Gerenciamento da demanda de água: proposta de alternativas na escala de uma cidade.

Abstract

The Brazilian's Northeast, in special, comes feeling the disastrous effect of the combination of successive droughts to the deficiency or, even though, absence of water resources management. Inside of this context, Campina Grande city, Paraiba, was chosen as case study. During its history, this city was marked by crises in its supplying system. Traditionally, the reply standard for the problems of water scarcity it comes being the adoption of strategies directed to the water supplies expansion. However, the expansion of water supplies model comes i f showing unsustainable due to continuous reduction of the water availabilities, difficulty to find new sources and high involved costs. It is standed out, therefore, the necessity to adopt a new paradigm based on the context of the water demand management (GDA) associated to water supplies expansion, whose concept has left of the premise of that great part of the future water demand is taken care of with the reduction of wastefulnesses. Inside of this optics, this research supplies subsidies to the managers when of the elaboration of a program of water rational use of residential and public sectors of the Campina Grande city. In these kinds of programs, the technological alternatives of GDA have been pointed as most viable, a time that allow the reduction in the water consumption without it has significant changes in the users habits. Through the scenes simulation that had contemplated the hypothetical implementation of the technological alternatives selected in this research (low-discharge devices and sub-metering), it was verified possibility to reduce the water demand significantly, as much for the residential sector how much for the public sector (Alcides Carneiro University Hospital - HUAC). In the residential sector case, for example, the water consumption reduction indices had varied between 1,20 and 33,64%. The adoption of only one toilet bowl with 6 liters for drive gives a water consumption reduction of 14,50% for the Campina Grande residential sector. Considering this situation, the initial investment reaches the amount of R$ 170,00 and period of return of 14 months for a residence with monthly average consumption of 20 m3. In the HUAC, the substitution of the conventional devices for more economics ones resulted In a water consumption reduction index around 24,89%. In this case, the return of the initial investment reaches 12 months.