In Mongolia, both energy facilities and mining operations are thirsty for water. Mining operations, which need water for production, are rapidly changing the water and energy landscape in the country. Until recently, the agriculture sector was the dominant user of water but mining is an increasingly large user. Energy production requires water for mining, fuel production, hydropower, and other needs. Conversely, water systems need energy for pumping, water treatment, transport and distribution, and other uses. In Mongolia, the water-energy nexus is of increasing concern. This publication examines the interdependency between water and energy systems in Mongolia.