Code to produce the figures in the paper, whose abstract is the following: Traditional irrigation systems sustain millions of people worldwide and are increasingly targeted by modernisation policies aiming at enhancing their water and crop production efficiencies. While modernisation may be desirable in some cases, most frameworks are blind to three relevant pillars that have kept these systems adaptive through contrasting social and climatic contexts: their functional diversity, their capacity to foster belonging and the traditional knowledge of irrigators. Drawing on a collaboration between Spanish traditional irrigators and scholars and on an extensive corpus of interviews, we argue that these attributes cannot be collapsed into efficiency metrics and cannot be rebuilt once lost. Modernisation must be reframed to ensure that traditional irrigation systems transition to new configurations without losing the social and ecological fabric that underpins them.