Sediment transport in overland flow interacts dynamically with the soil surface morphology, which is often assumed to be static. This assumption, although it limits the predictive capacity of models, is reasonable since the morphological evolution is difficult to quantify, particularly when rill networks form. Rill networks evolve due to hydraulic interactions with local features of the surface, the measurement of which are challenging even in well controlled laboratory experiments. In nature, river basins with different sizes and at different places are found to have power law relations for the exceedance probabilities of area and upstream length. We hypothesize that similar scaling relations exist for rill networks. Here we present the initial results of laboratory experiments to test this hypothesis.