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Selecting the appropriate model structure for overland flow modelling is an important task in drainage design and floodplain simulation. Comparison of overland flow models based on dimensionality and by applying hydrodynamic principles for same roughness coefficient is a topic to be investigated. The work evaluates the ability of three types of one-dimensional model structures by applying non-linear reservoir routing (MS-I), kinematic wave routing (MS-II and MS-III) and a two-dimensional model structure by applying diffusive wave routing (MS-IV) for 16 events, each on an impervious experimental watershed. These model structures are used for a V catchment, and a comparison study is done using reference hydrographs. The analysis indicated that model structures that conceptualized the flow process as 2D produced better results after time offset bias corrections for hydrographs. If the resultant slope of the overland flow planes largely deviates from the dominant flow direction, then two-dimensional hydrodynamic models (MS-IV) are essential to simulate the overland flow process. Average NSE of 0.99 and 0.96, RSR of 0.11 and 0.15 are obtained for equilibrium and non-equilibrium storm events after bias corrections for MS-IV. However, if the deviation is marginal, then one-dimensional hydrodynamic models (MS-III) are capable of simulating flows with reasonable accuracy.