Integrating Water and Energy Resource Management: Progress and Opportunities

Integrated policy, planning, and management of water resources and energy systems can provide important opportunities. While both energy and water managers have used integrated planning approaches for decades, the broader integration of water and energy management is a relatively new and exciting policy area. Water and energy systems are interconnected in several important ways. Developed water systems provide energy (e.g. through hydropower), and they consume energy, primarily through pumping and thermal processes. Many energy systems require energy for cooling and other purposes. The focus of this paper is on energy inputs to water systems. Critical elements of water infrastructure systems and certain uses are energy intensive. Moving water over distances and elevation gains, treating and distributing it, meeting end-uses for various purposes, and collecting and treating the resulting wastewater, accounts for one of the largest uses of electrical energy in some areas. For example, estimates by the California Energy Commission indicate that 19% of the state's electricity use, and 33% of natural gas use (excluding power plants), is devoted to water use. Examples of new approaches to the integration of water and energy planning, including policy processes at the California Energy Commission, Public Utilities Commission, and Department of Water Resources are discussed. Current methodologies for accounting for embedded energy, from initial extraction through treatment, distribution, end-use, wastewater treatment and discharge, are reviewed. New approaches to institutional collaboration between energy and water management authorities and providers are also discussed.