Climate change and water supply in the Mekong Delta and Ho Chi Minh City

The combination of natural and induced land subsidence, sea level rise and other effects of climate change, such as extended periods of drought, greatly affects agriculture and water supply. It aggravates and accelerates sea water intrusion further inland and reduces the availability of fresh water as a source for public water supply. The salinity of the groundwater that is used for public water supply in the city of Soc Trang in the Mekong Delta is locally very high. A surface water treatment plant will be constructed to dilute or substitute the groundwater with a chloride content exceeding the Vietnamese standard of 250 mg/l for clean water. Ho Chi Minh City relies largely on rivers for its public water supply. Raw water is taken from the Dong Nai and Sai Gon rivers. The salinity of the water of these rivers varies substantially with the tides and with the season. During the dry season with limited natural discharge salinity can exceed the Vietnamese standard for chloride. Construction of impounding reservoirs would allow selective intake of river water when salinity is relatively low.