How to improve inhabitants' acceptance of rainwater harvesting systems? Application to an existing collective residence in northern Algeria

In Algeria, at the present time, there are no rainwater harvesting systems (RWHS) registered with the public authorities as an alternative to the public water supply. This is explained by numerous factors, the most important being inhabitants? acceptance. The aim of this article is to investigate the current level of acceptance of an RWHS as a viable method for backing up the public water supply system. Our hypothesis is that inhabitants? acceptance can be improved by the increasing awareness of the benefits of an RWHS. For the purposes of this study, an RWHS located in northern Algeria was designed, and its benefits were measured and discussed with the direct participation of residents living in the building. The first benefit was the potential potable water saving (PPWS) and the second was the benefit-cost ratio (BCR). The PPWS was estimated at 51 m3/year. The BCR was estimated at 7% (15% with local council funding). This paper shows that, in the case of an existing building, inhabitant acceptance of an RWHS depends on three factors: (1) the amount of rainwater delivered by the RWHS; (2) the cost of building and managing it; and (3) the extent of the modifications made to the building.