A river basin as a common‐pool resource: A case study for the Jaguaribe basin in the semi‐arid Northeast of Brazil

This paper applies 'common-pool resource' concepts to analyse to which extent the physical characteristics of a river basin facilitate or impede good management of water in different parts of a river basin. In addition, we compare the apparent manageability of water in the different parts of the basin with the actual agricultural performance in each area. As a case study we have analysed the Jaguaribe basin in the semi-arid Northeast of Brazil. To characterize a certain location within a river basin, the term 'downstreamness' is introduced and quantitatively defined. Depending on its 'downstreamness' each municipal district in the basin is categorized in one of three topographical zones: upstream, midstream or downstream. Per topographical zone, we evaluate to which extent five specific 'conditions for good manageability' are met. These five conditions have been taken from the literature on common pool resources. It appears that three conditions are increasingly met if we go from upstream to downstream, while the other two conditions are better met if we go in upstream direction. Factors that make water better manageable downstream are the better possibilities for water storage, better predictability of water flows and the lower level of mobility of water resources. Factors that make it easier to manage upstream water resources are the small spatial extent of the allocation problem and the clearly defined boundaries of the system. In the case of the Jaguaribe basin, the net result appears to be most favourable in the midstream zone, where the advantages and disadvantages for good water management are in the best balance. As a result, the agricultural performance, measured in terms of productivity and stability of production, is best in the midstream zone of the basin.