Extreme droughts are affecting millions of livestock farmers in Sub-Saharan Africa, causing water shortages, famines, migration, and fatalities. The construction of new small water infrastructures (e.g., wells, boreholes, and small dams) is increasingly supported by NGOs and national governments to improve water availability for agro-pastoralists, especially as an emergency response to extreme droughts. While the short-term benefits of small water infrastructure are clear, their potential cumulative impact and their long-term effects on the resilience of drylands communities remain unclear. Building on in-depth anthropological literature from five key African drylands, we model post-drought pastoralists' dynamics related to small water infrastructure. We show that while developing new water points releases water shortages in the short term, it can erode the traditional adaptation practices without adequate governance. This can cause unexpected long-term impacts, such as sedentism, overgrazing, rangeland degradation, and groundwater depletion. We further illustrate how our model captures early quantitative signals of resilience loss in dryland Angola, where large-scale implementation of small water infrastructure is being delivered in response to the worst droughts ever recorded in the pursuit of increasing climate resilience.