PROPOSAL FOR RAINWATER HARVESTING SISTEM FOR A SCHOLAR INSTITUTE IN NORTHEAST REGION OF BRAZIL: A STUDY OF THE ECONOMIC VIABILITY

Abstract

The expectation of drinking water shortage for the next years has been a motivating factor to search for alternatives to supply the demand of future generations, to promote rational use of water and to reduce its waste. Once water is directly linked to people’s maintenance and quality of life, and also compromise all living species in our planet, it is imperative that the entire civil, business and industrial societies, as well as the government and its public institutions, to seek mechanism to preserve it. In this context, this paper aimed to propose a system of rainwater usage for Campina Grande campus of the Federal Institute of Education, Science and Technology of Paraíba – IFPB, and analyze the economic viability of its establishment. To meet the increasing demand of water, we considered the rainfall in the region, and the potential to capture rainwater in that campus, which has been designed in a reservoir of 787 m³, the method Rippl. The proposed system aims at supplying 94% of non-potable consumption of that campus, which will provide a savings of 84% of water purchased from the Water Company of Paraíba - Cagepa, and based on the tools of financial mathematics, represents a relationship benefit /cost of 2.52 with Capital Return Period of 9.83 years. Therefore, the economic viability of the rainwater harvesting system implementation was proved and it showed to be attractive, especially when it requires a very high demand of water with less noble purposes, as it is the case.

Key words: economic viability, rainwater harvesting, water usages.