For what primary purpose are hydrants used in water distribution systems?

Hydrants serve a crucial role in water distribution systems primarily for firefighting purposes. They are strategically placed throughout a community to provide quick and easily accessible points where firefighters can tap into the municipal water supply during an emergency. The high flow rate and large water volumes available from fire hydrants are essential for effectively combating fires, as they enable firefighters to deliver the necessary water to extinguish flames rapidly.

While hydrants can also be used for flushing the system or testing water quality, these activities are secondary to their primary function. Flushing helps maintain water quality by removing sediment and stagnant water, and testing water quality is done to ensure that the water meets health standards. However, neither of these purposes matches the critical need for immediate access to large quantities of water in fire emergencies. Storing excess water is not a function of a hydrant; instead, they rely on the pressurized distribution system to provide water on demand. Thus, the primary function of hydrants in a water distribution system is indeed to provide access to water for firefighting.