Conventional water resource carrying capacity (WRCC) assessment methods often struggle to capture dynamic water-economy-ecosystem interactions and lack standardized, reproducible frameworks. This study introduces water accounting-particularly the System of Environmental-Economic Accounting for Water (SEEA-W)-as a comprehensive methodological upgrade for WRCC assessment. Through a systematic review of existing methods and a detailed case study, we demonstrate how SEEA-W integrates hydrological processes with socioeconomic data using a structured supply-use framework, enabling multi-scale, policy-relevant, and comparable assessments. Our analysis identifies five critical dimensions for enhancing WRCC practices: spatiotemporal scalability, standardized account compilation, data gap mitigation, integration with ecosystem accounting (SEEA-EA), and modular indicator development. The results highlight the potential of SEEA-W in identifying water-use conflicts, evaluating efficiency, and supporting sustainable water governance. Finally, we outline key challenges-such as data consistency and regional adaptability-and propose strategies for future advancement, including the adoption of hybrid data integration techniques and unconventional water resource accounting. This research provides a new pathway toward more systematic and adaptive water resources management.