In Namibia, rural water governance has changed profoundly during the last two decades. Today, in many rural communities, user associations administer water and set the rules for management practices. Their rules typically define boundaries and specify contributions that vary for members and outsiders. When the rains failed in 2012–14, the mobility of people and herds increased and put the newly formed institutional regimes to a critical test. Based on long-term ethnographic fieldwork in seven communities, we examine whether and how management regimes were either altered or applied. The results indicate that cultural models of kinship and reciprocity took priority over formal agreements during the drought. Non-adherence to formalized practices and to rules of excluding outsiders also expresses a certain resistance to the interpretation of water as an economic good.