How to Build Pedestrian Footbridges over Mountain Rivers Prone to Dynamic Flood Phenomena?

The paper analyses the impact of the September 2024 flood in the Kłodzko Valley (Poland), which exceeded previous extreme events from 1997 and 2010. The flood was caused by heavy rainfall from the Genoa low, leading to record-breaking water levels in local rivers, including the Nysa Kłodzka and Biała Lądecka. Many bridges and footbridges suffered severe damage due to structural weaknesses and foundation erosion. Light steel structures were particularly vulnerable, swept away by the flood wave. Historical stone masonry abutments also failed under water flow. The study highlights the need for improved design strategies, emphasising deep foundations, rigid frame structures, and flood-resistant materials. It also proposes new guidelines for constructing bridges in flood-prone areas, considering both hydraulic and structural resilience. The findings indicate that rebuilding damaged structures without modifications would lead to future failures. The study underscores the importance of adapting infrastructure to extreme hydrological events and suggests implementing retention reservoirs as a long-term solution.