Culverts for Draining Torrent-Systems during Flash Foods – Current State and Ideas for Improvements

Culverts are major structures for the drainage of urban areas. In times of climate change, those structures are getting even more important, since intensity and frequency of heavy rainfalls increase - especially in the (pre)-mountainous region. In order to assess and to manage future torrents and floods, an exact determination of discharge capacity of culverts is mandatory. Due to the complex interaction between free and pressurized flow, aeration and blockage, exact determination is challenging. The resulting hydraulic system might be unstable over time, which can harm the construction of the culvert. This study summarizes those challenges and highlights practical aspects by applying analytical approaches on an exemplarily culvert. Thereby, constructive adjustments are proposed and developed, that can improve hydraulic performance of those structures.