Hydroelectric power plants can generate huge amounts of electricity. which of these statements best describes the impact of a hydroelectric power plant on the environment?
it pollutes the air.
it reduces the level of groundwater.
it causes floods in vast areas of land.
it contaminates surface water by dumping wastes.

Hydroelectricity provides about 7 percent of the electricity generated in the united states. (a) explain how a hydroelectric power plant converts energy stored in water into electricity. (b) identify two factors that determine the amount of electricity that can be generated by an individual hydroelectricity power plant. (c) describe the two main types of land-based hydroelectric power plants. (d) describe two economic advantages and two environmental disadvantages of hydroelectricity.