The Role of Water Availability in Mitigating Heat-Related Mortality: Empirical Evidence from South Africa

Predictions of rising global temperatures over the next century necessitate the evaluation of interventions against heat-related mortality. In developing economies where household-level adaptations such as installing air conditioning may be unfeasible, community-level interventions are necessary. In this paper, I demonstrate a significant mitigating effect of water availability on heat-related mortality by exploiting daily variation in the number of deaths, weather, and volumetric river flow rates at key reservoirs and sanitation facilities in South Africa. I show that this effect is driven by the primary water source in each population subgroup, suggesting that increasing the supply of piped water and expanding access in poor and rural areas can insulate households from negative shocks to the water supply from natural sources. This demonstrates the importance of investment in water infrastructure and technologies to increase the supply of potable water as a tool in the fight against climate change.