Problems of hydroelectric energy and how to solve it?

Hydroelectric powerhouses discharge water from a dam onto agricultural land. There may be times when the powerhouse needs to generate electricity, but the land below does not need the water. There may also be times when the agricultural land below the dam needs water, but electricity from the powerhouse is not needed. Compromises may have to be made between the owners of water rights, waterways management, and electric energy producers. Business as well as environmental decisions may be made so either water flows without electric generation or electricity is generated and the water flows to the ocean -- unused. This situation may occur because the time of day when water is needed (night) may not coincide with the time of day when electricity is needed most (early afternoon).