Poland’s Institute of Meteorology and Water Management (IMGW) has recorded almost 400 hydrological monitoring stations across the country where river flows have fallen below the long-term mean low flow level. In August, another record-low water level was registered on the Vistula in Warsaw. The capital is not at risk of interruptions to water or heat supplies, but increasingly low river flows are affecting navigation, water management and infrastructure. Warsaw is expanding small-scale water retention and green-blue infrastructure to improve its resilience to both drought and sudden flooding.
“Low water levels on the Vistula are a clear indicator of climate change. They are tangible and visible. The past three seasons are clear evidence that less and less water is flowing through the river. This is partly because the Vistula has a snow-and-rain-fed regime,” Jan Piotrowski, the Mayor of Warsaw’s representative for the Vistula River, told the Newseria news agency.
“The last winter was snowy, but temperatures remained below freezing for a long time, so the snow did not melt and the soil did not absorb the water. As a result, there was little local retention. Then, in spring, the snow melted very quickly, leaving little time for that water to gradually enter the river system.”
On 14 August, IMGW reported that 392 hydrological stations across Poland were recording flows below the long-term mean low flow, known as SNQ.
At the peak of the summer of 2025, 314 hydrological stations in Poland recorded flows below SNQ, representing 30% of all monitoring stations. By comparison, the maximum was 308 stations in 2024 and 200 in 2023. In mid-August, 89 hydrological drought warnings were in force.
According to IMGW’s Climate of Poland 2025 report, total annual precipitation last year amounted to 546 mm, equivalent to 89.31% of the long-term norm. IMGW classified 2025 as a dry year.
The average temperature in Poland reached 9.5°C, or 0.8°C above the 1991–2020 reference period. Since 1951, Poland’s annual average temperature has increased by approximately 2.4°C.
In September 2025, the Vistula at the Warszawa-Bulwary monitoring station reached a historic low. On 2 September, the water level stood at 4 cm according to the gauge scale used at the time, with a flow of approximately 154 cubic metres per second. Under the current gauge scale, that figure corresponds to 104 cm.
On 7 August 2026, IMGW reported another record, with the water level at Warszawa-Bulwary falling to 102 cm.
“The river level is very important to us, but flow rates are even more significant. They tell us how many cubic metres of water are passing through the river at any given moment. At present, the figure is around 160 cubic metres per second, so we are still some way from the most dramatic situations seen in the 1920s and 1940s, when flows were around 80 and 120 cubic metres per second,” Piotrowski explained.
“Nevertheless, nature is telling us that this is a risk we have to take into account. At the same time, major rises in water levels can also occur.”
The last major flood surge on the Vistula occurred in 2010, when the water level exceeded the alarm threshold and reached 780 cm.
“At the moment, the gauge shows around 104 cm, but it can also reach 704 or 804 cm, because Warsaw is broadly prepared for levels of that magnitude. Just imagine the scale of the difference. Where we are standing now – on the embankment protecting the left-bank part of Warsaw – the river could naturally rise almost to this height,” the Mayor’s representative for the Vistula said.
He stresses that Warsaw’s hydrotechnical infrastructure is designed to cope with both extremes, including the current exceptionally low water levels. In the longer term, however, low flows could affect facilities such as the Siekierki combined heat and power plant, which uses water drawn from the Vistula to cool technological equipment.
In the European Water Resilience Strategy adopted in mid-2025, the European Commission noted that 17% of water resources used in the EU are consumed by the energy sector. The EU therefore plans initiatives aimed at identifying accessible and viable dry-cooling technologies.
“At present, there is no situation in which we face blackouts or shortages of heating, but we have to think about the future. The Vistula should be a warning signal for us. We need to take into account what is happening to the river if we want to protect not only its natural environment but also quality of life in the city,” Piotrowski said.
Low river levels are also affecting recreation in Warsaw. Over recent years, river cruises have become an important part of the capital’s tourism offer.
Last year, almost 40,000 passengers took part in sightseeing cruises and themed events on the Vistula aboard vessels operated by Krypa.pl.
“Our research shows that more than 30% of residents now spend their weekends actively. They do not simply come to the river to sit by the water; they also want to go kayaking or take a recreational cruise. Ferries are a very characteristic feature of the Warsaw section of the Vistula,” Piotrowski said.
“Unfortunately, this year they have been operating only intermittently, partly because the vessels are relatively old and have a deep draught. If the river gauge shows 104 cm, it is clear that such a vessel may not be able to operate because it could run aground on a sandbank or rocky shoal. We can already see that there are fewer cruises, and they are taking place over shorter sections of the river.”
Warsaw’s Municipal Water and Sewerage Company, MPWiK, stresses that the city’s water supply remains stable because it relies on two sources: the Vistula, which provides around 70% of the supply, and Lake Zegrze.
Although drought-related interruptions to drinking water supplies are not currently expected, the exceptionally low river levels recorded particularly during the summer remain a cause for concern.
“These figures tell us very clearly that we need to think about how we use water. There may simply not be any more of it. We cannot pour additional water into the Vistula,” Piotrowski said.
“MPWiK takes water from the Vistula, which is filtered and then delivered to our taps. If we use it sustainably, we can at least hope that our actions will have some impact on what happens next.”
MPWiK experts recommend rational use of water resources. Their suggestions include turning off the tap while brushing teeth, replacing baths with short showers, installing tap aerators, collecting rainwater for watering plants, and using water-efficient washing machines and dishwashers.
According to Piotrowski, sustainable water use must also apply to the city itself, including the maintenance of urban greenery such as parks, green spaces and roadside vegetation.
“Warsaw is one of the greenest cities in Europe, but maintaining that greenery also requires enormous work from specialists selecting appropriate plant species that need relatively little water. Irrigation schedules are adjusted depending on periods of lower rainfall and, consequently, lower water levels in the Vistula,” he said.
“Education, small-scale retention projects and green-blue infrastructure are also part of our everyday work. We exchange experience with other cities, including Kraków, Gdańsk and Wrocław. The rivers and water resources in those cities have different characteristics, but certain mechanisms and solutions can still provide inspiration and be shared.”
At the beginning of September, Warsaw will host the international United by Rivers conference, providing an opportunity to discuss how river cities should develop and how they can reconcile environmental protection with residents’ needs and the development of modern metropolitan areas.
According to the Warsaw Greenery Authority, the ability to retain water is crucial both during droughts and during episodes of intense rainfall.
So-called blue infrastructure includes solutions that allow rainwater to soak into the ground where it falls, circulate locally and support ecosystems instead of immediately flowing into sewers or rivers.
Examples include rain gardens, retention reservoirs, green roofs and tram tracks, infiltration basins, natural watercourses and wetlands, and linear parks. The city stresses that such infrastructure is becoming a key element of climate resilience.
As part of the Warsaw Rushes programme, the city is also focusing on restoring natural aquatic ecosystems within the urban environment. These systems are intended to retain rainwater and release it gradually back into the environment while also improving the quality of surface water.
Removing impermeable concrete surfaces from public spaces and planting more trees are also important elements of the city’s strategy.
