On 6 June 2023, Russian forces blew up the dam of the Kakhovka Hydroelectric Power Plant in Ukraine’s Kherson region. The explosion unleashed catastrophic flooding across 620 square kilometres, inundating parts of Kherson, Mykolaiv, Dnipropetrovsk and Zaporizhzhia. The Kakhovka disaster sparked international outcry and raised alarm among scientists around the world — not least because there are more than 50,000 large reservoirs globally, many of them ageing and increasingly at risk. In response, a team of 29 scientists launched a wide-ranging investigation. Their findings, published in Science in March 2025 under the title Environmental effects of the Kakhovka Dam destruction by warfare in Ukraine, paint a grim picture: the fallout from the dam’s destruction will be felt for decades — perhaps even centuries.
Nearly two years on from one of the world’s worst man-made environmental disasters, The Ukrainian Week spoke with Mykhailo Yatsiuk, director of the Institute of Water Problems and Land Reclamation at Ukraine’s National Academy of Agrarian Sciences, and Valerii Khilchevskyi, professor at the Faculty of Geography at Taras Shevchenko National University of Kyiv. We discussed the environmental toll across the region, the looming threat of desertification around the drained reservoir, and whether the dam can — or even should — be rebuilt.
— Looking at the bigger picture, what does the Kakhovka Reservoir area look like now?
— Mykhailo Yatsiuk (M.Y.): Right now, several large lakes have formed where the Kakhovka Reservoir once was — some still loosely connected to the main channel of the Dnipro, others entirely cut off. There are also dozens of smaller lakes and hundreds of shallow pools scattered across the area. And the landscape is still changing: the Dnipro is carving out new paths through erosion, creating meanders, islands and shifting shorelines. To give you a sense of scale — on 6 June 2023, the Kakhovka Reservoir covered 2,065 square kilometres. Today, that’s down to just 261.1. That’s only 12.7% of its original size. In effect, the reservoir no longer exists. What remains is a vast, exposed basin contaminated with hazardous bottom sediments.
— What exactly are these bottom sediments, and what kind of danger do they pose?
— Valerii Khilchevskyi (V.Kh.): These are layers of toxic substances — heavy metals like nickel, cadmium, lead, zinc, phosphorus and more. Working alongside 29 scientists from Germany, the US, the Netherlands, Belgium, Turkey, Argentina, Ukraine and other countries, we found that around 83,000 tonnes of these pollutants are trapped in the reservoir bed’s sediments, which are roughly 1.5 metres thick. For years, they’d been more or less sealed off — contained underwater. But the dam’s destruction exposed them. The danger is real: heavy metals don’t break down. Once they enter the human body, they can harm the nervous system, disrupt hormones, even lead to birth defects. Now that the sediments are uncovered, these toxic elements can start entering the food chain. Flooding, rainwater runoff, wind erosion, even natural biological processes could further mobilise them, spreading the contamination over time.
— And where did the toxic pollutants — the heavy metals and other substances — in the Kakhovka Reservoir come from?
— V.Kh.: On the reservoir’s right bank, in its central section, are the cities of Nikopol and Marhanets. Further upstream lies the Dnipro Reservoir, flanked by the industrial hubs of Dnipro, Zaporizhzhia and Kamianske. These cities are home to a vast number of industrial plants — many of which discharged pollutants, including heavy metals, into the water. Much of that contamination flowed downstream and settled in the Kakhovka Reservoir. Over time, this resulted in a thick layer of toxic silt — up to a metre deep in most areas, and as much as a metre and a half in some places — rich in hazardous chemical substances.
— Given all these negative factors, how have the water resources of the Mykolaiv, Kherson, Zaporizhzhia and Dnipropetrovsk regions been affected overall — and what has this meant for local communities?
— M.Y.: The consequences of the attack on the Kakhovka Hydroelectric Power Plant have triggered a series of environmental catastrophes — from the drying up of the reservoir bed and flooding of nearby areas to the collapse of the irrigation systems in Kherson and Zaporizhzhia. One of the most urgent problems is the disruption of drinking water supplies, along with water for domestic and industrial use — in short, a severe shortage. The destruction of the dam knocked out pumping stations and eliminated the ability to store water or regulate flow in what is already Ukraine’s most water-scarce region: the Lower Dnipro sub-basin. As a result, during dry spells, there’s now no way to ensure a reliable water supply at the scale that’s needed.
