A method and an apparatus for controlling an electric pump for furnishing water for injection into a combustion chamber of an engine are provided. The electric pump is connected to an inflow of a main water tank and has a high-pressure output at which the electric pump makes available water at a pressure elevated with respect to a pressure in the main water tank. The high-pressure output of the electric pump is connected to a return line that opens into a driving jet connector of a suction jet pump, a suction jet connector of the suction jet pump being connected to a further water tank, and a high-pressure output of the suction jet pump being connected to the main water tank.