In a separate sewer system, how is stormwater managed?

In a separate sewer system, stormwater is managed by being carried in a system that is distinct from the one used for sewage. This method allows for the effective management of both stormwater and sewage without the problems associated with combining the two. When stormwater is diverted to its own system, it can be conveyed to appropriate drainage areas, such as retention ponds, wetlands, or directly to water bodies, allowing it to flow without contaminating wastewater.

Using separate systems prevents issues such as combined sewer overflows (CSOs), where excess water during storms causes untreated sewage and stormwater to mix and overflow into natural water bodies. In contrast, a separate system ensures that stormwater is handled properly, minimizing pollution and protecting water quality, significantly enhancing urban drainage management.