The Kakhovka hydro power dam in the Ukraine suffered a catastrophic breach on 6 June 2023 as a result of a Russian missile attack during conflict across the region. In response to this, the UK Foreign and Commonwealth Development Office commissioned the UK Centre for Ecology and Hydrology (UKCEH) and HR Wallingford to conduct a rapid remote, desk-based environmental risk assessment of the flood event and potential impacts on the surrounding environment.
With this area in southern Ukraine in a warzone, cutting-edge technologies were utilised from 12 – 26 June 2023 to carry out the first independent assessment of the impacts within weeks of the dam being breached. Environmental assessments have previously taken place only after a war when it is safe for scientists to carry out in-depth field studies, but this has limited the scope of targeted biodiversity restoration within post-conflict recovery planning. Revolutionising such response, the Kakhovka study combined hydrological and digital modelling with satellite imagery and a study of data on the region’s ecology. This enabled the identification of protected habitats and species likely to be impacted by the breach, setting a precedent for early action in future conflicts.
Professor Bryan Spears of UKCEH hoped the assessment would provide a baseline against which to assess biodiversity and habitat impacts and recovery related to the breach. He also stressed the importance of the wider scientific community being able to fully scrutinise these results and all other assessments, thus allowing biodiversity restoration to be incorporated within post-conflict recovery planning at an early stage.
The main objectives of this work were to:
- Assess the flood hydrology, hydraulics and sediment transport following the dam breach.
- Conduct a GIS-based assessment to quantify impacts across key categories (e.g. extent of protected ecosystems, potential pollution sources flooded, proportions of land-use types impacted etc.).
- Classify hazards informing the development and application of a plausible risk assessment approach across species, habitats and river basin scales.
- Identify potential issues of concern that warrant further assessment beyond the timescales of this project.
The report’s key findings found that around 83,000 hectares of land, an area the size of Kyiv, was flooded downstream of the dam. The discharge of water was 30,000 m3/sec immediately after the breach, compared to a daily average of 2,600m3/sec.
As the Kakhovka Reservoir was almost completely emptied, thousands of fish were washed out or stranded. This included an estimated 28,000 crucian carp, totalling 95,000 tonnes with an estimated commercial value of US $108 million. Such flooding in June was also highly likely to have disrupted the life cycles of many freshwater and terrestrial species, including the Dnipro sturgeon and the downstream hatcheries established to support its conservation, as well as other migratory aquatic species. For terrestrial species, direct loss or damage of nests and offspring will have occurred, affecting birds nesting on the ground, (eg little gull, little bustard) or in emergent vegetation. These breeds in the affected area are European Red-listed species, classified as “near threatened” or “vulnerable”.
There were more than 1000 potential sources of pollution from flooded sites, including wastewater treatment works, petrol stations, landfills and industrial sites. Historical pollutants contained within reservoir bed sediments – potentially including mine waste and radioactive substances – along with sediment containing pollutants from the sources above would have been dispersed across the aforementioned habitats and into the coastal ecosystems of the Black Sea Biosphere Reserve. This reserve is home to bottlenose dolphin, harbour porpoise, Pontic or Black Sea shad, otters, the Stepp polecat, and the critically endangered slender-billed curlew, numbers of which globally are thought to be less than 50 individuals. The Dnipro delta is also important as a staging post for migratory and breeding birds including the near threatened, red-breasted goose.
As UKCEH and HR Wallingford acknowledge, the impacts of the dam breach on many of these species is difficult to determine without on-the-ground surveillance.
Emma Brown, Technical Director at HR Wallingford, added: “I am very proud of the work we’ve done with UKCEH to assess the environmental impacts of the Kakhovka Dam breach. Combining our expertise in dam breach modelling, hydrology and earth observation with UKCEH’s expert biodiversity knowledge enabled the team to produce a detailed report in just 16 days, which I hope will be instrumental in helping with recovery efforts in the region.”
The report, which informed a wider report by the UN Environment Programme, also identified potential long-term effects on the environment, human health and economies. It said the flooding would have worsened water infrastructure and quality, affecting drinking water supply and irrigation for agriculture.
The authors made several recommendations for future action including an assessment of the sources of radioactive and munitions waste, and their movement down the Dnipro River to the Black Sea. This would support clean-up efforts, reduce the risks to human health associated with eating contaminated fish, shellfish and crops and safeguard a key global grain shipping route if there are unexploded arms in the area.
“This significant work undertaken in a timely way using cutting-edge technologies highlights the importance of using science from organisations to inform humanitarian and environmental response to disasters and emergencies across the globe,” Professor Harry Dixon, Associate Director of International Research and Development, UKCEH, commented.
Second attack
In March 2024 the Dnipro hydroelectric power plant in Zaporizhzhia, Ukraine, also fell victim to a missile attack, delivering another blow to the country’s energy infrastructure.
According to Ukrhydroenergo, Ukraine’s state-owned hydropower company, the assailants targeted the hydraulic structures and dam, posing a significant threat of an environmental disaster. Emergency services and power engineers worked tirelessly to contain the damage caused by the air strikes and despite the severity of the situation, there was no imminent danger of a breach.
Dnipro is the most powerful station in the Dnipro cascade and plays an important role in ensuring the stability of Ukraine’s power system. Ihor Syrota, CEO of Ukrhydroenergo underscored the immense challenges ahead, emphasising the urgency of implementing swift and coordinated efforts to mitigate the crisis with support from international partners.
“Given the scale of the destruction, we must do everything possible to prepare for the upcoming winter. Restoring what was destroyed in a moment will take years and cost billions of hryvnias. We need increased support from the international community,” he stated.
Ukrhydroenergo undertook all feasible measures to minimise the impact on the country’s energy system, including mobilising resources, rapidly repairing the damaged facilities, and enhancing security protocols. In the context of the power system and two recent attacks on hydropower dams, Ukraine lost more than 1000MW of regulating capacity.
In response to the attacks, Eddie Rich, CEO of the International Hydropower Association, expressed deep concern and condemnation, emphasising the need to safeguard hydroelectric assets from being weaponised for destructive purposes.
“We are deeply concerned to learn of the recent missile attacks on the Dnipro hydropower plant in Ukraine. Our thoughts and prayers for safety and peace go out to everyone affected,” Rich said. “The International Hydropower Association condemns in the strongest possible terms any action that seeks to weaponise hydroelectric assets that are designed to provide clean, reliable and affordable energy and water supply for all.”
In March 2024 the European Investment Bank signed a Memorandum of Understanding (MoU) with Ukrhydroenergo, on enhanced support for its hydropower facilities. EIB will provide further support as a key implementing partner of the European Union’s €50billion Ukraine Facility and the EIB’s EU for Ukraine Fund.
Ukrainian Prime Minister Denys Shmyhal said: “We are grateful for the EIB’s unwavering support and significant contribution to Ukraine’s energy security. Due to the actions of Russian terrorists, Ukraine’s hydropower has lost about 2500MW of capacity. With the help of our partners we were able to already restore more than 1500MW. The restoration continues and will accelerate. We value the active role and support that EIB provides for the projects in key sectors of the Ukrainian economy.”
EIB Vice-President Teresa Czerwińska, in charge of the Bank’s operations in Ukraine, added: “By focusing on critical infrastructure projects, particularly in the energy sector, we aim not just to meet immediate recovery needs but also to lay a strong foundation for Ukraine’s sustainable development. We stand ready to support Ukraine’s main hydropower generation company, Ukrhydrenergo, to strengthen Ukraine’s energy security at a time of repeated attacks on civil power infrastructure by Russia.”
