Assessment of A Rainwater Harvesting System in A Multi-Storey Residential Building in Brazil

Abstract

This article aims to present an economic feasibility and user satisfaction analysis of a rainwater harvesting system in a multi-storey residential building (where there is rainwater to supply toilets) located in Florianópolis, southern Brazil. This research used detailed methods and also considered the opinion and habits of users regarding the use of a rainwater harvesting system. The water end-uses were estimated through questionnaire survey in each flat. The potential for potable water savings was estimated using computer simulations. Simulations were performed using the computer programme Netuno, version 4 and economic feasibility analyses were performed considering different rainwater demands. Analyses associated with the habits of the residents, the satisfaction of users and the importance of saving potable water were also carried out. Showers were responsible for the highest share (54.2%) of water consumption in the flats, followed by the other end-uses: washing machine (21.3%), kitchen tap (9.3%), toilet flush (9.2%) and washbasins (2.6%). The most economically feasible system, which presented lower payback and higher internal rate of return, corresponds to the system sized to supply rainwater only to toilet flushing. Such a system would need a rainwater tank with a capacity smaller than the capacity of the one currently in use. In general, residents expressed satisfaction regarding the rainwater harvesting system installed in the building. The study is important because, besides obtaining water end-uses in the flats, it also investigates the perception of residents related to rainwater harvesting, which has been little explored in the scientific literature.

Water Conflicts: From Ancient to Modern Times and in the Future

“…Many researchers have confirmed that rain harvesting (RH) can provide water in urban/suburban, industrial, and rural areas [107][108][109][110][111][112][113][114][115][116][117][118], promising to save freshwater, a potential that may reduce tensions and competition among users. It is considered a low health risk, cost-efficient, and an environmentally friendly technology [119][120][121], a fact that has allowed its expansion in many developing and developed countries (EU, USA, UK, Japan, South Korea, Australia, and Africa) [116].…”

Water Supply and Water Scarcity

“…Kuntz and Chisi [28] investigated the economic feasibility and user satisfaction in RWH systems in a residential building in Florianópolis (Brazil) by using a questionnaire survey. The economic feasibility analysis considered different rainwater demands, residents' habits, user satisfaction, and the importance of potable water savings.…”

“…Rainwater harvesting is an alternative water supply that can have a significant contribution in meeting future water demands and to maintain/improve the quality of water resources. It has been proven to be a cost-effective solution in urban and sub-urban areas [27,28,[90][91][92][93]. In recent years, there is a growing interest in both developing and developed countries (the EU, the USA, the United Kingdom, Japan, South Korea, Australia, and Africa) for RWH systems [27], driven mainly by their cost efficiency and potential benefits to different sectors of the economy, environment, water resources, and human health [94][95][96].…”

Design of Potential Rainwater Harvesting Structures for Environmental Adoption Measures in India

“…The sub-surface soil in opening of ridges as showed in Fig. 21 and furrows and plantation of horticulture and forest tree species (Ghisi et al 2007;Kuntz Maykot and Ghisi 2020).…”