This paper explores how the state-led ‘freshening the coastal zones’ policy has been implemented in pursuit of sustainable development in the Vietnamese Mekong Delta. Drawing on a case study of the Ba Lai irrigation scheme in a coastal district of Ben Tre Province, the paper argues that the state’s ideology of ‘freshwater over saltwater’ results in contested land-use policies that, in turn, drive forced transformation of resource-based livelihoods. By unraveling the political ecology of these social-political dynamics, the study shows how contemporary land-use approaches have modified coastalscapes, evidenced by the continued expansion of freshwater-based agricultural systems. These agriculture-favored development policies have negatively affected agrarian communities’ options to sustain their traditional livelihoods (e.g. shrimp farming), which otherwise help yield higher incomes. This paper raises doubts about the ‘freshening coastal zones’ policy in addressing saltwater intrusion at the delta scale, while recognizing the equal role of saltwater in supporting coastal livelihoods.