An integrated two-dimensional depth-average numerical model was developed to simulate hydrodynamics and to track the fate and transport of contaminants in the Erh-Chung Flood Way wetland in northem Taiwan.The model was calibrated and verified with field data collected from Nov.8,2002 to April 13,2003.The RMA2 and TOXIWASP models were configured for the wetland system to model mass transport,suspended sediment as well as heavy metals.Hydrodynamic results from the RMA2 model were used to develop mass transport for the TOXIWASP model in the wetland system.Model results mimic the field data for suspended sediment and heavy metals.Results of model sensitivity analyses show that the partition coefficient is a key parameter for the fate and transport of heavy metals in the wetland system.