Hydroelectricity Waterpower, power derived from the fall of water from a higher to a lower level, and extracted by means of waterwheels or hydraulic turbines (see Turbine). Waterpower is a natural resource, available wherever a sufficient volume of steady water flow exists. The development of waterpower today requires extensive construction, including storage lakes, dams, bypass canals, and the installation of large turbines and electric generating equipment. Because the development of hydroelectric power requires a large capital investment, it is often uneconomical for a region where coal or oil is cheap, even though the cost