Water end-uses and rainwater harvesting: a case study in Brazil

This study investigates the potential for potable water savings by using rainwater in a home in Blumenau, southern Brazil. The water end-uses were estimated based on frequency and time of use of the water appliances. The water flow rates were measured using containers and a stopwatch. Besides the estimated water consumption, daily measurements were taken using a water meter. The water consumption estimated was compared with the consumption measured and the water end-uses were obtained. The water for activities that did not require potable water accounted for 46.5%. This percentage was used as input data in the Netuno computer programme along with other parameters for the design of a rainwater harvesting system. The use of rainwater in the house, using a 2,000-litre tank, would provide potable water savings equal to 44.8%. This study demonstrated that there is a great potential for the use of rainwater in single-family houses in Blumenau.