Increased global trade in agricultural commodities has boosted fresh water consumption. This export of ‘virtual water’, embedded in products sold abroad, has increasingly affected local communities and ecosystems, especially in arid regions. Recent initiatives to certify agricultural production are showing a rapidly growing interest in considering water issues within schemes of quality assurance, sustainable production and fair trade. This article scrutinizes current water sustainability certification schemes, and how they affect local water user communities. The authors use three notions of governmentality to examine water sustainability standards and how they aim ‘to conduct the conduct’ of water users: (1) standards as ‘production of truth’ and ‘mentalities’ that constitute systems of collective rationalities, values, norms and knowledge; (2) standards as networks that prescribe roles and establish power relations between companies and producers; and (3) standards as ‘techniques of visibilization’ that control practices and discipline producers. Private standards in general reinforce the political and market power of private sector agro-food chains in local water management, to the detriment of local water user communities and national governments. However, sustainability certification could also potentially enable local, regional, national and international organizations of user communities to stake claims and negotiate to protect their water sources and livelihoods.