviet Union came under increasing financial strain in the 1980s, only Enguri and its tailrace facility, 340-MW Vardnili, were completed.
Construction at Enguri began in 1961, and the powerhouse was opened officially in 1978, but the facility was still incomplete. For example, the dam was only half the height of its intended design because the scaffold towers and fixed crane used to move concrete had not been placed at the correct angle and so could not reach one corner of the dam to complete its intended height. Solving this problem required emergency cementing and nearly a decade of quiet cooperation with Canadian and U.S. firms. The dam was finally completed and the reservoir fully impounded in 1988.
|This view, from the top of Enguri Dam, shows that the river downstream from the dam has low water flow because the dam shunts water into a pressure tunnel.|
The reservoir has a capacity of 1.1 billion cubic meters and remains at working capacity when at 65% to 75% of this level. The power facility relies on a 9.5-m-wide, 15-km-long pressure tunnel, fed by two water intake towers. This reinforced concrete tunnel runs mostly within the mountains but moves into exposed pipes at two “aqueducts” en route to the powerhouse. The tunnel traverses 9 km of Georgian territory and 6 km of Abkhaz-claimed territory.
Water flows from the pressure tunnel into an equalizing reservoir and continues in five streams, which power the five main turbines. After exiting the turbines, water flows into an artificial lake directly downstream. Below that lake is the Vardnili tailrace facility, beginning with 220-MW Vardnili-1 and followed by a series of three turbines, each 40 MW. From there, water flows via canal into the Black Sea.
Enguri after independence
In 1995, Georgia requested international assistance to rehabilitate Enguri. Inspectors discovered a hydro plant in crisis. The review, conducted by Hydro-Quebec, noted the dam was “in a rare state of dilapidation.” Due to years of civil war, not only had regular maintenance been neglected, the facility had been looted of much monitoring equipment and wiring and many mechanical instruments.
The agreement for operation of the facility and provision of free power to Abkhazia dates from the civil wars of the 1990s and was achieved in 1996. The agreement was a reflection of the Georgian government’s inability to control the territory on which the power plant was located. Addressing that “rare state of dilapidation” could not be done without a guarantee of access. Agreeing to provide up to 40% of the electricity produced ensured that repairs could be done. The Georgian officials hoped that Abkhazia would not use a full 40% and Abkhazia might eventually reintegrate into a more prosperous and stable Georgian state.
Although tensions between Abkhazia and Georgia did not dissipate, technical cooperation was secured. Phase I of internationally-financed repairs (1996 to 2001) focused on re-establishing the capacity to monitor the facility. Phase II (2005 to 2009) responded to the dangers revealed by better monitoring. Phase II included extending the grout curtain; repairing the pressure tunnel; lining the galleries and securing access to the dam foundation, portals and intake; installation of a new stoplog for the low-level outlets; waterproofing the valve chamber; and other activities focused on reducing seepage and securing safe access and operation conditions.2 Two of the main turbines were also rehabilitated.
Enguri was well on its way to restoring its nameplate capacity when the August 2008 war broke out, involving Russia, Georgia, and the breakaway republics of South Ossetia and Abkhazia. After Georgia’s crushing defeat, the de-facto government of Abkhazia declared independence.3
|Enguri Dam is in Georgia and the power plant is in Abkhazia. (map courtesy Gavin Helf)|
Georgia was then faced with a curious legal challenge regarding the dam. How could cooperation and investment take place when it must involve the government of Abkhazia - an entity Georgia did not recognize as legal? Six months after the war, Russia and Georgia arrived at a secret agreement to manage Enguri involving a third party - a Russian company. But the Russian company, Inter-RAO, leaked the agreement (showing that Georgia was bypassing Abkhazia to negotiate directly with Russia). The Georgian government argued Inter-RAO was offering a more workable situation than the 1996 agreement, but public outcry forced the Georgian government to abandon the agreement, even as outcry from Abkhazia caused the Russian government to step back from further negotiations.
