What is one benefit of having large dams and reservoirs? 

A)  They facilitate migration of fish. 
B)  They are inexpensive to build. 
C)  They reduce the danger of flooding occurring upstream. 
D)  They can be used to provide electric power.

Large Dams

Massive structures built across rivers or other bodies of water to control water flow, supply water for irrigation, and generate hydroelectric power.

Reservoirs

Artificial lakes or storage areas created by constructing dams across rivers or streams to store water for various purposes such as irrigation, power generation, and drinking water supply.

Electric Power

The flow of electrical energy through a conductor, used for a multitude of applications including lighting, heating, and powering machinery.