Water: The Environmental, Technological, and Societal Complexity of a Simple Substance

For such a simple substance, water plays a remarkable variety of critical roles at scales ranging from molecular to global. Water is essential to life, constituting roughly 60% of our bodies and is a dominant feature of our planet, covering over 70% of its surface. Because of the importance of water to society - for purposes ranging from consumption and sanitation to irrigation, navigation, and energy production - water management has been a principal responsibility of civil society throughout history. Water infrastructure represents a major investment on the part of society and has dramatically changed the extent and function of natural water bodies and watercourses. With the current megatrends of population growth, urbanization and changing consumption patterns (especially to more meat-based diets), demands, and pressures on water resources are increasing. Meeting the direct needs of societies and, simultaneously, maintaining aquatic ecosystem structure and function will require collaboration, cooperation, and the open sharing of knowledge and experience among water researchers (from the natural, social, and engineering sciences), professionals (from the public and private sectors) engaged in management and regulation of water supply and resources and civil society organizations that seek to promote sustainable water management and protection of aquatic ecosystems.