Due to growing human activity in coastal zones, there is an increasing stress on salt marshes all over the world. These intertidal wetlands were often seen as coastal ‘wasteland’ and large areas were reclaimed for urban development and agriculture. In Puget Sound, a system of interconnected marine waterways and basins in the northwest of the United States, this has lead to an 80% loss of marsh area in the last 150 years. In recent years however there has been a growing recognition of their value as habitat for fish, birds and numerous species of plants and as coastal protection. In many countries they are now protected areas and numerous restoration projects are being carried out or planned. One of the largest of these restoration projects takes place in the Nisqually River estuary, in the southern end of Puget Sound. By removing a dike, built in the early 1900s for farming purposes, an area of nearly 405 hectares was reintroduced to the salt water and tides of Puget Sound on November 12, 2009. The goal of this study was to research how this dike removal will affect the estuary in the coming years. A computational model was set up in Delft3D to describe hydrological and morphological processes, with focus on the interaction with vegetation. The vegetation in Delft3D is schematized as cylindrical rods, which add extra source terms to the momentum equation. An external Matlab routine was used to calculate changes in the vegetation field based on the model results. Because this type of vegetation modeling had not been done on this scale before and there were large uncertainties in the required parameters, first a sensitivity analysis was carried out with a schematized model. By doing different runs, changing one parameter at a time, the relative importance of each parameter was examined. The most important parameters were then researched further so that a detailed final model could be set up, with a discharge from the Nisqually River on the southern boundary and tidal forcing on the northern boundary. With the use of a morphological factor a period of 10 years was simulated. Due to limitations in computation time and the lack of some important data, concessions had to be made in the setup of the model. These concessions, combined with the fact that the model could not be validated since there were no post-restoration measurements available at the moment of writing, make it hard to determine the accuracy of the model predictions. Therefore the results should not be seen as an exact prediction, but more as a qualitative impression of how the area is going to develop in the coming years. It was concluded that success of salt marsh restoration mainly depends on elevation. Higher areas are inundated for a shorter amount of time, which makes it easier for pioneer vegetation to establish. During the period in which the restoration area was diked no sediment was brought in, which caused subsidence. As a result, a salt marsh can develop in the eastern part of the estuary but the western part of the estuary is too low to be colonized. However, the dike removal will allow sediment from the Nisqually River to enter the area again, so if enough sediment is provided the elevation will increase, allowing the marsh to expand further. This suggests that sediment discharge from the river is a key factor, and it is therefore recommended to measure this in the future. An alternative scenario, in which the river is forced to flow through the restoration area, was also examined, based on expectations for high river discharges. This increases the amount of sediment that is imported into the area, and could therefore have a positive effect on the salt marsh development. It does however also influence the salinity, which has a large impact on the distribution of vegetation. Further research into these effects is recommended if forcing this change is considered.