RECARGA ARTIFICIAL DE AQÜÍFEROS FRATURADOS NO DISTRITO FEDERAL: UMA FERRAMENTA PARA A GESTÃO DOS RECURSOS HÍDRICOS

Abstract

This research was developed in the Alto da Boa Vista condominium area,where is expected the occupation of about 20,000inhabitants, in an area of 6.9 km�. Such condominium is located inan important region of natural recharge of one of the most importantaquifers of the Parano� Aquifer System in the Federal District. About3.8 km� will be sealed, due to paved roads, roofs, and will causea loss of 35.5% in the natural recharge of the porous aquifers, and56% of the fractured underlying aquifers. The water public supplyplanned to this area is based on the groundwater exploitation of twelvedeep wells. Considering the total area of the basins and theconsumption of water in the region, if the total area is occupied,the water demand of the condominium alone would be twice therecharge of the fractured aquifer. This situation will certainly causean excessive exploitation, comprising the sustainability and thewater resources. However, the climatic conditions of region are favorableto the utilization of rainwater, captured on the roofs of theresidences and carried to infiltration, to provide the recharge ofthe fractured aquifers in the area. In this context, two techniquesofartificial recharge were applied and tested, using experimental systemand rainwater. The rainwater captured by roof gutters wascarried to four different types of cylindrical dug wells for rechargein the soil (indirect system) and to a deep injection well (directsystem). Based on precipitation simulations, experimental tests andin a comparison of hydrologic water budgets, and consideringdifferent conditions of urbanization of the area, it was possibleto evaluate the efficiency of the two systems. The best systemevaluated was that presented by a cylindrical dug well filled withquartz gravel. This system can compensate the decrease ofinfiltration due to surface sealing and can help the sustainabilityof public water supply by aquifer exploration. The application ofthese techniques of artificial recharge is an important toll to waterresources management.