Freshwater is sold in certain areas for VND200,000 ($8.6) per cubic metre, and local authorities use tanker trucks to deliver water to households.
For more than a month Tran Minh Chinh of Can Giuoc District in Long An Province has had to buy from trucks for his family of five. He says the annual rainfall is a month late, causing all freshwater reservoirs in the area to dry up.
"The price of water is now VND60,000-200,000 ($2.6-8.6) for one cubic metre. A family of 4 to 5 members has to pay about VND1 million ($43) for water monthly."
People have to conserve water by every means possible. Water used for rice rinsing is saved for plants and livestock, bathing is done using salt water followed by a quick rinse with freshwater.
Nguyen Van Minh, a farmer, said: "Some areas are far away from provincial centres and inaccessible by trucks, so people there may not have water to use despite having money."
Due to the long drought, seawater has intruded 80km inland from the Vam Co Dong estuary.
The Long An Province’s military command has deployed three tanker trucks to deliver 20 cubic metres of water to affected wards.
People in other provinces across the delta too are struggling with drought.
Sitting by his harvested crop, Duong Van Chau, 70, a farmer in Chau Thanh District, Tra Vinh Province, is unable to hide his concern about the lack of water for the summer-autumn crop seeding.
"Freshwater in the irrigation system is stagnant and contaminated by chemicals from fertilisers, pesticides and residual pathogens. We have to wait for rainfall to seed the fields, which is at least a month away."
Water for daily requirements is drawn from wells.
According to local governments, saltwater intrusion is more severe this year than in previous years and salinity levels in major canals are high at 10-30 parts per thousand (ppt).
In Kien Giang Province, estuaries near Rach Gia city have salinity levels of 28-32 ppt.
Authorities have closed dams and sewers to prevent saltwater from entering agricultural areas.
According to Le Anh Tuan, deputy director of the Institute of Climate Change Research, Can Tho University, the recent drought is due to the El Nino phenomenon though it is not as intense as in 2016.
The effects of climate change are exacerbating the impacts, he said.
In 2016 an unprecedented drought, and saltwater intrusion, caused water shortages for 600,000 households and salinized 160,000 hectares of land, causing losses worth VND5.5 trillion ($237 million).