Microtopography can play a very relevant role in rainfall partitioning into runoff and infiltration. Usually, however, do to data and computational constrains, microtopography is not explicitly accounted for. In this study, we perform simulations with a physically-based surface water solver together with time-dependant and constant infiltration rates, over a large number of surfaces with microtopography. Our results show that microtopography can have significant effects of runoff and infiltration, depending on slope and microtopographic features. Time-dependant infiltration may also magnify such effects.