What phenomenon occurs due to closing hydrants and valves too quickly?

The correct answer is water hammer, which is a phenomenon that occurs when there is a sudden change in the flow of water within a piping system. This rapid change can happen when hydrants and valves are closed too quickly, leading to a shock wave that travels through the water in the pipes. When the flow is abruptly halted, the kinetic energy of the moving water has to dissipate, resulting in high-pressure surges. These surges can create loud banging noises and may potentially damage pipes, joints, and fixtures if the water hammer is severe enough.

Understanding water hammer is crucial for maintaining the integrity of water distribution systems. Proper operating procedures, including gradually closing valves and hydrants, help mitigate this phenomenon, ensuring a stable and safe water distribution network.