Nexus of Energy and Water for Sustainability Act of 2019 or the NEWS Act of 2019 This bill establishes requirements concerning the energy-water nexus, which means the links between (1) the water needed to produce fuels, electricity, and other forms of energy; and (2) the energy needed to transport, reclaim, and treat water and wastewater. Specifically, the bill requires the Department of the Energy (DOE) and the Department of the Interior to establish a joint Nexus of Energy and Water for Sustainability (NEWS) Office and Interagency Coordination Committee on NEWS to plan for and coordinate energy-water nexus research, development, and demonstration activities. In addition, DOE must establish and carry out a smart energy and water efficiency management pilot program. Under the program, DOE must award grants to water authorities (i.e., authorities that provide water, wastewater, or water reuse services) for demonstrating unique, advanced, or innovative technology-based solutions that will improve the net energy balance of water, wastewater, and water reuse systems; support the implementation of innovative and unique processes and the installation of established, advanced automated systems that provide real-time data on energy and water; and improve energy-water conservation and quality and predictive maintenance through technologies that utilize internet-connected technologies.