Dear Colleagues,

Many people still hold stubbornly to the belief that nature’s resources are unbounded and that the world’s ecosystems are merely too large to be significantly impacted by the mere actions of humans. However, environmental catastrophes (e.g., extended droughts) have occurred throughout human history, even causing the collapse of whole civilizations (e.g., Easter Island, Mayas, Sumerians, Nazca, Ancient Megafauna of Australia, Anasazi, and probably Minoans). Indeed, there are current estimates that a quarter of the world’s population or a third of the population in developing countries live in areas suffering from severe water scarcity. A particular concern is the declining water tables in the arid and semiarid regions of Asia, the Middle East, and the Mediterranean basin.

Based on the facts that fresh water supplies on Earth will remain the same, they are unevenly distributed, and, as urbanization is increasing at high rates worldwide, water availability (in m³/inh.), especially in urban areas, will become a critical issue in future megacities. At the same time, it should be considered that transporting surface water over long distances from in-land to coastal areas, treating it, using it for potable purposes, and then retreating and discharging it back into the sea is not a sustainable manner of water management. Similarly, the further overexploitation of groundwater seriously impacts the environment (e.g., sea level rise). Finally, climate fluctuations may adversely affect water resources worldwide through warming, shifts in precipitation patterns, and extreme weather events (droughts, heat waves, floods). In such cases,  expanding the reuse of marginal waters should be implemented—particularly in coastal urban areas, to produce water for all uses. Additionally, this practice complies with the circular economy concept and can help us cope with climate change and/or variability. However, expanding water reuse is not straightforward, as several public health and environmental issues still need to be addressed. Of particular importance are the issues arising from the spread of specific emerging and/or other pollutants, such as disinfection byproducts and pharmaceuticals, as well as antimicrobial resistance, which can harm the environmental quality and threaten food safety. These factors are highly related to economic balance and public acceptability. It is apparent that we need advances in wastewater treatment and regulatory frameworks toward a more sophisticated and economically viable wastewater reuse management.

This Special Issue of Water entitled “Water Scarcity: From Ancient to Modern Times and the Future” aims to address all the above aspects by seeking relevant research and review manuscripts. More analytically, the scope of this SI could include:

• The collapse of old civilizations: The role of drought;
• Urbanization and water supply;
• The history of water science and technology;
• Climate change variability and water quality and supply;
• Water supply under water scarcity;
• Irrigation and drainage under water scarcity;
• Water use efficiency issues;
• Water scarcity and land use: environmental and climate impacts;
• Water scarcity, food production, and economy impacts;
• Water scarcity and energy;
• Water scarcity and soil and water resources management;
• Water reuse;
• The use of marginal waters;
• Water reuse planning, policy, monitoring requirements, and standards/criteria;
• Water supply and wastewater treatment and reuse in future cities;
• Water scarcity, water reuse, and circular economy;
• Water and wastewater policies.

Dr. Vasileios Tzanakakis
Prof. Dr. Giovanni De Feo
Dr. Andreas Angelakis
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• water supply
• water scarcity
• water reuse
• water policy
• water management