Hydroelectric dams are a form of water power. It works like this; the dam would prevent most of the water from crossing to the other side of the dam. Because very little water can leave one side of the dam, that side would have a higher water level. There is a tunnel in the dam, which permits some water to enter the inside. That water, because the water level is so high, would fall and have great momentum thanks to gravity. The fast moving water would then hit the turbine, which would spin from the force. That spinning motion would generate electricity, which we could use in our homes.

Wave power or tidal power is another form of water power that is used in the ocean rather than a river. The tide would push water into a cylinder and turns the turbine inside. Then, it would also generate electricity. This version of water power doesn’t always work as well as hydroelectric dam because the tides aren't always strong enough to push the water into the cylinder.