Water is one of the most vital resources on Earth and plays a crucial role in sustaining life. With the rapid increase in population and urbanization, the demand for water has been increasing exponentially, leading to an immense pressure on the existing water resources. In this context, the assessment, modelling, and management of water resources have become crucial to ensure sustainable development. This book, "Water Resources Assessment, Modelling and Management," is a collection of 101 articles that delve into various topics related to water resources. It covers various aspects related to surface water, groundwater, surface water modelling, groundwater modelling, management of water resources, challenges and strategies, advanced techniques in water resources, thrust areas. The book provides a special emphasis on water resources issues and management in India, which is crucial due to the significant water-related challenges faced by the country. The articles in the book offer a broad overview of the latest techniques, tools, and strategies used in the assessment, modelling, and management of water resources. Each article is concise, with a length of around three pages, and provides a brief yet informative summary of the respective topic. The aim of the book is to provide readers with a quick and accessible overview of each topic, without delving too deeply into technical details or using equations. To keep the content straightforward and easy to understand, the articles do not contain equations. However, readers who wish to explore a topic in more depth are encouraged to consult other relevant books and resources, where they can find more comprehensive information and mathematical formulations. The book aims to be a valuable resource for water resources professionals, researchers, and students who are interested in understanding the challenges associated with water resources and the strategies for their management. It covers a wide range of topics, including the latest techniques and tools used in water resources management, and the impact of climate change on water resources. Overall, the book provides a comprehensive overview of the current state of knowledge and practice in the assessment, modelling, and management of water resources. The book is expected to serve as a useful reference for anyone interested in this important and timely topic.