Final answer:
Hydraulically overloading a sewer can cause untreated sewage overflow and potentially lead to the corrosion of the sewer system, which is a condition not recommended and is harmful to the environment.
Step-by-step explanation:
Hydraulically overloading a sewer means putting more water into the system than it is designed to handle. This is typically not a practice intended for maintenance, nor does it improve sewer durability or prevent blockages. On the contrary, when sewers are hydraulically overloaded, such as during heavy rainfall events in combined sewer systems, they can lead to the overflow of untreated sewage into adjacent water bodies, contributing to water pollution and potentially causing corrosion to certain types of sewer infrastructure.
Combined sewer systems, while historically significant for managing urban wastewater and stormwater, are susceptible to overflow during heavy rain, which can compromise water quality. Advanced wastewater treatment and management strategies aim to minimize such overflow events by separating stormwater from wastewater, adequately treating sewage, and using overflow mitigation infrastructure like underground caverns and abandoned quarries.