Abstract: Method and apparatus for temporarily increasing the transport capacity of the water supply system in case of a calamity, in which despite the occurrence of a calamity an amount of drinking water is to be transported to the service area of a pumping station or transport line which has failed. In case of a calamity, at least one mobile apparatus for raising the pressure in the transport line is temporarily connected to the residual supply system to take over the failing transport function. The apparatus has a transportable housing with a pump coupled to a motor, comprising means for setting the pump on two sides into communication with a water transport line via connecting lines, and has a capacity sufficient for deployment in a municipal, regional or still larger water supply system.