Although essential to successful environmental governance, public participation has been sporadic and fragmented in China. Drawing on in-depth interviews conducted in the southern Chinese cities of Shenzhen and Guangzhou, this paper explores how environmental non-governmental organizations (ENGOs) have carried out ‘civilian river chiefs’ projects as novel approaches to water governance. We propose a framework of ‘double embeddedness’, within which ENGOs have built political and social legitimacy, reciprocity, and networks that enable their sustained participation in water governance. Our findings suggest that new patterns of state–community–non-governmental organization relationships are key to understanding public participation in China’s future environmental governance.