For a bed material of median size 22 mm and a range of water discharges 0.01 − 0.10 m3/s and at slopes of 3%, 5%, 7% and 9%, bedforms in a laboratory flume (0.6 m wide) are found to consist of antidunes and alternate bars while flow resistance is shown to depend on sediment movement and type of bedform. Following initiation of sediment movement (generally at Froude numbers >1 and consisting entirely of bedload) the bedforms develop immediately and prevent the retention of a plane bed. Antidunes appear at almost all flows but, at the lower discharges at the two higher slopes, they are replaced as the dominant but not exclusive form by alternate bars (Fig. 1). Because of the limited flume width, though, it is not possible to define the entire region in which bar development is possible. Wavelength of the bars varies inversely with channel slope (Fig.4). For the plane beds with little or no sediment transport the flow resistance varies smoothly and inversely with the ratio of depth to sediment size (Fig. 5). Once sediment transport and bedforms are generally established, the flow resistance is increased by the distortion of flow about the bedforms. At higher discharges the flow resistance varies according to the type of bedform and the measured sediment discharge (Figs. 5 and 6).