Another growing concern is the excessive mineralisation of groundwater. On its own, this water isn’t suitable for drinking or domestic use — it has to be diluted with Dnipro water. However, the amount of groundwater available is extremely limited, meaning it can’t serve as a primary source of supply. On top of that, the entire discharge regime has changed dramatically. Before the dam was destroyed, groundwater naturally flowed toward the reservoir, helping to improve its quality. Now, the flow has reversed — discharging into the exposed reservoir bed and bringing with it highly mineralised groundwater and subterranean flows.
There’s also the looming threat of saltwater intrusion from the Black Sea into the lower Dnipro. This process was once kept in check by the cascade of Dnipro reservoirs. But with freshwater inflows now reduced — a trend linked to global climate change — and sea levels rising, marine waters are pushing further inland. Scientists warn the salt wedge could reach well past Mykolaiv’s water intake point.
Overall, the Kakhovka disaster has disrupted the ecological balance and set entire natural systems on a path of decline.
— You mentioned global climate change as a factor in reduced freshwater inflow. How serious is it?
— M.Y.: Extremely serious. The sharp rise in temperatures — something we’re all feeling — along with higher rates of evaporation, has thrown the climate-driven water balance of the entire Dnipro basin off-kilter. In some parts of Ukraine, freshwater reserves have dropped to the point where they threaten everyday life and the wider economy.
We’ve already seen the effects. In 2022, spring floods — once a regular feature of Ukrainian rivers — failed to materialise. Water levels were low again in 2024. That summer brought parched soils and widespread drought, which hit agricultural yields hard.
And all of this is now being compounded by the destruction of the Kakhovka dam. As we’ve discussed, it’s only intensified the downward spiral of both surface and groundwater systems in the region.
— And what impact has this had on the region’s plants and wildlife?
— V.Kh.: The dam’s destruction partially flooded the Black Sea Biosphere Reserve and the Nizhniodniprovskyi National Nature Park. While the immediate impact on biodiversity and coastal ecosystems upstream was limited, the long-term consequences are far more serious and far-reaching.
The biomass of bottom-dwelling invertebrates, especially colonies of zebra mussels — powerful natural filters — was heavily affected. Just one kilogram of these mussels can filter over a tonne of water a day, trapping pollutants in the sediments. Researchers estimate that between 200,000 and 500,000 tonnes of dead mussels now lie in the reservoir bed.
There’s also a grave threat from the die-off of other aquatic life, including large numbers of fish and animals, which is expected to become a major factor in degrading water quality along this stretch of the Dnipro in the near future.
M.Y.: The former reservoir bed is now thick with vegetation, dominated by willow, with some trees already reaching three metres tall. But the altered hydrological regime means that moisture-loving species which once thrived along the banks — such as black alder, silver birch, aspen, ash, walnut and elm — are now struggling due to a lack of water. Many are likely to die off. Their decline will not only reshape the local landscape but also contribute to the acceleration of climate change.
— The Kakhovka Reservoir was a crucial lifeline for agriculture, irrigating nearly a million hectares of land. Its destruction, combined with the collapse of irrigation systems, has led to crop losses, rising food prices, and mounting difficulties for farmers.
— M.Y.: Correct. Back in 2021, around 367,000 hectares were actually irrigated with water from the reservoir. That dropped to 192,000 hectares in 2022, and declined even further last year. Irrigation helped deliver high yields — up to 7.5–8 tonnes of winter wheat per hectare, 11–12 tonnes for maize, and as much as 90 tonnes per hectare for vegetables. Without water from the reservoir, these systems simply stopped working. In many areas, irrigated land has either shrunk drastically or been lost altogether.
