Method of regulating a water level of a dam installation having a plurality of turbine generator units arranged to generate electrical power, wherein at least some of the plurality of turbine generator units are arranged at least one of one above another and one beside another so as to form at least one turbine generator module. The method includes regulating, at least to some extent, the water level to a predefinable set point by starting or stopping at least one of the plurality of turbine generator units and adjusting, in discrete steps, a quantity of water which can flow through the dam installation, wherein a discrete step is defined by a quantity of water which can flow through a defined number of turbine generator units.