In the context of the climate crisis, water as a natural resource is under threat globally, and the Global South is of critical interest for political ecological studies. This article argues that environmental crises such as the "Day Zero" drought in 2018 in Cape Town (South Africa) can create possibilities for reformulating the deeply unequal hydropolitics stemming from colonial and apartheid regimes. The drought has enabled the politicisation of underground water, examined through an ethnographic study of a small-scale farming organisation in the Philippi Horticultural Area (PHA) of Cape Town. While tracking ways to secure the protection of natural resources such as aquifers in urban areas, the article further considers how such forms of activism around underground water have sought to "make the invisible, visible," thereby developing more inclusive forms of sensemaking. By providing an analysis of activism taking place during and after a period of acute water scarcity, it contributes to scholarship on emergent political ecological mobilisation in the climate crisis in the Global South.