There are three methods in general use for driving pumps in water-works, namely by steam-, Diesel- or electrically-operated machinery. It is the purpose of the present paper to compare the costs of such plant for each of six typical waterworks loads. An outline of the duties to be discussed is first given, with notes on the various kinds of machinery suitable. The method of arriving at the capital charges, with diagrams showing the cost of pumping units is next shown, and thereafter, the means of calculating the running expenses. The estimated annual charges are then set out in tabular form, followed by some notes on the results obtained. Appendices are included which provide an estimate of the costs of a heat pump for a pumping station; a demonstration of the losses caused by the rotor-resistance method of speed variation in pumping sets, indicating that such means of control can be economic; and finally an explanation for the need of standby generating plant in pumping stations.