3D hydrodynamic simulations were performed on an area extending 600 km off Taiwan island for the period running from September 2011 to December 2012. We covered a winter Monsoon season and a summer season with 17 typhoons recorded. By comparing simulations and measurements during the TALIM typhoon, our model reproduces correctly the storm surge observed along the Wan-Tzu-Liao sand barrier (South-West Taiwan). By a modelling approach, we analyzed the regional hydrodynamic mechanisms which control the sea surface elevation at the Chung-Chin harbour. Tide is the dominant forcing of the water level with more than 1 meter above the mean sea level. Global currents contribute up to 80 cm to the water level but during the SAOLA typhon, the elevation reached 1 meter. The contribution of atmospheric forcings is lower but it can generate 30 cm of elevation (e.g. during GUCHOL and TALIM typhoons).