Abstract:The regulation works of the Jialing River waterway from Caojie to the estuary were implemented in stages.The regulation effect of some reaches was not as expected,and the navigation conditions were still poor.In view of the key navigation-obstructing shoal of Banjiubei and Erlangtang in the Jialing River waterway from Caojie to Beibei,a depth averaged two-dimensional model as well as field observation are adopted to analyze the navigation condition of the Jialing River waterway from Caojie to Beibei.Waterway and shoals characteristics,waterway regulation and the regulation effects on the river reach are summarized.In addition,the flow regulation requirement of Caojie Hydropower project for navigation purpose and the corresponding guarantee rate are put forward.The results show that though the waterway from Caojie to Beibei in the Jialing River has been systematically regulated in recent years,navigation flow condition has been improved,but influenced by terrain changes year by year,erosion and deposition in the channel changes significantly,already cannot meet the requirement of the channel dimensions Ⅲ level at present.Under the current topographic condition,the minimum discharge requirement of Caojie Hydropower station for grade Ⅲ channel dimensions is 1 391 m3/s.