A fuel cell system having flow fields capable to operate like interdigitated flow fields, but in the same time allowing the removal of liquid water collected in the high-pressure channels, throughout individual exhaust passages. In a preferred embodiment, the channels follow radial-circumferential trajectories, each channel being provided with individual exhaust passages. In another preferred embodiment, each channel is provided with a valve control in both individual supply passages and individual exhaust passages allowing the system to operate alternatively as an interdigitated flow field as well as an open-channel flow field.