PURPOSE: To enable water in a storage water tank to be forcibly fed to a water turbine chamber in a hydraulic power plant, by continuously performing the drawing up and delivery work of water rapidly by a bucket.

CONSTITUTION: A feed water bucket 8 is lifted on a storage water tank 7 by rapidly lifting an elevator rope R and the bucket 8, hitting an operating arm to a bottom roller, is tilted around a hinge pin serving as a support point toward the side of the storage water tank, permitting the delivery of water in the feed water bucket 8 into the storage water tank 7. Then the empty feed water bucket 8 is submerged in a reservoir water tank 3 by rapidly lowering the elevator rope R, in this way, water in the reservoir water tank 3 is drawn up into the feed water bucket 8. Accordingly, the water in the storage water tank 7 under a full water condition can be allowed to flow down and forcibly fed to a water turbine part 5 through a pressure head water pipe 6.