Important national and regional facilities such as dams “must remain instruments of peace and development and should never be used as instruments of war”, the International Commission on Large Dams (ICOLD) implored in October 2022 as it expressed great concern about the safety of the Nova Kakhovka hydroelectric project in the Ukraine. However, on 6 June 2023, the commission said that “the world’s worst fears were realised” when the 3.2km long, 30m high dam that impounded 20km3 of water was breached.
Located on the Dniper river in the Russian-controlled southern part of Ukraine, Nova Kakhovka dam was originally constructed in 1956 and its operator Ukrhydroenergo, Ukraine’s largest hydropower generator, said the structure was now beyond repair. The breach is believed to have been a deliberate act, with Ukraine claiming that Russia destroyed it and Russia suggesting it is Ukraine who is responsible for the damage.
At the time of the dam failure, Nova Kakhovka’s reservoir was at a record high level and a catastrophic release of water ensued. Reports suggest that the central section of dam was destroyed which progressed to the failure of the eastern side of the spillway and then loss of the hydropower plant. Ukraine’s President Volodymyr Zelenskiy holds Russia responsible for the damage and called it a deliberate crime of ecocide by the Russian occupiers, saying it was “an environmental bomb of mass destruction”.
“As a result of the detonation of the engine room from the inside, the Kakhovka hydropower plant was completely destroyed. The station cannot be restored,” Ukrhydroenergo said in a statement on 6 June, predicting that the reservoir would be drained within four days. Ihor Syrota, Ukrhydroenergo’s CEO, described the incident as a ‘barbaric act of destruction’ and said that there will be environmental consequences in addition to the immediate destruction of the station.
ICOLD condemned such action “in the strongest possible terms”, adding that the consequential cost in human, environmental and economic terms cannot be justified in respect of any military objective. UN Secretary-General António Guterres described it as another devastating consequence of the Russian invasion of Ukraine and that attacks against civilians and critical civilian infrastructure must stop. While UN Under Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, Martin Griffiths, said it was possibly the most significant incident of damage to civilian infrastructure since the start of the Russian invasion of Ukraine in February 2022. International humanitarian law is very clear, he commented, and structures such as dams must receive special protection as their destruction can cause severe loss for the civilian population. Constant care must be taken to spare civilians and infrastructure throughout all types of military operations, Griffiths added.
Expressing its dismay concerning the damage caused to the Nova Kakhovka dam, the International Hydropower Association (IHA) said that although much is still unknown about the circumstances of the incident, it is clear that communities will be dislocated, large amounts of clean energy and water lost, and livelihoods severely affected.
Eddie Rich, IHA Chief Executive, said that the worldwide hydropower community will want to join with IHA in offering sympathies to those affected by the tragedy. IHA called for infrastructure workers in Ukraine to be allowed to fulfil their duties and encouraged the association’s network to support the redevelopment and reconstruction process as and when the time comes.
Catastrophic
Previously spanning an area of more than 2000km2 and Ukraine’s largest in terms of water volume, the Nova Kakhovka reservoir was described as being “catastrophically shallow” on 26 June after flooding caused by the suspected explosion. The Dnipro River has now returned to its old channel and in some places is just a stream, while shallower parts are being exposed for the first time since dam construction almost 70 years ago.
Following the incident, Ukraine lost about 14.4km3 of water and 35% of the annual flow rate of the Dnipro River, while the water level in the Dnipro riverbed near the station is currently less than 2m.
Ukrhydroenergo confirmed that the aftermath of the explosion resulted in significant operational and environmental consequences. Despite the magnitude of the incident, the explosion did not disrupt the operating modes of several other hydroelectric power plants, and the Kyiv, Kanivskaya, Kremenchuk, and Serednyodniprovskaya hydropower plants were reported as being unaffected and functioning normally.
Nova Kakhovka dam is described as being a lifeline to the region and estimates suggest that essential water supplies to more than 700,000 people have been affected. In addition, loss of water from canal networks for irrigation purposes could prove to be critical for food production in the region. Estimates suggest the affected reservoir supplied water to more than 12,000km of canals irrigating over 500,000 hectares of cropland. A recent analysis of satellite imagery by NASA Harvest, NASA’s Global Food Security and Agriculture Consortium, shows four major canal inlets (vital for farm irrigation) have already been or are close to being disconnected. As Ukraine is a major exporter of sunflower, maize, wheat and barley, the dam destruction could have huge impacts on global food security as the region is seen as ‘a breadbasket’ for not only Ukraine but the rest of the world.
