What can result from transient pressure changes, or water hammer, in water distribution systems?

Transient pressure changes, often referred to as water hammer, occur when there is a sudden change in the flow of water, such as when a valve is closed rapidly or when a pump starts or stops suddenly. This phenomenon creates pressure surges that travel through the pipeline, which can result in significant damage.

The correct option points to the potential harm these pressure changes can cause. Water hammer can lead to excessive pressure on pipes and fittings, resulting in stress that might cause fractures, leaks, or even complete failures of the system. This kind of damage not only necessitates costly repairs and maintenance but can also lead to unscheduled water service interruptions, further compounding operational issues and costs.

In contrast, other options suggest outcomes that do not align with the realities of transient pressures. There is no improvement in pipe efficiency, no reduced flow rate in a positive sense (in fact, it can lead to erratic flow), and operational costs typically increase due to the complications introduced by water hammer. Understanding these consequences is essential for maintaining the integrity of water distribution systems and ensuring their long-term functionality.