**4. Conclusion**

Due to the aging, poor construction quality, and maintenance, water damage and other adverse factors make it a prominent risk for the Chinese reservoir management institution. In the face of the long-term challenges of the disease-risk reservoirs, it is an effective way to solve the problems of the disease-risk reservoirs by disposing of the ones with serious disease risk, shrinking function, and technically unfeasible and economically unreasonable danger reservoirs while taking engineering measures to remove and reinforce them.

Based on economic rationality theory and flood consequence assessment, two decision-making methods of dam retirement are put forward. The flood consequence method is applied on the case of Heiwa reservoir; key evaluation indexes are compiled from the aspects of ecology, economy, and society; and the evaluation system based on single index is constructed. Comparing the plans of current dam situation, dam removal, and dam removal combined with urban flood control measure, the flood risk influence is evaluated. The evaluation results show that the reservoir scrapping will not have significant effects on the flooding situation in downstream cities. Besides, the urban flood control regulation measures could greatly mitigate the urban flood risk.
