Final answer:
Reservoirs are man-made structures used to store water for drinking or irrigation. They are created by building dams in rivers and provide various benefits but also have drawbacks.
Step-by-step explanation:
Reservoirs are man made structures that are used to store water for drinking or irrigation. They are created by building dams in rivers, which collect water during wet times and store it for use during dry spells. Reservoirs have several benefits including providing water for urban supplies, hydroelectricity, flood control, and recreation. However, they also have drawbacks such as evaporative water loss, erosion, and environmental impact.