TARIFA BINÔMIA PARA O CUSTO DA ÁGUA EM PERÍMETROS IRRIGADOS

In the irrigation districts, the variable cost tariff have being depended only on the amount of water consumed, and not in the energy and the demand for electric power to supply the water pressure and flow rate recommended by the irrigation system. The use of irrigation at lower pressures reduce the energy bill. Thus, this work propose that the water tariffs not only consider the amount of water consumed in the month, but the head, since the hydraulic power demand is a function of the product of flow rate times the head. The study compared the water cost for participants that consume the same amount monthly, but with different systems regarding the operating pressure, and simultaneity for their irrigation. The results showed that the implementation water tariff that charges the volume of water and the head may reduce the costs for the participants at low pressures up to 66%. On the other hand, high pressure participants may have their water bill increased by 133%. The simultaneity use of water also influence the cost due to variation in demand for electrical power. Therefore, it is believed that water tariffs that charges not only the volume of water consumed but the head should be implemented for a more rational use of water and energy resources in irrigated perimeters.