This book explores the complex dynamics between surface water and groundwater, focusing on their roles, interactions, and significance in sustainable water resource management. It examines key challenges such as over-extraction, contamination, climate change impacts, and competition among users. The book also presents innovative solutions including integrated water resource management (IWRM), advanced monitoring technologies, policy reforms, and community-based approaches. With a multidisciplinary perspective, it aims to support decision-makers, researchers, and practitioners in developing resilient strategies for water conservation, equitable distribution, and long-term environmental sustainability. Ehsan Moradi holds a Doctorate in Civil Engineering and is the author of "Surface and Groundwater".