Physical Water-Supply Infrastructure in Pastoral Drylands in Ethiopia, Kenya and Somalia: A Rapid Evidence and Gap Map

Abstract Physical water supply infrastructure such as boreholes, wells, pans and piped schemes plays a fundamental role within the pastoral systems of the horn of Africa. However, information regarding their impact on outcomes such as conflict, mobility, rangeland and equity can be difficult to find in the literature. A rapid evidence and gap map was created using English language studies between 1990 and November 2026. This identified 259 physical water supply studies in the pastoral and agropastoral drylands in Ethiopia, Kenya and Somalia. After triaging these studies, 82 were shortlisted. Of these, 59 unique studies met the inclusion criteria. These were categorized by country, publication, study design, water supply type and outcome. The majority of studies focused on Kenya (n = 31) and Ethiopia (n = 24) with a small number from Somalia (n = 6). Most studies were from 2025 and 2026 (n = 17) with the outcomes of supply (n = 31) and governance (n = 18) being reported most frequently. Only a few studies focused on conflict (n = 6). Of these, a small number were single site (n = 2), some were purposively sampled (n = 1), but none compared sites with and without water supply, nor were they longitudinal. The highest number of studies were focused on supply of boreholes and wells (n = 10). A minimal number of studies were reported on sand dams and rainwater harvesting (n = 3) and equity (n = 5). Within these three countries there are no studies providing evidence to whether water supply infrastructure increase or reduce conflict using a testing method. Only continental studies have an event design.