The city's Department of Construction has sought feedback from relevant agencies on a proposed flood-control and wastewater treatment plan covering between 2026 and2060, along with a separate implementation plan for the 2026-2036 period.
According to authorities, the merger of Binh Duong and Ba Ria-Vung Tau into HCM City had significantly expanded the city's footprint, requiring a regional approach to flood control and wastewater treatment rather than one confined to administrative boundaries.
Flooding risks are rising amid the combined effects of climate change, sea-level rise, high tides and land subsidence.
Extreme rainfall has become more frequent in recent years, while water levels at the Phu An and Nha Be stations have repeatedly exceeded 1.8 metres, surpassing the capacity of many flood-control systems
The city also faces growing pressure to improve wastewater treatment, with only 17 per cent of its 1.97 million cubic metres of daily domestic wastewater treated to required standards.
Most of the remaining wastewater is discharged directly into the Saigon-Dong Nai river system and coastal areas, placing increasing pressure on the environment.
Officials said one of the main obstacles to effective flood control was an outdated planning framework.
Flood drainage plans approved in 2001 and flood-control schemes adopted in 2008 have expired and do not take into account current climate change scenarios or the pace of urban development, according to the department.
The city's previous flood-control and wastewater treatment programme, covering 2020-2045, was designed for the pre-merger HCM City, which covered just over 2,000 square kilometres.
Under the new strategy, flood control, wastewater treatment, water resource management, environmental protection and climate adaptation will be integrated into a single planning framework linked to land use, transport development and socio-economic growth.
Alongside infrastructure projects such as tidal gates, embankments, pumping stations and wastewater treatment plants, the city plans to expand measures including land-use management, smart monitoring systems and early-warning networks.
According to the HCM City Department of Construction, the city currently has 159 locations prone to recurrent flooding, including 76 in the former HCM City area, 52 in Binh Duong and 31 in Ba Ria-Vung Tau.