This course introduces students to the planning, modeling, and management of water systems in real-world contexts where decisions must balance water supply, floods, droughts, infrastructure, ecosystems, and future uncertainty. Students will learn core concepts in water resources management through water allocation methods, optimization theories, system simulation models, and the basics of hydrologic and reservoir models. Students will gain data analysis skills to support practical decision-making in competing constraints and objectives, such as reservoir operations, water supply planning, and long-term infrastructure design under weather extremes and a changing climate. The course combines conceptual lectures with hands-on modeling exercises in operational hydrologic models, as well as playing games as a real-world dam operator to control a dam. Step by step instruction in scientific computing using MATLAB will be taught for students, and no prior programming experience is required. Large-scale Language Models (LLMs) will also be demonstrated to help with simple coding for students without formal training in computer science programming. This course is also designed to support research-oriented training for MS theses, capstone projects, and PhD research by guiding students through problem formulation, literature review, experimental design, and technical communication and presentation. The course emphasizes the integration of theory, applications, system thinking, and research practice for students in Sustainable Systems, Geospatial Data Science, Ecosystem Science and Management, and other specializations to further develop system skills and knowledge.