Let / be the the height above the pump of the water reservoir and h the height where the water is to end up. Also assume M is the total mass of the water leaving the reservoir and m is the mass that reaches the final height, moving with a speed v. Use conservation of energy to derive a relationship for the mass of water, m that can reach the final height in terms of M, H, and h. Assume no energy loss due to friction. What percentage of M must be expended so that some water, m just reaches the higher reservoir (v=0)