Currently, electric power generation is one of the largest water withdrawal and use sectors in the U.S. Additionally, future energy development such as biofuels production, hydrogen fuel or synthetic fuels production, oil shale development, carbon sequestration, or nuclear power development could significantly increase water use and consumption. On the other hand, water resource development — distribution, treatment, and transmission — is one of the largest energy use sectors. As future demands for energy and water continue to increase, competition for water between the energy, domestic, agricultural, and industrial sectors, could significantly impact the availability of water supplies for energy development, thus impacting reliability and security of future energy production and electric power generation. Therefore, it is critical that water and energy resources planning and development be integrated and coordinated across state and regional boundaries. This paper provides a short overview of the emerging energy-water challenges and issues identified in a recent series of national workshops on energy and water related issues as well as summarizing the research and development needs to address these emerging energy and water challenges.