Danube reached record low levels in some places this summer, while similar problems appeared on other large European rivers. The consequences are already being felt in navigation, energy, agriculture and river ecosystems.
This year's drought raises a more important question: will low summer water levels become more frequent due to climate change?
At the entrance of the Danube from Croatia to Serbia, near Bezdan, on August 5, a depth of only 169 centimeters was measured, the smallest since measurements have been taken at that location.
With high temperatures, long-term absence of precipitation and changes in the snow cover of the Alps, large parts of the Danube basin are left without their usual water supplies. The problem is not just this year's water level, if similar extremes are repeated, from navigation and electricity generation to agriculture and water supply, an increasing number of systems will have to adapt to new hydrological conditions.
Where did the Danube disappear to in Serbia?
Although a large number of rivers had low water levels this summer, the Danube stands out in particular, which was in the worst condition in Vojvodina throughout its course. The reason for this is the lack of precipitation in the basin of the Danube, Sava and Tisza rivers. The Sava is the largest tributary of the Danube in terms of water volume, and the Tisa in terms of basin area.
Sava and Tisza, as well as the Danube, are at the limit of the historical minimum. Jasna Plavšić, full professor of the Faculty of Civil Engineering in Belgrade, points out that as an important factor.
AP Photo/Darko VojinovicDanube with low water level
"Given that there is a lack of precipitation in the whole of Europe this summer, as well as that there was not much snow in the winter, it can be said that this year's record low levels of large rivers represent an exceptional extreme. This hydrological extreme is a combined consequence of the aforementioned and current weather conditions, i.e. long-term high temperature and precipitation deficit, but also the impact of long-term trends in global warming, i.e. climate change," says Plavšić.
The phenomenon that is currently active with the Danube and other European rivers is called hydrological drought, explains Plavšić for "Vreme".
"Low-water periods such as this represent long-term phenomena caused by a lack of precipitation. If there is not enough precipitation for a long period, the water supplies in the river basins are depleted and the rivers flow less and less. In this sense, this lower extreme is completely different in character from floods as the upper extreme, because floods occur relatively suddenly, and compared to droughts, they pass quickly. It takes some time to exhaust the water reserves in the basins, but it also takes time to they are compensated when precipitation occurs. That's why hydrological droughts lag behind meteorological droughts, that is, the lack of precipitation," explains the professor of the Faculty of Civil Engineering.
Problems created by the Danube
The low water level of the Danube creates several types of problems. It complicates water traffic, which was not suspended, but ships moved with less cargo, while tourist ships canceled or shortened tours.
The trade and the flow of oil derivatives are threatened by the very difficulty of navigation. This is particularly important because the Danube is an important channel for the flow of oil derivatives from the Black Sea region, which from the port of Constanta go all over Europe upstream of the Danube.
Rivers also become an incubator for various types of bacteria, so experts do not advise swimming in rivers. The water was therefore of a lower quality, when it comes to drinking water, while fishing associations do not advise the consumption of fish from rivers.
The living world in the rivers is not threatened only because of the lack of water in the rivers, but also because of a number of other factors, says Professor Plavšić.
"The living world is also threatened by lower water quality - higher water temperature, less oxygen in the water, less possibility of diluting polluting substances that reach the rivers. Cutting off backwaters is problematic for the movement and reproduction of fish, and the same is true for the fauna in wetlands next to rivers that dry up in the rainless period," says our interlocutor.
In Europe, the Danube is also important in terms of energy. Nuclear and thermal power plants are located on that river, which operate on a reduced scale due to the low water level. The Hungarian nuclear power plant PAKŠ operates at minimum capacity, due to the limited amount of water required for cooling. Of the existing four reactors, only one is operating, which is the first time in 44 years that the Hungarian giant has been reduced to a minimum, reports Reuters.
Photo: Daniel KissPAKŠ nuclear power plant during the 2026 drought.
Also, hydroelectric power plants operate at reduced capacity due to the lack of water. At the end of July, Đerdap was operating with a water flow of 1.600 cubic meters per second, which is far lower than the minimum biological limit of 2.350 cubic meters per second. During July, the production of electricity in hydroelectric power plants reached a daily minimum of 407 megawatt hours, only a fifth of the highest production of 2.147 megawatt hours, according to the portal. Energyflux.
