Equity-Based Allocation Criteria for Water Deficit Periods: A Case Study in South Africa.

Managing water resources and preventing water-related disasters requires investing in tools that aid knowledge-based group decision-making at local levels. We contribute to this toolbox by demonstrating the utility of the Analytic Hierarchical Process (AHP) for establishing an expressed equity-based allocation criteria (called community weighting index) for deficit conditions. Preference for water supply during low-flow conditions in the Twee area supports the principle of proportionality and for multipurpose use. High endemism of fish species in the rivers draining the Twee sub-catchment, the socio-economic importance of farmers, the constitutional protection of the domestic water user, and the tourism sector’s importance ranking all justify the established index and revealed acceptance of proportionality. Using the AHP for community weighting can facilitate cooperative and inclusive water management decision-making while mitigating ongoing conflicts and ensuring community understanding. In the future, the results will be combined with hydrological and environmental flow estimates to determine the risk of water deficits.