Central Europe is likely to face another abnormally hot summer this year, which could bring intense rainfall, storms, and local flooding. Bratislava, already familiar with extreme weather, experienced severe flooding in June 2023 when the sewage system failed during a downpour, inundating streets and even the Ružinov hospital. Persistent autumn rains later that year caused significant damage across Poland, the Czech Republic, and western Slovakia, toppling thousands of trees and forcing school closures.
“We expect repeated exhausting heat waves this summer, along with strong storms with wind and torrential rain,” said Peter Bubla, spokesperson for Mayor Matúš Vallo (Team Bratislava), warning of potential flash floods and infrastructure damage.
City preparations and drainage system upgrades
The city is preparing by regularly cleaning its roughly 11,000 storm drains throughout the year and inspecting high-risk areas with cameras. In locations prone to flooding, such as underpasses on Bajkalská, Vajnorská, Račianska, and Ružinovská streets, the city has removed sediment buildup and deployed pumps to prevent future flooding. Automatic pumping systems are also in place at the Gagarinova underpass.
Despite these efforts, the city admits that complete prevention of street flooding is not always possible due to the limitations of the existing sewer infrastructure. The main goal, according to Bubla, is to remove floodwaters as quickly as possible using mobile pumping equipment and additional machinery ordered during official weather alerts.
Challenges with outdated infrastructure
The Bratislava Water Company (BVS), responsible for the sewage system, is stepping up its efforts by intensifying cleaning operations and investing in infrastructure, including work on Púchovská and Vajnorská streets and the Gaštanový canal. However, BVS stresses that the current sewer system and wastewater treatment plants were not designed to handle the sudden and massive water volumes caused by today’s torrential storms—a challenge faced by many cities across Europe.
Retention measures and public involvement
To reduce the immediate impact of heavy rain, both the city and BVS are supporting water retention strategies. These include green roofs, permeable paving, and vegetated areas that absorb rainwater. Over €322,000 in grant funding is available for schools, kindergartens, housing managers, and residents who wish to implement such projects. Applications are open until July.
The city is also integrating water retention features into new developments and renovations, replacing asphalt with water-permeable surfaces. “When assessing investment projects, we ensure that developers include permeable surfaces and sufficient greenery to retain rainfall. The less rainwater that enters the sewer system, the better,” explained Bubla.
However, he added that cooperation with private property owners remains a challenge: “Under current legislation, the city lacks direct tools to require owners to implement such measures.”
Storms already hitting harder
At the start of June 2023, the Slovak Hydrometeorological Institute (SHMÚ) issued near-daily warnings about severe storms. On June 8, the strongest storm hit Bratislava, halting public transit lines and flooding major streets such as Bajkalská, Račianska, Vajnorská, and Tomašiková.
Firefighters responded to over 30 incidents, pumping water from underpasses, basements, parking garages, and rescuing submerged cars. In Ružinov, water entered a hockey arena’s machine room and two cultural centers.
Another wave of destructive rain came in September 2024, damaging the city’s zoo, closing the popular Železná studnička park, and uprooting thousands of trees from waterlogged soil.
Heat intensifies storms, forecasts suggest more to come
Forecast models from the EU’s Copernicus program show a 70–100% likelihood of above-average temperatures in Central Europe during July and August 2025, with a 40–50% chance of lower-than-normal rainfall. Though these forecasts are regional and lack local detail, they support broader climate trends showing hotter summers and more intense weather.
The World Meteorological Organization and Copernicus noted in their 2024 State of the Climate report that Europe experienced its highest average temperatures since records began. While Eastern Europe battled heat and drought, Western countries faced widespread rain and floods.
Long heatwaves increase atmospheric moisture through evaporation and plant transpiration, which can result in more intense storms and flash floods. According to the Slovak Hydrometeorological Institute, June 2023—the month when Bratislava flooded—was either extremely dry or extremely wet across Slovakia, highlighting the growing unpredictability of summer weather.
Source: Dennik N
