Groundwater is the largest freshwater resource, supporting drinking water, irrigation and ecosystems. As natural hazards intensify and intertwine with social, political and economic challenges, short-term groundwater use is emerging as a low-cost, rapid and distributed response strategy. Here we discuss how groundwater can be used strategically during and after hazard events while safeguarding long-term sustainability. Examples of earthquake, wildfire, flood and drought events in different regions highlight the potential value of temporarily using existing wells, pumps and aquifers. However, shifts in mindsets, policies and planning are urgently needed, along with interdisciplinary and equity-focused approaches that draw on disaster sociology, environmental justice, sustainability science and sociohydrology. Examples of policy direction and thought leadership from around the world show how groundwater use is emerging across diverse hazard contexts, which could be amplified by future interdisciplinary, equity-focused research.