The Natural Resources Defense Council (NRDC) released a report in 2004 titled “Energy Down the Drain: The Hidden Costs of California’s Water Supply.” Especially in the western part of the United States, there is a tight connection between water and energy resources, as energy is needed to reliably treat and distribute water.

Because energy and water decision-making is often siloed, water planners are not generally taking into consideration the energy-related consequences of their planning.

The full report is available here as a pdf.

The authors carefully quantified the link between water and energy for three specific case studies – San Diego County’s future supply, the Westlands Water District, and the Columbia River basin (in the the Pacific Northwest). According to the report, the Westlands Water District is one of the largest agricultural users of water in the western United States.

The overarching message of the report is that decision makers should integrate energy issues in to water planning and decision-making. It also suggests a methodology for incorporating energy impacts into water planning.

The report contains numerous interesting tidbits:

• “The more than 60,000 water systems and 15,000 wastewater systems in the United States are among the country’s largest energy consumers, using 75 billion kWh/year nationally – 3 percent of annual U.S. electricity consumption.”
• “According to the Association of California Water Agencies, water agencies account for 7 percent of California’s energy consumption and 5 percent of the summer peak demand.”
• “Ninety percent of all electricity used on farms is devoted to pumping groundwater for irrigation.”
• “End use of water – especially energy intensive uses like washing clothes and taking showers – consumes more energy than any other part of the urban water conveyance and treatment cycle.”
• “When water is diverted for irrigation before it reaches a dam, an enormous amount of energy – the foregone energy production – is lost.”