Water allocation scenarios for public supply and irrigated agriculture in the São Francisco River integration project

Abstract

To mitigate the problems derived from the water shortage in the semi-arid northeastern region, the São Francisco River Integration Project (PISF) is being developed, transferring waters from the São Francisco River to other watersheds in the states of Pernambuco, Ceará, Rio Grande do Norte, and Paraíba. The sustainable management of these flows will be vital to guarantee their uses. This research aimed to evaluate scenarios of water allocation for public supply and irrigated agriculture, in order to assist in the management of water resources and the maintenance of these uses in the upper course of the Paraíba River (PB), East Axis of the PISF. The evaluation of multiple uses was carried out through the analysis of the permits issued for the Poções and Epitácio Pessoa reservoirs in 2019. Water allocation scenarios were undertaken considering the presence and absence of the PISF waters, based on the application of the AcquaNet model. The most significant water demands identified were, in Poções reservoir, public supply (1), and in Epitácio Pessoa reservoir, public supply (1) and irrigation (583). The water allocation scenarios showed deficits in meeting public supply and for irrigation in the simulations with and without PISF waters; however, in the scenarios involving PISF or when it provided a greater flow, these deficits were reduced. The results of this research provide information that contributes to decision-making for sustainable water management and to ensure the multiple uses of water, contributing to the improvement of the quality of life of the beneficiary population.