water power 
noun [mass noun]
Power that is derived from the weight or motion of water, used as a force to drive machinery.There are other ways of conserving our energy, such as water power, and nuclear power stations, which the Government seem to be closing down....
- Steam engines were used first for pumping water from mines, and then in providing mechanical power for textile mills - hitherto driven by water power.
- The city's first electricity was produced by water power from the power station, which is now the Mill pub, and gas was piped from the Gas Works in the St Paul's area of the city.
Derivatives
water-powered
- One illustrates an upper-level millstone powered by a lower-level horizontal waterwheel; the other describes a water-powered reciprocator working a flour sifter to the right of the central flour mill.
- The production of textiles, which changed so dramatically later in the nineteenth century with the advent of fully integrated water-powered mills, also required intimate knowledge and direct use of nature.
- By 1840, a locally financed firm of British machinists adopted water-powered machines, to make woolen and merino shirts and drawers like those of their native Leicester.