Fresh surface water, groundwater, and their association play a pivotal role in sustaining ecosystems and human societies, especially with escalating demands due to population growth and climate change. Geographic Information Systems (GIS) have revolutionized water resource management by integrating spatial data, modeling tools, and decision-making processes. This chapter critically reviews various GIS-based modeling techniques utilized in water resource monitoring and management, highlighting their methodologies, data sources, key findings, and practical applications. Research gaps and challenges in existing studies are identified, emphasizing the lack of standardized methodologies, limited integration between hydrological models and GIS technologies, and difficulties in scaling GIS-based strategies to broader regional or national levels. To assist researchers and stakeholders, a novel data collection sheet is proposed to facilitate accurate data collection and replication of processes. The article offers an exhaustive analysis of surface water delineation methods, groundwater determination techniques, and the significance of Digital Elevation Models (DEMs) in watershed management. Through comprehensive tables, it provides insights into various techniques, algorithms, and satellite sensors used in GIS-based water resource studies. The chapter concludes by emphasizing the imperative need for collaboration, standardization, and innovation in GIS-based strategies to ensure efficient, effective, and sustainable water resource management for future generations.