Tropical river deltas are hotspots of humanactivity, but their vulnerability to flood risks is increasing due to sea levelrise and worldwide conversion of mangroves, acting as natural buffers againstmarine flooding, into human land use. Moreover, extreme sea levels notablydriven by climatic fluctuations such as the El Niño-Southern Oscillation, areprojected to intensify with global warming. Hydrodynamic models offer avaluable tool in reaching a better understanding on the distribution of extremesea levels in tropical deltas, but often their development is hampered by datascarcity. We combined state-of-the-art techniques to overcome that challenge bysetting up a TELEMAC-2D model for the Guayas delta (Ecuador), a large (± 3,000km2) delta with a complex geometry of branching river channels and mangrove forests.First, we used remote sensing to (1) obtain channel widths, which in turndetermine the cell size in a flexible mesh, allowing us to capture bothregional and local processes, (2) estimate intertidal flat topographies, and(3) delineate intertidal mangrove forests. Furthermore, we used analong-channel-coordinate interpolation to ensure channel connectivity inchannels with scarce bathymetric observations. Finally, to capture the land-seagradient in the water surface slope, we referenced all bathymetric and tidegauge data to a global geoid. Applying these techniques allows us to build amodel which simulates tidal ranges (of 2 to 4 m) with an error ranging between5 and 50 cm (i.e. 2.5 and 12.5 % of the observed tidal range), depending ontide gauge station. In a next stage, our model can be used to test how both ElNiño and land use changes affect extreme sea levels in this tropical delta.