Energy provides wealth, but water is life. As precious resources, both energy and water capture the public consciousness and sit at the center of two massive sectors of the global economy. While the sectors may be perceived as two disparate entities, contemporary development and analysis focuses on the nexus between the two sectors. Increasingly, water projects are requiring more energy, and energy projects are requiring more water. Water is only one part of the larger conversation about the relationship between energy and the environment. However, an understanding of energy and its complex relationship with water provides a firm foundation for working through complex environmental issues.