New technologies, such as improved testing and physical modeling methods, together with numerical studies and other novel techniques, have led to many developments in the fields of hydraulic and civil engineering in recent years. This book presents proceedings from HCET 2021, the 6th International Technical Conference on Frontiers of Hydraulic and Civil Engineering Technology, held in Sanya, China, on 28 and 29 August 2021. The conference highlighted the latest advances, innovations and applications in the fields of hydraulic and civil engineering, and served as a platform to promote and celebrate interdisciplinary study. The book contains 89 papers, selected from 178 contributions and divided into 4 sections: Modern Civil Engineering; Water and Hydraulic Engineering; Environment Engineering and Sciences; and Transdisciplinary Engineering and Technology. Topics covered involve both theoretical and practical knowledge and understanding, primarily in the areas of hydraulics and water resource engineering, civil engineering, environmental engineering and sciences, transportation engineering, coastal and ocean engineering and transdisciplinary engineering and technology. The book, which presents a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among specialists in various fields, will be of interest to all academics, researchers, practitioners and policymakers seeking to understand and tackle civil and hydraulic engineering challenges by adopting appropriate, sustainable, solutions.