A decision-support approach for improving the strategic management of collective irrigation schemes in the Brazilian Nordeste

Abstract

The management of collective irrigation schemes raises complex issues regarding water management and choice of water pricing. Several approaches have been suggested to tackle these issues, such as systemic analysis or participatory appraisal methods. This paper shows how an approach based on management sciences and intervention-research was used with the Maniçoba scheme in the Petrolina-Juazeiro area. This case is characterized by a management transfer from a parastatal agency to a water users association called district. This newly-established manager has faced major uncertainties that put the scheme viability at risk. Perennial crops have progressively replaced annual crops, altering farmers' water demand. Both payment defaults and an inadequate water pricing system impact on the district financial balance. The approach aims at helping the scheme manager address strategic issues rather than make mere daily operation adjustments. Based on a conceptual framework of collective irrigation scheme management, it focuses on: (i) interactions between water supply and demand; and (ii) choice of water pricing system. In both cases simulation tools have been developed to support prospective reflection by simulating and comparing alternative scenarios. WADI calculates the water supply-demand ratio according to changes in hydraulic infrastructure and water management rules, while a second spreadsheet program calculates the impact of water pricing on farmers' incomes and managers' budget. Various ways of improving the small-scale farmers' water supply were compared, e.g. by implementing night irrigation and individual reservoirs. Alternative water pricing systems were simulated in order to increase the managers' revenues and to secure coverage of their fixed expenses. It included optional contracts adjusted to different farm types. A role playing game was then organized to improve the stakeholders' understanding and to stimulate discussions regarding the choice and the payment of water pricing. This approach provides a relevant framework both to understand current scheme operation and to support stakeholders' prospective reflection. But it needs further research regarding the assessment of their assumed learning processes.