Hydraulic structures are man-made waterworks interacting with the rainfall run-off to store and convey water, or mitigate the impact of run-off. Current approaches in hydraulic structure design tend to be conservative, not much differing from ancient designs. Modern structures are often designed based upon simplistic concepts to optimize their performances. However, today’s hydraulic engineers must embrace a number of new challenges, emerging in response to the quickly growing world population, changing climate, evolving agriculture, and growing industrial needs. Herein, new challenges are reviewed using diverse examples of air entrainment at hydraulic structures, transient turbulence during surge events in conveyance structures, and upstream fish passage at road crossings. It is argued that many technical solutions are not satisfactory, e.g. in terms of sustaining aquatic flora and fauna, fluid–structure interactions and operational constraints. Indeed, the current and emerging technical challenges in hydraulic structure design are massive for the twenty-first century hydraulic engineers. The solutions rely upon engineering innovation, excellence in hydraulic research and quality education in universities, complemented by indispensable interactions between engineers, scientists and water stakeholders.

水工建筑物是人造的水厂，与降雨径流相互作用，以存储和输送水，或减轻径流的影响。当前水工结构设计方法趋于保守，与古代设计没有太大区别。现代结构通常是基于简单的概念来设计的，以优化其性能。但是，当今的液压工程师必须应对许多新挑战，这些挑战是为应对世界人口快速增长，气候变化，农业发展和工业需求增长而做出的。在此，使用水力结构处的空气夹带，输送结构中的喘振事件期间的瞬态湍流以及道路交叉口处的上游鱼类通过的各种示例来回顾新的挑战。有人认为，许多技术解决方案都不令人满意，例如 在维持水生动植物，流体结构相互作用和运行限制方面。实际上，对于二十一世纪的液压工程师来说，水力结构设计中当前和新兴的技术挑战是巨大的。解决方案依靠工程创新，大学水力研究和质量教育方面的卓越成就，以及工程师，科学家和水资源利益相关者之间必不可少的互动来补充。