What does the term "water horsepower" refer to?

The term "water horsepower" specifically refers to the power put into water by a pump. It is a measure used to quantify the output power produced by the pump when it moves water. This calculation involves the flow rate of the water and the pressure at which it is being pumped. Essentially, it determines how efficiently the pump is converting electrical or mechanical energy into hydraulic energy to move water, which is a critical consideration in water treatment and distribution systems.

Other interpretations of power related to water, such as the power generated by natural water flow—like in hydropower generation—do not align with the definition of water horsepower, as this term is focused on the mechanical input from pumping. Similarly, while the power required to treat water and the power lost in distribution are important concepts in water management, they do not pertain directly to the specific metric of water horsepower.