Residents said the problem has persisted for months, with foul-smelling wastewater affecting nearby communities and visitors.
The drainage network was originally designed to carry stormwater but was later connected to the area's domestic sewage system. The additional wastewater overloaded the pipes, causing sewage to back up and overflow through manholes.
Authorities said four overflow points remain after repairs were completed at two others.
As a temporary measure, the local government has cleaned all 27 manholes along the affected stretch. It also plans to repair the remaining leaks, widen drainage pipes and modify sections of the network to prevent future overflows.