The slowdown of energy plants directly affects the production of electricity, and many European countries call for rational consumption. This automatically triggers a higher demand for electricity, which is less in such periods, and therefore the price is higher.
Farmers who depend on irrigation due to droughts have found themselves in a problem because the level of the Danube has dropped. However, the water in the irrigation canals was in acceptable amounts, noted the official authorities. In addition to the low water level of the rivers, agriculture is also threatened by the decrease in air humidity, which has threatened the crops of corn, soybeans and sugar beets.
Plavšić reminds that the problem with the low water level of the rivers can threaten the water supply, especially on smaller rivers.
"It must be noted that the water supply was significantly more threatened in 2024, when over 60 places in Serbia had restrictions and when the dry and warm period lasted for almost three months. This year, it seems that there are fewer restrictions, which means that the same or similar weather conditions can lead to a different level of risk in the water supply depending on other factors, such as, for example, the state of water supplies in storage lakes and in underground waters," reminds Plavšić.
The future of the Danube
Projections for the Danube Basin indicate that future hydropower production could decline, especially during the summer months, due to changes in water availability.
The ecosystem is in crisis because the Danube has dropped to the minimum necessary for animal and plant life. Climate projections indicate that the periods during which ecological needs for water will not be met could increase. The average water temperature could in the period 2021-2050. increase by about 1,7 degrees compared to the period 1971-2000, while an increase of about four degrees or more is projected for the summer months. An increase in the number of days with extremely high water temperature, above 28 degrees, is also expected.
In the warmer and drier parts of the Danube basin, a greater need for irrigation water is expected due to a decrease in summer precipitation. The southern and eastern parts of the basin, including Serbia, are expected to be among the areas that will be particularly exposed to droughts and water shortages.
Projections show that the problem may not only be the total amount of water, but also its distribution throughout the year. Summer precipitation in the Carpathian region could, according to projections, decrease by about 20 percent, while winter precipitation could increase by 5 to 20 percent by 2100. At the same time, the period with snow cover is expected to shorten.
PHOTO: TANJUGLow water level of the Danube
In the southern and eastern parts of the Danube basin, a decrease in the total annual river flow is predicted, while the western and northern parts could have a different trend. For dry months, projections to 2050 show average flow changes ranging from a four percent increase to a 19 percent decrease, depending on the area.
This means that the future problem may not simply be less water, but a changed hydrological regime – less reliable water availability in the summer, with potentially higher flows and a greater risk of winter flooding.
If low water levels become more frequent, the question is no longer just how to survive a dry year, but how to adapt infrastructure and the economy to conditions in which low summer water levels are more frequent.
How can problems be solved?
The Romanians are trying to divert the Danube with controlled explosions near the Cernavoda nuclear power plant, in order to ensure sufficient flow to cool the plant. They detonate stone barriers and sink barges full of stones to divert the flow of the Danube closer to the power plant. However, as the Danube is still at a low level, the Romanians decided to temporarily shut down both nuclear reactors.
The solution for agriculture in some regions, where nature allows, such as the south of Serbia, i.e. the Leskovac region, is the use of underground water for irrigation, reports Deutsche says.
Droughts are a complex problem and a great deal of coordination is needed to solve the problem. Coordination is needed at the level of the entire river basin, which, in the example of the Danube, includes 19 countries. Plavšić reminds that measures have been initiated in Serbia to solve the problem of floods as the opposite extreme, while no one has dealt systematically with the problem of droughts.
"The fight against such extremes should and must be systemic. In other words, we should have plans for managing water resources, as well as plans for adapting to climate and other changes in various sectors. These plans must be preceded by serious assessments of climate and other dangers and risks. Without knowing the real threat, effective and sustainable measures cannot be recommended. In Serbia, a flood risk assessment has been carried out and the development of a flood risk management plan has been started, but nothing has been done for droughts yet. nothing", concludes Plavšić.
Only in August: Save three thousand dinars on the annual subscription to the digital edition of "Vremena"! Take advantage of the discount here and support independent journalism.
