Irrigation is an essential element of agricultural production whose absence would create great economic hardship in many regions of the global South. Yet irrigated agriculture uses 70% of global fresh water withdrawals, putting major pressure on global water resources. Whilst much research has focused on technological solutions to improve irrigation efficiency, irrigation water governance arrangements remain poorly investigated. This paper examines the irrigation water governance arrangements in place in the Canale Emiliano Romagnolo (CER) district in Italy. The objective is to understand key factors driving or hindering irrigation efficiency, and to identify context-relevant policy-making dynamics that could enable greater efficiency. The analysis is conducted following the Policy Arrangement Approach, which describes a policy domain in terms of actors, rules, resources and discourses, and identifies opportunities for change in the interplay of these dimensions. Findings suggest that the existing governance arrangements have led to improvements in irrigation efficiency over the past decades in the CER district. Key factors of this performance include public financial investment in research and farm modernization, the existence of local capacity building and social capital, and the presence of a public-private organization with capacity to raise resources and to generate and transfer knowledge to both policy-makers and farmers. © 2014 IWA Publishing.