"Hydraulic Structures: Probabilistic Approaches to Maintenance" is an introduction to the field of probability theory and its applications in engineering. This book provides an overview of probabilistic methods at an introductory level including the probability of sets, arithmetic operations with random variables, probabilistic reliability calculations, and risky decision evaluation, as they apply to maintenance of hydraulic structures. Major benefits of the book include conveying to the reader the basic knowledge of a collection of probabilistic methods; creating a deep understanding of these methods by leading the reader through numerous derivations of formulas; helping the reader recognize that probabilistic methods are superior to traditional deterministic analysis; and instilling appreciation of these methods by presenting some very powerful probability laws and functions, which provide insight into the apparent chaos of the world of random numbers. This book is a useful tool for those in the hydraulic structures maintenance community, including hydraulic engineers, because it incorporates probabilistic methods into mainstream engineering.