A passive restriction passageway (for example, a passive capillary valve or a restricting orifice) positioned to drain accumulated liquid from a fuel cell reactant flow channel is used in conjunction with a control element for periodically adjusting the pressure across the passageway. The control element intermittently adjusts pressure across the passageway to enable liquid flow through the passageway. The restriction passageways and the adjustment of pressure periodically move liquid water through the passageways to drain liquid buildup from the reactant supply channels. Together, these features enable sustained performance from the fuel cell during operation and also prevent damage to the fuel cell when the fuel cell is exposed to freezing temperatures (especially after shutdown of the fuel cell).