This Book includes selected papers that has been published in the Water journal Special Issue (SI) on Water Supply and Water Scarcity. Moreover, an overview of the SI is included. The papers selected for publication in the SI include review and research papers on water history, on water management issues under water scarcity regimes, on rainwater harvesting, on water quality and degradation, and on climatic variability impacts on water resources. Overall, the issue identify and highlight the main challenges in water sector, and particularly in management and protection of water resources and in use of alternative (non-conventional) water resources, especially in areas with demographic change and climate vulnerability in order to achieve sustainable and secure water supply. Furthermore, general guidelines and possible solutions for an improved and sophisticated water management system are proposed and discussed, such as the adoption of advanced technological solutions and practices that improve water-use efficiency and the use of alternative water resources, to address the growing environmental and health issues and to reduce the emerging conflicts among water users.

Accounting for approximately 99% of all liquid freshwater on Earth, groundwater has the potential to provide societies with tremendous social, economic and environmental benefits and opportunities. However, this natural resource is often poorly understood, and consequently undervalued, mismanaged and even abused. In spite of its overall abundance, groundwater remains vulnerable to over-exploitation and pollution, both of which can have devastating effects on the resource and its availability. In the context of growing water scarcity across many parts of the world, the enormous potential of groundwater and the need to manage it sustainably can no longer be overlooked. The 2022 edition of The United Nations World Water Development Report describes the challenges and opportunities associated with the development, management and governance of groundwater across the world.

This book is the result of a joint research effort led by the U.S. National Academy of Sciences and involving the Royal Scientific Society of Jordan, the Israel Academy of Sciences and Humanities, and the Palestine Health Council. It discusses opportunities for enhancement of water supplies and avoidance of overexploitation of water resources in the Middle East. Based on the concept that ecosystem goods and services are essential to maintaining water quality and quantity, the book emphasizes conservation, improved use of current technologies, and water management approaches that are compatible with environmental quality.