Introduction to the Global Water Cycle

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.

Learning Objectives

• Complete a diagram of the life cycle of water and paraphrase how humans temporarily remove and return freshwater to the cycle.
• Define an Underground Source of Drinking Water (USDW).
• Describe the connection between watersheds, surface water and groundwater.
• Describe cases where water is temporarily withdrawn vs permanently removed from the water cycle.
• Describe various sources of household water.
• Explain important historical legislation to protect water from pollution in the United States.
• Recognize various types of private well types and maintenance issues.
• Describe various types of contamination, both human induced and natural, including contamination from methane migration.
• Describe different methods and sources of water testing, including how to establish a baseline.
• Explain different water sampling techniques for surface water, groundwater and in-home water.
• Explain the difference between primary and secondary contaminants; and give examples of contaminants representing each of the 6 broad categories for hazardous contaminants covered by U.S. National Primary Drinking Water Regulations.
• Describe trends in water use by sector in the United States since 1950.

Images: “Blue Water” by Africa Studio/Shutterstock.com