Technical coefficients of direct use of water in monetary terms for agriculture and urban water use

The San Francisco Integration Project is a Brazilian government project aiming to bring water to the semiarid region of the northeast. The project provides funding for two diversions of the San Francisco River, supplementing the supply of local water in four Brazilian states. The Piranhas-Açú and Jaguaribe basins will become the largest recipients of these water deliveries. In this paper, we propose methodologies to state in monetary terms the technical coefficients of water use for the economic sectors associated with urban supply (US) and agricultural irrigation (AI) in different regions of these basins. These coefficients show that for the US economic sectors, at a certain level of urbanization the productivity of water is decreasing. The coefficients of AI obtained are much lower than those of US. The coefficients of AI, when calculated by crop, showed that there is generally an inadequate crop mix in the two basins. When this is associated with the low efficiency of water use, the result is a low economic value per cubic metre of water allocated to the sector. This implies, for both sectors, a need for incentives to use water in a more efficient way.