Abstract: The accelerated and disorganized deforestation in Central Brazil and the transformation of these natural ecosystems into crop land or pastures, without adequate technologies, resulted in irrecoverable damages to the environment, especially with respect to water and soil conservation, with particular mention to compactation. As a consequence, the soil intake rate decreased and surface runoff increased, thus causing laminar erosion, low soil quality, silting up of rivers, floods and decreased sustainability of family properties. With the objective of reverting this scenario, a demonstrative unit was implemented in Sete Lagoas MG, in 1995, in a property of 70 ha, where 30 micro-cachments ("barraginhas") were built to contain surface runoff damages.These micro-cachtments also retain pollution sources carried by the waters and favor the recharge of good quality water tables, by means of improving soil intake rate, recovering water sources and alleviating droughts. Due to the success of this demonstration unit, by means of field visits by farmers, NGO´s and publication of articles in journals and national/international congresses, a decision was taken to extend the experience and build 960 low-cost micro-catchments, in 1998, in 60 small properties covering all the micro-basin of the Paiol stream, in the village/community of Estiva, Sete Lagoas county. That was only possible because of the active participation of small farmers in the indication of existing degraded sites and the support provided in terms of food and lodging for the working teams As a result, it is now possible to hear the farmers testimonials on the effects observed in elevation of water tables observed in their domestic reservoirs ("cisternas"), better utilization of the water and drought alleviation, that have increased their yields.

No presente trabalho, utilizaram-se os Sistemas de Informações Geográficas para desenvolver uma metodologia a fim de identificar seções do curso de água de sub-bacias com potencial para construção de reservatórios, como também, simular um reservatório capaz de atender à demanda de abastecimento de água na cidade de Viçosa – MG, em 2030. O estudo foi desenvolvido na sub-bacia do rio Turvo Sujo, bacia do rio Doce. O modelo digital de elevação hidrologicamente consistente (MDEHC) foi obtido com dados de altimetria e hidrografia do IBGE (Instituto Brasileiro de Geografia e Estatística). Identificaram-se nove seções com estreitamento menor que 100 m. Na simulação do reservatório para atender a demanda de água para Viçosa, em 2030, foram realizadas visitas a campo em quatro seções, corroborando os resultados encontrados com a utilização da metodologia. | The Geografical Information Systems was used in this study in order to develop a method for the identification of sections in the watercourse of sub-basin with potential for reservoir construction, and to simulate a reservoir able to meet water supply needed for the city of Viçosa, Minas Gerais state, in the year 2030. The study was carried out in the sub-basin of Turvo river, of Doce river basin. The hydrologically consistent digital model (MDEHC) was developed by altimetry data and hydrography obtained from Instituto Brasileiro de Geografia e Estatística. Nine sections with less than 100m narrowing were identified. The results from field visit to four sections validated the current simulation methodology for reservoir that could meet water demand of Viçosa in 2030.