Laboratory flume experiments of shallow overland flow show that sediment transport occurs in a highly organized manner. The organization of the sediment on the bed reveals an evolution with several scales ranging from saltation of particles at a very low concentration to movement in waves at higher concentrations. The wave modes appear during a post saltation state that severely impact the transportation capacity. The wave modes consist of stripes and meanders. The temporal evolution of transport rates in the equilibrium stripe mode indicates smaller time scales (~ 10 sec) compared to (~ 10 min) the larger spatial scale structures such as meanders. Power spectra of the transport rate fluctuations characterize the stripe mode with multiple peaks at at different frequencies.