Humanitarian management of drought needs better water security data.

Droughts are a primary driver of humanitarian crises in arid regions, yet early warning systems that index humanitarian financing often omit water security data in favour of food security monitoring. Based on 42 expert interviews assessing management barriers and information needs during the 2020-24 drought in the Horn of Africa, resulting in an estimated 71,100 excess deaths in Somalia alone, we find water security data to be critical in shifting management to proactive mechanisms. Monitoring of water availability (such as water quality and groundwater/surface water levels) and water access (such as water prices and household surveys) is needed to design solutions that proactively mitigate water shortages and their secondary impacts on food security (such as through borehole rehabilitation, alternative water supplies, and cash transfers). Furthermore, if causal relations between water and food insecurity are analysed, the cost-benefit basis for financing water supply interventions can be more completely propositioned, and food insecurity hotspots can be better anticipated.