Over the course of three days, 430 millimetres of rain fell at the weather station in Kamienica in the Kłodzko Valley — roughly equivalent to the region’s annual average rainfall. In September 2024, mountain streams turned into raging rivers within a matter of hours. Water flooded Kłodzko, Lądek-Zdrój, Stronie Śląskie and Głuchołazy, making evacuation impossible.
The disaster was driven by Storm Boris, a Genoa low-pressure system that carried moist air into Central Europe from a record-warm Mediterranean Sea. Researchers from World Weather Attribution (WWA) estimated that climate change made the rainfall around 20 percent more intense.
The rain fell on land that was not prepared to absorb it. Immediately before the downpours, Poland had been experiencing hydrological drought, while the Vistula River in Warsaw had fallen to a historic low of 20 centimetres. The parched, hardened soil acted like concrete. Instead of absorbing the water, it accelerated runoff directly into rivers and towns.
The collapse of the earth dam in Stronie Śląskie became a turning point in the debate over flood protection. Water overtopped the dam and washed away its structure. The failure showed that existing design standards, construction procedures and emergency management systems are no longer adequate for the new reality.
That reality is defined by three phenomena:
Flash floods turn weeks into minutes. The 1997 flood developed gradually, leaving time to respond and evacuate. Storm Boris showed that an extreme volume of water can fall within just a few dozen hours, triggering sudden flash floods.
The past no longer predicts the future. Existing risk maps and flood protection systems were built on statistical data from previous decades. The failure of the dam in Stronie Śląskie demonstrated that the past is no longer a reliable reference point. Infrastructure must instead be designed using dynamic models that account for continually rising global temperatures.
Hydrological whiplash has become the new normal. The rapid shift from record drought to torrential rainfall is, as reports by the Intergovernmental Panel on Climate Change (IPCC) indicate, a direct consequence of disruption to the natural water cycle.
As activists from the Polish climate movement Wschód put it: “This is not the flood of the century. This is the century of floods.” Phenomena once considered extreme are becoming the new normal, requiring urgent changes to flood-management regulations, spatial planning and urban design.