Although control of the facility (even during the 2008 war) has been greatly improved from the early years, there have been difficult years. In response to electricity emergencies, the facility has on occasion been operated in a risky manner. Winter - when power is needed most acutely - is the dry season. The lowest level to which the reservoir has been drawn was 407 m, which posed some danger of deformation to the dam, as well as drawing significant sediment into the tunnel. In more recent years, the facility has not been drawn below 410 m (the absolute minimum). The current parameter - above 420 m - is enforced in an effort to limit silt in the tunnel.
The next phase of repairs, to begin in March 2018, will focus on overdue work on the pressure tunnel. The tunnel was dewatered in February 2017 for a damage assessment led by the Enguri engineers. Fourteen companies competing for a €30 million (US$34.3 million) repair contract were invited to join the inspection before submitting their proposals. Inspectors found that the most significant damage is to the tunnel floor, which is reportedly so deeply potholed that two of the three small trucks used in the inspection were destroyed and had to be towed out. The final contract is expected to be awarded by October, but plant engineers expect repairs will force a minimum of three months’ closure of the tunnel - and that the cost of replacement electricity is likely to equal the cost of the repairs.
The engineers reflect some concern that little money will be left for addressing significant siltation problems. Notable among the indicators of siltation is that the stoplog used to adjust the flow of water, especially during repairs, which was installed fewer than 10 years ago, is no longer fully usable due to sediment blockage. Sedimentation is a problem for the basin, tunnel and drainage canal at the far end of the facility, below Vardnili. However, it is unlikely that additional money will be allocated soon for addressing this problem.
Enguri is capable of operating near its nameplate capacity in high-water months. Current operational capability of the lower Vardnili complex is unclear because the 2008 war interfered with the completion of renovations. The turbines produce some electricity but far below nameplate capacity, and one turbine is said to be fully submerged.
Now, 21 years later, the 1996 agreement still exists but other circumstances have changed. Georgia began major reforms in metering, billing and demand reduction in 2002. Georgia was recently accepted into the European Energy Community, an acknowledgement of the extent of reforms achieved. Meanwhile, Abkhazia’s demand remained at Soviet levels, with no significant gains in efficiency and no new sources of power.
In recent years, both economies have experienced an upsurge in electricity demand. Georgia, led by the hospitality sector, has seen a dramatic increase in summer demand, driven by air conditioning. In 2016, for the first time, July to August demand was almost as high as winter demand. Abkhazia’s demand also took a sharp upward path after the 2008 war, driven in part by the significant Russian military presence in its territory (an estimated 5,000 troops plus family members occupy three Russian bases). Abkhazia (population 241,000) now consumes more electricity than Georgia’s capital of Tbilisi (population 1.2 million).
|This access tunnel leads to the control room at Enguri.|
According to its government sources, Georgia provided 17.31% of all its power supply to Abkhazia in 2015. With the rise in Abkhaz demand, the 40% provided for in the 1996 agreement has become a guaranteed minimum amount of power for Abkhazia regardless of Enguri’s production. In recent years, during low-flow seasons, Abkhazia has sometimes taken all the power generated from Enguri, and during past repairs and inspections, Georgia has purchased power from Russia to keep the lights on in Abkhazia. Georgia has been willing to do this because the government perceives that shortages in Abkhazia lead to load-shedding Gali District first. Gali is the only district of Abkhazia with Megrelians (ethnic Georgians) in a clear majority, and many residents maintain their Georgian passports. Georgia is democratic and more prosperous than it once was, but citizens now pay for electricity and are increasingly skeptical about providing free power to Abkhazia.
Georgia committed to further develop and establish a competitive energy market by becoming a member of the Energy Community Treaty. As it moves toward a one-hour trading market in electricity (necessary to enhance trade with neighbors including Turkey), Abkhazia will pose a significant challenge. Ministry officials identify the uncontrolled Abkhaz consumption as being a challenge at least as big as the challenge of Enguri itself. As Georgian demand is growing faster than anticipated - with 7.7% growth expected in 2017 - Abkhaz uncontrolled demand appears ever more untenable.
