Three years ago, the "Kakhovka" dam in southern Ukraine - one of the largest in Europe - was blown up. Moscow blames Ukraine, but journalistic investigations indicate that Russia was most likely behind its blowing up.
The dam was 240 km long and 20 km wide in places. The explosion released over 18 billion cubic meters of water, and the consequences are still incalculable today.
"Where the dam was, there are now seven-meter trees," Ukrainian biologist Oleksiy Vasilyuk told ARD. "If someone had told us back then that such a huge object could be covered with forest in such a short time, we would have answered: such a thing is impossible. But as it turned out, it clearly is."
An ecological catastrophe did not occur
Ukraine is trying to study the consequences of the catastrophe - ecological, social and economic, writes ARD correspondent Florian Kellermann. The state has engaged about 40 scientists from various research institutes for this.
The project is huge, says its head Natalia Osadzha. At the same time, she emphasizes that the worst environmental consequences expected three years ago have not occurred. One of the most frightening scenarios was related to the bottom of the former dam. Particles of heavy metals that were carried away by the water have accumulated there for decades. They were then found in the Black Sea as a kind of thin layer on the water.
Scientists feared that the wind would blow away the sediments, but this did not happen, explains Ozadzha. A positive effect was the fact that in a certain narrow place the water from the dam flowed out gradually, rather than suddenly.
Problems with water - both for drinking and irrigation
For scientists, the long-term economic and social consequences are of particular importance. Southern Ukraine has problems with water, and the "Kakhovka" dam was very important for local residents, Ozadzha points out, quoted by ARD.
"About 1.8 million people were left without drinking water after the disaster. The state took some measures to find temporary solutions - but in a number of places it was water of lower quality." The Kryvyi Rih region was most affected, where people could not rely on tap water and had to buy it.
The consequences for agriculture are even more serious. Southern Ukraine has fertile black soil, but the irrigation system has been completely destroyed, the German public media reports. Osadja adds that due to the Russian occupation in southern Ukraine, there is less arable land anyway.
There are also consequences for the "Zaporozhye" nuclear power plant, occupied by Russia. It cannot be operated without the cooling system via the dam, which is why the reactors are currently shut down.
There is no long-term solution until the war ends
For the time being, long-term solutions in the affected part of Ukraine are unclear, ARD notes. Water needs could be met from other sources, Osadzha believes, such as another dam on the Dnieper River to the northeast. But this would require investment in new canals.
The researcher suggests that the "Kakhovka" dam be restored, but on a smaller scale. For now, however, this is unthinkable in the foreseeable future, as the armies of Ukraine and Russia are stationed there on both sides of the Dnieper River, facing each other.
Author: Florian Kellermann ARD