Abstract: A water diversion project(WDP) is one of the main engineering measures to relieve the uneven distribution of water resources and the conflict between water supply and demand.The WDP is also important for ecological environment restoration.However, the intervention of WDP inevitably have complex physical, chemical, hydrological, and aquatic biological effects on the water-carrying lakes along the diversion route.Furthermore, the migration and transformation mechanisms of contaminants in these lakes are also changed.We analyzed the effects of WDP on water hydrodynamics, physicochemical properties(i.e.,suspended particulate matter(SPM),water transparency(WT),and dissolved oxygen(DO)) and contaminants(i.e.,nutrients, heavy metals, and organic pollutants) in water-carrying lakes.The result indicated that the WDP generally enhanced the hydrodynamic conditions in water-carrying lakes.The velocity gradient and water shear stress increased as the flow increased and the water depth was shallower.Meanwhile, the increased velocity and water shear stress affected the morphological characteristics of SPM,and increased SPM concentration, DO, and WT in small-scale lakes.Although the WDP reduced the average water age in the lake and promoted water circulation, it also stimulated the endogenous release of contaminants, including nutrients, heavy metals, and organic pollutants.Therefore, water diversion schemes could be used as emergency measures to improve water quality, and they could not become the fundamental measures to solve the problem of lake eutrophication.This research can provide a comprehensive assessment of the effects of WDP on ecological environment in water-carrying lakes, and provide the scientific basis for establishing a more reasonable water diversion scheme.