What is dam in hydropower plant? All Questions › Category: Electrical Power Generation › What is dam in hydropower plant? 0 Vote Up Vote Down Chetan Shidling asked 4 years ago I need short information. 1 Answers 0 Vote Up Vote Down Chetan Shidling answered 4 years ago The dam will be built across the river or lakes to give the head of the water. Those are classified based on their purpose, material, shape, and structural design.