Save water to save carbon and money: developing abatement costs for expanded greenhouse gas reduction portfolios.

The water-energy nexus is of growing interest for researchers and policy makers because the two critical resources are interdependent. Their provision and consumption contribute to climate change through the release of greenhouse gases (GHGs). This research considers the potential for conserving both energy and water resources by measuring the life-cycle economic efficiency of greenhouse gas reductions through the water loss control technologies of pressure management and leak management. These costs are compared to other GHG abatement technologies: lighting, building insulation, electricity generation, and passenger transportation. Each cost is calculated using a bottom-up approach where regional and temporal variations for three different California water utilities are applied to all alternatives. The costs and abatement potential for each technology are displayed on an environmental abatement cost curve. The results reveal that water loss control can reduce GHGs at lower cost than other technologies and well below California's expected carbon trading price floor. One utility with an energy-intensive water supply could abate 135,000 Mg of GHGs between 2014 and 2035 and save--rather than spend--more than $130/Mg using the water loss control strategies evaluated. Water loss control technologies therefore should be considered in GHG abatement portfolios for utilities and policy makers.