As the summer high-water season comes to a close, the engineers and senior power plant operators continue their daily commute. Abkhazia has closed 17 of the 19 crossing points in the area. The Enguri Bridge crossing point closest to the plant remains open, and the Enguri bus still has the right to skip to the front.
The way forward
The government of Georgia has two big ideas for the future of electricity. The first offers Abkhazia more hydropower in exchange for better demand management. The second involves a new era of hydropower for Georgia.
First, Georgia has offered to work to return Vardnili (which is under Abkhaz control and not included in the 1996 agreement) to production and even purchase any surplus power, if Abkhazia begins taking steps to meter and collect. Georgia has also offered to work on improving Abkhaz transmission, where losses are an estimated 20%. Georgian government officials are not surprised that Abkhazia has not accepted the offer.
Having experienced first-hand the political difficulties of metering and raising rates, they understand why the fragile Abkhaz government is reluctant to make unpopular reforms, even if failing to do so damages Enguri’s long-term viability. The Georgians may get some help from Russia in changing Abkhazia’s mind. In 2016, when Abkhazia required supplemental power (due to low water levels), Georgia provided 60%, while Russia provided a reputed 40%. Georgia provided its portion for free, but Russia deducted the cost of its contribution from Abkhazia’s annual assistance package. Russia is likely to do the same this year (for the Enguri inspection period) and next year (during the repair work).
|On this day in October, Enguri Reservoir is releasing 70 cubic meters of water per second per unit. The summer maximum is 90 cms.|
But there is little Georgian optimism regarding electricity sector reform in Abkhazia. Most efforts have focused on the second goal: increasing Georgia’s installed hydropower capacity. The Ministry of Energy argues that development of the Enguri River upstream of Enguri Dam is critical. With more hydropower, water in the basin can be optimized, more water can be secured for winter, and the Enguri hydro plant will come to play a smaller overall role in Georgia’s growing electricity sector.
With these goals in mind, the Georgian government has pushed hard for completion of 700-MW Khudoni, which was begun in 1979 and abandoned in 1989. They have also moved forward with developing Nenskra, a 280-MW facility north of Khudoni. These two projects have generated considerable controversy, but the government of Georgia remains committed to seeing both through to completion. Nenskra is well on its way: Ground breaking occurred in September 2015, and K-Water of South Korea is Georgia’s Joint Stock Company partner for the facility.
Power plants in the Enguri cascade are not the only goal - Georgia has completed 17 new plants in recent years, and 14 hydropower facilities with a total capacity of 785 MW are under construction.4 Georgia is determined to have a hydropower future.
1de Goumoens, P., and B. Quigley, “Rehabilitation and improvement to the monitoring equipment and data processing for the 272m high Enguri arch dam in Georgia (CIS),” Dam Maintenance and Rehabilitation II, Taylor and Francis Group, London, 2011, pages 93-100. The authors note economically feasible potential is closer to 10-11 x 109 kWh per year.
2Phase I loan was $48.75 million and Phase II €40 million. “Development Coordination: Georgia Regional Power Transmission Enhancement Project,” Asian Development Bank, 2016.
3Only a small number of states, including Russia, recognize Abkhazia as an independent state. The United Nations considers Abkhazia to be an autonomous republic of Georgia. The territory includes an estimated 250,000 residents, or 5% of Georgia’s total population.
4These include 15 hydro, 1 thermal and 1 wind plant with a total capacity of 440 MW (representing $570 million). Fourteen hydro plants are under construction, representing a total investment of US$2 billion. Data from USAID, Georgia, as of November 2016.
This report is based on interviews with the leadership of Enguri Dam and the Enguri project and would not have been possible without the assistance of Tamar Gegechkori of the Rondeli Foundation in Tbilisi.
Theresa Sabonis-Helf is Professor of Security Studies at the National War College/National Defense University and an Adjunct Professor in the Science, Technology and International Affairs program at Georgetown University. The opinions in this article are solely those of the author and do not reflect the official position of the National Defense University, Department of Defense, or U.S. Government.