A continuum of governance regimes: A new perspective on co-management in irrigation systems

•A new classification for state-, community- and co-managed irrigation systems is proposed.•Co-management is operationalized in a detailed way.•Distinction of co-management patterns can be expressed along a continuum.•Performance of a large number of irrigation systems (n = 244) is measured across several dimensions.•Successful community-based management is not confined to small irrigation systems.