In the recent past, the quality of surface water for  domestic use in the Vietnamese Mekong delta (VMD)  has been seriously affected by severe water pollution  and intense saltwater intrusion. This study aims to  assess existing surface water sources in the provinces  of Can Tho, Hau Giang, and Soc Trang. By assessing  the existing salinity status to point out areas of low  salinity frequency hazards, this work identifies suitable  areas through water quality assessments. The results  indicated that the Hau river and its tributaries from Ke  Sach (in Soc Trang) toward inland has a lower risk of  salinity. This indicated that water sources in Ke Sach  could be a possible raw water source for water supply  treatment plants in Soc Trang. Specifically, water  sources including the Hau river’s mainstream, Cai Khe  canal, Khai Luong canal, and Thom Rom canal in Can  Tho city, the Hau river’s mainstream, the Mai Dam  river in the Hau Giang province, and the Cai Con river,  the Hau river’s mainstream in Ke Sach, and the Cai  Vop and Cai Tram canals in the Soc Trang province,  could be exploited for water supply. However, a  treatment for pollutants such as BOD5, COD, TSS, and  total coliform in these water sources musts be taken  into consideration.