The writing of this work is a continuation of the effort that began at least a decade ago when I was a visiting professor at the Massachusetts Institute of Technology (MIT) in the USA for a year. With the help of the rich libraries of MIT and Harvard, as well as my many years of experience in teaching, research, and studying works on water management, I wrote the book "River Engineering" which was published in 2000 as student notes from the Aristotle University of Thessaloniki. Its purpose was to provide students of the Department of Civil Engineering at the Polytechnic School with a substantial aid for both their coursework and elective courses in river engineering, as well as for their professional careers after graduation from the University. The limitation of pages by the Aristotle University resulted in some subjects being completely omitted and others not being developed in detail. Emphasis was given on the one hand to the creation of scientific background so that the reader could follow future developments in this field, and on the other hand to the technological applications through which it enhanced its experience in order to be able to address the problems it undertook to solve with the corresponding scientific seriousness.
This edition, based on the previous one, has been expanded to include opinions and theories that extend to the present day. Where necessary, theory is supplemented with practical applications. Through the applications, the serious lack of knowledge of satisfactory approaches to solving almost all problems of water management becomes apparent. The reader will be surprised by the divergence, even orders of magnitude, that the results show for the same data but with different methods of approaching the solution. [...]

(from the author's preface)