Abstract: After seven decades of construction, the Yangtze River basin’s control reservoir group has reached completion. The joint operation of cascade reservoirs, with the Three Gorges reservoir as its core, has been ongoing for ten years. This study presents an analysis of the achievements, challenges, and solutions stemming from this joint operation in flood control, water supply, ecology, and emergency response. The findings underscore the pivotal role played by joint reservoir group operation in flood control, drought relief, water supply, ecological preservation, and emergency management. The main challenges identified are climate change and the uncertainties in medium- to long-term hydrological forecasts. Additionally, management issues such as coordinating interests between joint reservoir group operations and single reservoir multi-objective operations, quantifying operational effectiveness, and devising fair compensation mechanisms are also significant hurdles. The primary solution proposed involves strengthening the “Four Preemptive” system, namely, forecasting, early warning, contingency planning, and rehearsal, to address climate change uncertainties and human activities’ impacts. Furthermore, enhancing joint reservoir and water network operations can significantly bolster water security of hydraulic projects. Establishing a scientifically sound and equitable joint operation system and mechanism for water project groups emerges as a crucial and effective measure.

Key words: cascade reservoir group, water network project, joint operation, changing environment, countermeasures