How much water per amps comes from a hydro electic plant in gallons per amp?

Answer 1

are you asking how many gallons of water are required to produce one amp of electricity?

Answer 2

There's no simple answer to this question. The water would drive a wheel or turbine. The mechanical power input from the water is the product of the rate of water flow (gallons/sec) and either the pressure, the head (amount of change in height the water goes through in passing through the wheel/turbine), or the square of the velocity. The wheel/turbine converts the water's own power to mechanical power in the form of a rotating shaft, which then drives an electrical generator. The electric power is the product of the mechanical power of the water, and the efficiencies of the wheel/turbine and the generator. The current (amps) produced depend on the electric power and the design voltage of the generator.