Blockage at cross-drainage hydraulic structures - Advances, challenges and opportunities.

Blockage of cross-drainage hydraulic structures is a significant concern in water resources and civil engineering projects, particularly in urban areas experiencing increased debris supply. During storms or floods, debris can accumulate and restrict the flow capacity of these structures, leading to potential failures and adverse impacts on flood levels. While some argue that blockage at culverts is a non-issue, scientific research supports its significance in specific regions. However, in context of rivers and dams, blockage by Large Wood (LW) is an established issue with plenty of research in terms of its hydraulic impacts, dynamics, modeling and scouring impacts. Specifically in Australasia the Australian Rainfall and Runoff (ARR) initiative recognized the importance of studying blockage at culverts and introduced guidelines incorporating it into design and modeling. These guidelines also included post flood visual inspections of structures to understand blockage, however, this approach has been criticized by hydraulic engineers arguing that post flood visuals can not be considered as the representation of the peak floods blockage. Recently, an approach of using visual information to interpret the blockage has been adopted as a new dimension to the problem. This paper, therefore, highlights the advances, challenges, and opportunities in studying blockage, emphasizing the need for data-driven approaches and interdisciplinary collaboration. Understanding and addressing blockage are crucial for ensuring the efficient operation and longevity of hydraulic structures and promoting the resilience of infrastructure systems in the face of evolving environmental conditions.