Cálculo da pegada hídrica cinza no Rio Lambari: estudo de caso sobre sustentabilidade na área urbana no município de Poços de Caldas – MG

Abstract

In this study, the gray water footprint is investigated, that is, the one that refers to the non-consumptive use of water to assimilate or dilute the loads of pollutants in the Ribeirão de Poços Hydrographic Basin, which releases its sewage into the Lambari River. This study is based on consolidating the Gray Water Footprint as a representative tool for the sustainability of the water body, proving its efficiency as an environmental indicator. The estimation of the gray water footprint compared with the minimum flows of reference and with the flows observed, allowed a temporal analysis of the sustainability of the river. The calculation revealed that in several months of the year the river situation is unsustainable, the water footprint exceeded the observed flow, and this scenario has been worsening, since the water body presented decreasing flows, and a water footprint with continuous growth. The water balance of the area was calculated, and it allowed to see which months of the year have water deficit, alerting to mitigation measures and assisting in decision making, further reinforcing how much the implementation and efficiency of ETE 1 has a fundamental role to reverse the water deficit scenario of the last 8 years. It is concluded that the water management of this hydrographic basin is not efficient to guarantee the quality of its waters. The results reinforce that the water footprint is an important indicator of environmental sustainability and should be used as a tool in the search for improvements in the management of water resources in Brazil.