Hydroelectric power is produced using the energy of moving water. which description tells how this process is accomplished? water flowing downstream moves through a reservoir in a dam and past turbines. it then moves through channels and cause a generator to produce electricity. water flowing upstream moves through a channel in a dam. the water moves though a generator that produces electricity, and then it moves to a reservoir. water flowing upstream is in a reservoir behind a dam. the water moves up through channels in the dam where it flows past turbines, moving them and creating electricity. water flowing downstream is held up in a reservoir behind a dam. some water moves down channels through turbines connected to generators which produce electricity.