What type of maintenance is crucial for managing water pressure in distribution systems?

Periodic flushing of pipelines is essential for managing water pressure in distribution systems because it helps to remove sediment, buildup, and debris that can accumulate in the lines over time. This accumulation can restrict the flow of water, leading to fluctuations in water pressure, potential clogging, and reduced efficiency of the distribution system. By regularly flushing the pipelines, utilities can maintain a consistent and adequate water flow, ensuring that pressure levels remain stable throughout the system.

Routine calibration of pumps is important for optimizing performance but does not directly address issues related to sediment build-up in the pipelines. Seasonal adjustments of water levels and annual inspections of reservoirs are also necessary for overall system health but are not specifically focused on the immediate management of water pressure in the distribution lines. Flushing directly tackles the problem of pressure by keeping the pipelines clear, making it the most effective method among the choices provided.