Yes, it is! Hydroelectric energy is manufactured by having a source of moving water, such as a stream, or river, power the electric generator that makes the electricity. Water is a renewable resource; thanks to the water cycle, we always have a continual recycling of the water available here on Earth.
Compared to traditional electric power plants, hydroelectric plants do not require the burning of fossil fuels, which are nonrenewable resources. The nonburning of fossil fuels helps reduce the effects of global warming by reducing the amount of carbon dioxide gas that is produced. Those are good things!
The drawback to using hydroelectric plants is not enough locations. We simply do not have enough rivers available to power enough hydroelectric plants to supply the needs of our nation. Another negative is hydroelectric power is dependent upon the weather; if you reduce the flow of water in a river due to drought, there goes the power source for turning your generator.