Cities depend on other regions because of their size, activity level, and lack of resources. Their water and energy are embedded in economic trade and transactions, so they are linked with other areas through socioeconomic networks. The equity implications of water-related energy interdependence have not been explored in South Korea, even though energy production and consumption are unevenly distributed across the country. This study analyzed Seoul's dependence on other regions for its water-related electricity consumption and the impact of Seoul's water-saving efforts on other regions' electricity generation. It used an interregional input-output analysis that included 16 regions and nine sectors. The study found that Seoul produced only 3.2% of the electricity that was required to supply water to the city: the balance came from other regions. Seoul conserved 64,671,551 m(3) of water from 2013 to 2017 by harvesting rainwater, reusing water, and reclaiming wastewater. This resulted in reduced electricity production, mostly in other regions, by 14,799.36 MWh. By incorporating regional equity, this study identified additional benefits from saving water in a city. This can lead to more constructive management of water and energy. (C) 2021 Elsevier Ltd. All rights reserved.