Surface erosion rills are dominant structures in young developing ecosystems, and as such they fundamentally affect water flows, for example by locally changing the infiltration capacity of the soil. To successfully model the hydrology of a slope system, it is therefore indispensable to simulate the generation of the erosion rills adequately. We applied three model approaches to the artificial catchment 'Chicken Creek' (Germany) to simulate the emergence of the erosion rills. First, we used the contributing area to detect surface water flow paths in the catchment. Second, we tested a surface runoff model based on Manning's equation. Finally, a self-organised channel network approach was used, where soil erosion was simulated based on the exceedance of local critical shear stress thresholds. We discuss the pros and cons of the three approaches and compare the predictions with observations (based on aerial photographs) to deduce the mechanisms determining the erosion rills.