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.

The spectacular industrial and economic development of the twentieth century was achieved at a considerable environmental cost. The increasingly precarious position of water, the most valuable of natural resources, reflects this trend. Today we have come to realise that concepts of sustainable development need to

The city of Pittsburgh and surrounding area of southwestern Pennsylvania face complex water quality problems, due in large part to aging wastewater infrastructures that cannot handle sewer overflows and stormwater runoff, especially during wet weather. Other problems such as acid mine drainage are a legacy of the region's past coal mining, heavy industry, and manufacturing economy. Currently, water planning and management in southwestern Pennsylvania is highly fragmented; federal and state governments, 11 counties, hundreds of municipalities, and other entities all play roles, but with little coordination or cooperation. The report finds that a comprehensive, watershed-based approach is needed to effectively meet water quality standards throughout the region in the most cost-effective manner. The report outlines both technical and institutional alternatives to consider in the development and implementation of such an approach.