The water level of the Yaohe Hub is influenced by multiple factors,including the regulation of the Yaohe Sluice and the Gaotang Lake drainage pumping station,as well as the water diversion of the Yangtze-to-Huaihe water diversion project.The hydrological conditions upstream and downstream are complex,while the current hydrological data series of the hub have a short duration and exhibit inconsistency with the statistical samples of upstream and downstream stations,making it more difficult to determine the design navigation water level.To address these issues,comprehensive water level analysis and research are conducted.Based on water level data from various stations,the project water levels are determined using the water level frequency method and the comprehensive duration guaranteed rate method.By analyzing the water level variations between different stations within the same series and between different series of the same station,the trends in water level changes are identified.Combined with factors such as the hub's operation and scheduling,water resources allocation,and adjacent hydraulic projects,a more reasonable design navigation water level is derived through comprehensive analysis.The design highest and lowest navigation water levels for the upstream of the Yaohe Hub are 21.50 m and 17.02 m,respectively,while those for the downstream are 23.36 m and 16.34 m.