According to the World Health Organization (WHO), water security has been described as “when all people at all times have both physical and economic access to sufficient water to meet their daily needs, and this translates to productive and healthy life”. Globally, water is considered as a key physical resource that plays a huge role in improving the pace of general development of a country. Studies have shown that having sustainable water supply system is one way of alleviating poverty and promoting economic growth of a country. Therefore, water security is an essential aspect of livelihood in any part of the world. Considering the growing world population, water resources are significantly decreasing day by day. It has been estimated that the total world population by 2025 will have grown by additional 2.6 billion from the current population. As the population increases, so does the demand for water. Therefore, without ini¬tiative taken to solve various issues on water security in most parts of the world, it is expected in future that more than half of the current world population will lack access to safe and clean water for various daily activities.

At the World Economic Forum Annual Meeting that was held in Davos-Klosters in 2008, different business leaders set out a “Call to Action on Water”. Their main goal was to raise awareness in order to develop a better understanding of how water is associated with economic growth across a nexus of issues. This was also to make clear the water security challenges expected to be faced by 2030 especially if a business as usual approach to water management was to be maintained.

Water security challenges experienced in different parts of the world, together with an intensified severity in droughts and flood events which are mainly brought by change in climate are urgent calls for better water risks management. These include management in water shortages, water pollution, and other risks to freshwater systems (lakes, rivers, and aquifers). The main idea is to adopt an appropriate approach that will help in knowing, targeting, and managing various risks and threats of water. This book contains 10 Chapters that discuss different topics on water security locally and internationally. Some of the key topics discussed under these chapters include introduction to water security, sustainable water supply, Integrated Water Resources Management and poverty reduction, ecosystem and water quality, water pollution, water quality protection, benefits of reusing reclaimed water, harvesting and storage of rainwater, seawater desalination, and solutions to water security challenges in the world. The issue of maintenance and management of water supply systems remains one of the key aspects of ensuring that there is water security all time. That is why the concept of integrated water resource management has been discussed widely in this book. Another key aspect that has been discussed entirely in this book is access to adequate safe and clean water for all. This is because it is a fundamental human right to have access to clean and safe water for all. The collection efforts that was put in preparation of this book may not serve as a complete picture of the myriad dimensions of water security, but they reflect some of the difficulties and tensions faced by science in accommodating the idea of water security (based on principles, perspectives, and practice), especially while navigating various economic, political, social, and environmental demand and concerns for sometimes scarce and usually highly variable water resource.