Potential for potable water savings by using rainwater in the residential sector of Brazil

While water availability has been decreasing all over the world, rainwater usage has been suggested to promote potable water savings and ease water availability problems. This paper describes the water availability scenario in Brazil, shows the potential for potable water savings estimated for the residential sector and proposes a new water availability indicator that takes into account the benefits of using rainwater. It is demonstrated that average water availability in Brazil amounts to about 33,000m(3) per capita per year, but it is lower than 5000 m(3) per capita per year in two out of the five geographic regions of Brazil. As for the potential for potable water savings by using rainwater, it is shown that it ranges from 48% to 100% depending on the geographic region. The new water availability indicator that is proposed shows that water availability may increase when rainwater is taken into account. (c) 2005 Elsevier Ltd. All rights reserved.