This research brief examines why water infrastructure cannot be understood through physical assets alone. Drawing on cases from Yemen, Oman, Eritrea, Libya, Sudan and beyond, it shows how allocation rules, maintenance obligations and local authority shape whether water systems function over time. It also highlights how infrastructure upgrades can unintentionally shift control over water. The brief calls for institutional assessment to be integrated into infrastructure design, funding and handover so that investments support not only functioning assets, but the systems needed to govern and maintain them.