What does "hydraulic capacity" refer to in a collection system?

Hydraulic capacity in a collection system specifically refers to the ability to transport wastewater efficiently without causing surcharging. Surcharging occurs when the flow of wastewater exceeds the capacity of the pipes, leading to potential overflows or backups. Therefore, the hydraulic capacity is a critical aspect of sewer design, ensuring that the pipes can handle expected peak flows without exceeding their limits. It encompasses factors such as the diameter of the pipes, the slope of the sewer lines, and the materials used, which all contribute to the effective movement of wastewater through the system. This concept is vital for maintaining the integrity of the collection system and preventing environmental contamination.