After the channel regulation from Shuanggang to Chuxi estuary of Raohe River，there are some shallow sections obstructing navigation in extremely low water conditions in 2022.Based on the measured data and mathematical model calculation，this paper calculates and analyzes shoal evolution，designed water level changes of the basic station，and the lowest navigable water level.The results show that the navigation channel from Zhupaoshan to Chuxi estuary is mainly cut down，with an average value of 0.7-3.0 m and a total scouring volume of 1.373×106 m3.Meanwhile，the hydrological series are extended to 2021，and the designed water level drop of the basic station will be 0.12-0.61 m.Under the designed lowest navigable flow，the maximum water level decline in lake reach of Raohe channel is 0.13-0.25 m，with an average of 0.05-0.11 m.