The financial damage is already severe — agricultural losses in the region are estimated at 40 billion hryvnias, with the drop in grain production alone accounting for around 5 million tonnes. Flooding also triggered waterlogging, washed away nutrient-rich topsoil, and replaced it with infertile silt deposits. And now, with the water gone, vital mineral salts and microelements are leaching from the soil, increasing the risk of salinisation. And all of this is unfolding amid the backdrop of a full-scale war, which makes an already dire situation even harder to manage.
— How has the war affected life in the region, particularly when it comes to dealing with the aftermath of the hydroelectric power station’s destruction?
— V.Kh.: In short — catastrophically. The war has severely damaged or destroyed vital water infrastructure, while rivers, lakes, and reservoirs have been contaminated. Russia has weaponised water. In addition to blowing up the Kakhovka dam, its forces deliberately destroyed the Oskil Reservoir dam in the Kharkiv region in autumn 2022. Water bodies have become military flashpoints — used as natural barriers or strongholds under enemy control.
Fighting has unleashed a cascade of problems: the threat of further destruction to engineering infrastructure within irrigation and drainage systems; pollution of groundwater through runoff from non-operational industrial sites; and the uncontrolled discharge of untreated wastewater into rivers, because even where treatment plants exist, many can’t function under wartime conditions.
We’re also seeing contamination from substances used in warfare — including those with toxic or long-lasting effects — with no consistent system in place to monitor the safety of water for human use. This creates a dangerous vacuum, where people are increasingly exposed to polluted water without the means to detect or prevent the risks.
— Are there more long-term consequences still to come — say in five, ten or even fifty years — from the destruction of the Kakhovka reservoir?
— M.Y.: Absolutely. And if the reservoir isn’t restored soon, the negative effects will only accelerate. The hydrological regime of the surrounding areas — Kherson, Zaporizhzhia, Dnipropetrovsk, and even Crimea — has already changed. The Kakhovka reservoir used to feed limestone aquifers that channel water across these regions. Those reserves are still holding for now, but they’re slowly running dry — and without the reservoir, they have no way to replenish.
Just a month after the dam was blown up, groundwater levels in some areas had already dropped by five to six metres. If this continues, we could see large-scale landslides — both upstream and downstream of the dam site, stretching from Kherson to Mykolaiv.
There’s another, less obvious but no less serious consequence: rainfall. The vast water surface of the Kakhovka reservoir played a role in regulating local precipitation. Without it, the Kherson region will likely see less rain and snow in the years ahead. Fewer storms, drier soil, and worsening droughts — all of it part of the slow-moving fallout from a man-made environmental disaster.
— Is it possible that parts of the region could turn into desert?
— M.Y.: Yes. Over time, some southern areas are likely to face desertification. As the sandy bottom becomes exposed, a new desert landscape could take shape — bringing serious climate consequences with it: reduced rainfall, more frequent dust storms, and rising temperatures. Drought and parched soil could lead to failed harvests across central and southern Ukraine. On a global scale, there’s also the risk of a spike in greenhouse gas emissions from decomposing vegetation left behind in flooded zones.
— So what can be done? Is there any way to stop this from happening?
— M.Y.: Ukraine’s Scientific and Technical Council at the Ministry of Environmental Protection has already reached a consensus: the Kakhovka reservoir must be restored. At the moment, there’s no real alternative. The priority now is rebuilding the reservoir — not the hydroelectric power station. Of course, what emerges will be a very different structure, shaped by new environmental conditions and incorporating modern hydraulic engineering. But the key point is this: the mistakes of the past can’t be repeated. Every design flaw that contributed to environmental degradation last time must be addressed in the rebuild.
V. Kh.: An international team of researchers has suggested a compromise: shrinking the reservoir’s footprint by building a 50-kilometre dam. This would effectively separate the north-eastern section of the Kakhovka reservoir — historically home to the sacred lands of the Great Meadow — from the rest of the basin.
At the same time, one of our biggest challenges is limiting the spread of pollutants embedded in the reservoir bed. To tackle this, we’ve proposed constructing two temporary dams, each around 15 kilometres long, to isolate the main channel of the Dnipro from the surrounding floodplain. This, we believe, would significantly reduce the risk of contaminants leaching into the wider environment.
