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Irrigation projects often result in many far-reaching environmental changes.This paper takes example for the Hetao Irrigation District, the largest one along Yellow River in China and studies the impacts of agricultural water management on hydrology and environment.Long-term (1954-2013) data with regard to irrigation, drainage, soil salinity, groundwater and the environment of Wuliangsuhai Wetland, the drainage water receiving lake, were collected and analyzed.It shows that the uncontrolled irrigation and the absence of effective drainage have resulted in the rising groundwater table, the worsening soil salinization and also the expanding lake, which has become an important international wetland.The completion of artificial drainage system and the application of water-saving practices have good effects on lowering groundwater table and soil salinity control.However, soil salinity risk is still threating the irrigation system since salt is continuously accumulating inside and the TDS (total dissolved salts) of groundwater is getting higher.To control soil salinity, more effective drainage is necessary to drain more salt and lower water table, but this may do harm to natural vegetation and the eco-environment of Wuliangsuhai because the non-point pollution caused by agricultural drainage have pushed Wuliangsuhai Lake to a serious ecocrisis.The results also show that it is important to ensure a certain amount of drainage water with low TDS for securing the environment of Wuliangsuhai Lake.Therefore equilibrium needs to be achieved among soil salinity control, groundwater protection, natural vegetation recovery and wetland protection.And further research is strictly needed to provide optimal agricultural water management strategies, especially in the context of the ongoing water-saving renovation program.