Flooding from the dam breach, which peaked at a depth of 5.6m in Kherson on 8 June, destroyed houses, roads and other crucial infrastructure, displaced more than 20,000 people and created an ongoing humanitarian and ecological crisis. Recent estimates suggest that 32 settlements on the right bank of the Dnipro River and 14 settlements on the temporarily occupied territory remain flooded. Efforts to evacuate people from these inundated areas are ongoing, and authorities are actively working to provide the affected population with drinking water and other essential resources. There have also been impacts on sanitation and sewage systems in addition to health services, with Cholera remaining the largest threat to health within the area. In addition, the receding flood water has scattered landmines far and wide in one of the most “mine contaminated” parts of the world. Although they do generally float on the water surface, there is concern they can become entangled in debris and embedded in sediment. And as the dam played an important role in regulating river flow there will now be a greater risk of flooding and drought, with warnings that unless flood defences are put in place or the dam repaired, some areas may remain unsuitable for residents to return as they are so close to the river.
Looking at environmental impacts, many believe that we have just seen the tip of the iceberg. There are fears that future agricultural activity will be reduced for many years to come as the flood water washed away the topsoil on vast areas of the farm and arable land, while fertilizers may disrupt aquatic ecosystems as they’ve been washed into the river.
The sudden surge of water downstream has had immediate and far-reaching impacts on biodiverse ecosystems, and nearly 160,000 animals and 20,000 birds are thought to be under threat, including the vulnerable Nordmann’s birch mouse and the endangered sand mole rat. In addition, the rapid draining means that vast numbers of fish will be either stranded in shallow, dried-up zones, or swept away to sea, where they will perish in the salt water.
Described as perhaps being of greater concern, is the potential dispersal of toxic compounds. More than 150 tonnes of machine oil from the Kakhovka hydro station have spilled into the Dnieper River, The flood water also carried rubbish, together with construction waste and sewage, into the Dnieper watershed, and could potentially contaminate supplies of drinking water.
“The scale of this event is enormous,” United Nations Development Programme’s Resident Representative in Ukraine, Jaco Cilliers, said. “It is crucial that we understand the full extent of its impact,” he added.
Assistance
On 22 June, the European Bank for Reconstruction and Development (EBRD) announced it was to assist in the restoration and modernisation of Ukrhydroenergo`s hydroelectric power plants in the Ukraine, including the Kakhovka plant. The primary objective of this agreement is to address the operational challenges faced by Ukrhydroenergo`s hydropower plants due to the impact of the Russian invasion and will focus on replacing critical equipment, enhancing operational reliability, and improving efficiency across the hydroelectric power plants. Potential investment opportunities will also be identified, with a particular emphasis on the reconstruction of the Kakhovka hydropower plant and its associated infrastructure following the devastating explosion in early June.
“I am grateful to the Government of Ukraine and international partners, particularly the EBRD, for their comprehensive support in implementing Ukrhydroenergo`s key task – restoring hydropower facilities. I am convinced that by working together, we will restore the lost capacity and increase the security of our energy infrastructure,” Ihor Syrota, CEO of Ukrhydroenergo, said
Ukrhydroenergo says it is continuing to implement critical measures to restore the Kakhovka hydropower complex. In particular, ongoing negotiations with the World Bank, the EBRD, and the European Investment Bank are looking at plans to construct temporary water retention dams in the upper and lower sections of the reservoir. These will enable the accumulation of water levels up to 12.7m and restore supply in the region.
Paramount priority
Dam safety must always be given paramount priority, ICOLD says, acknowledging the difficulties Ukraine is probably experiencing in assuring dam safety across the country, due to the shortage of operational and maintenance expertise caused by the displacement of people. At its annual meeting in Sweden which was held only days after the dam breach in June, ICOLD said that the incident and its consequences were a major concern to the 1200 assembled delegates from 77 countries around the world, and offered to support and assist Ukraine in any related area that may be of benefit.
This article first appeared in International Water Power magazine.
