Résumé
Quantification of states, corporations, nature or self has become pervasive in the past 40 years. The water world's struggles are rife with, and shaped by, numbers, indicators, metrics and models. This review explores how the production, promotion and use of 'water numbers' conceals deeply political processes, hypotheses, worldviews, intents, old habits and new fashions. Whether embodied in scientific or expert practices, or in indicators, thresholds, water accounts or cost-benefit analyses, water numbers promote specific values and interests; they also obfuscate complexity, heterogeneities and uncertainties, they manufacture legitimacy and authority, and they act as control devices to shape behaviour. We offer a more detailed analysis of water indicators that describe water scarcity, ecological status, progress towards SDG 6, and embody New Public Management principles. We end with a call for critical water studies to more forcefully engage with these debates, in line with the centrality of quantification in water management and policy.