As a national strategic development zone， the water environment quality of the Lin-gang Special Area is crucial to achieving regional sustainable development goals. However， the rapid urbanization may further increase environment risks of the regional water. Based on the systematic analysis of pollution characteristics of routine pollutants and heavy metals in surface water and sediments， spatiotemporal distribution patterns and source diagnosis of pollutants were explored， thereby proposing water resources scheduling strategies to improve the water quality of the Dishui lake micro-catchment. The results indicated that： compared to the flood season， surface water in the non-flood season was more polluted， with water bodies in the water diversion area and east drainage area exhibiting characteristics of composite pollution by COD_Mn， Cd and Hg. During the flood season， total phosphorus （TP） pollution in the water diversion area is more prominent. Notably， TN exceeded the standard limit across all water bodies in both flood and non-flood seasons， particularly in the west drainage area. Sediments also show heavier pollution in the non-flood season than in the flood season， with Cd and Hg in all sediments exceeding the background value. During the flood season， TN enrichment occurs in the sediments of the west and south drainage areas. Source apportionment revealed that domestic sources （34.1%） and agricultural sources （22.7%） contributed significantly to pollutants in surface water， while traffic sources （38.9%） dominated the pollutants in sediments. Based on these results， the following strategies for improving the water quality are proposed： （i） Implement off-peak water diversion during the flood season while avoiding the peak period of agricultural non-point source pollution； （ii） Implement the strategy of prioritizing west drainage， followed by south drainage， and finally east drainage for the clear water diverted from the Dazhi River； （iii） Implement ecological ditch and ecological buffer zone strategies in the farmland of the upstream water diversion area to reduce surface runoff pollution load； （iv） Implement targeted control measures for individual points with abnormal concentrations， aiming to achieve the coordinated reduction of nitrogen， phosphorus， and heavy metals.This study provides a scientific basis for the transformation of water environment management in Lingang New City from "end-of-pipe control" to "water resources regulation" during the process of rapid urbanization.