Emerging climate-development processes jeopardize water supply, especially in the Global South. In the Vietnamese Mekong Delta, disrupted water flows driven by climate change and hydropower development have caused water scarcity, threatening agricultural systems in both upstream and coastal areas. Based on insights from desk reviews, stakeholder workshops and interviews with local informants, this paper argues that while grey (engineered) solutions take precedence in addressing water scarcity, securing water sustainability (water retention) for agricultural resilience demands integrated ‘grey–green’ (engineered-nature-based) solutions. This paper suggests demands for translating this approach into the water governance framework for the delta’s agricultural development.