Browsing by Author "Van der Walt, Johannes Tinus"

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    Development of a sustainability index for South African dwellings incorporating green roofs, rainwater harvesting and greywater re-use
    (Stellenbosch : Stellenbosch University, 2012-03) Van der Walt, Johannes Tinus; Jacobs, H. E.; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.
    ENGLISH ABSTRACT: South African water service providers experience major problems with providing adequate water services to consumers. Water service providers in South African urban areas rely on traditional centralised infrastructure, such as bulk supply networks, to provide water services. Alternative supply and stormwater drainage methods should be encouraged to help mitigate these problems. The researcher thus aims to quantify the potential impact that three alternative methods may have on a given dwelling in terms of its dependence on traditional bulk water services. The three alternatives considered in this thesis are the construction of green roofs, rainwater harvesting and greywater re-use. An efficiency of dwelling water use index (EDWI) was developed during this research project. It was designed in such a way as to show what portion of municipal water services could be replaced within the given dwelling by using the proposed techniques. The final EDWI-rating is obtained by using the EDWI-software tool developed as a part of this research. The derived EDWI-rating ranges from 0 to 100, with a rating of 100 indicating a dwelling requiring only the removal of a portion of sewage by a municipality, but no external water supply. Such a dwelling would also not require any water from a municipal network to meet domestic demand and all stormwater from its roof would be utilised within the plot boundaries. Results presented in this thesis illustrate how different geographical regions require different system specifications to obtain optimal EDWI-ratings, thereby lowering their dependence on the respective municipal water services. Validation of the EDWI-system proved difficult as no similar index could be found during the literature review. It was therefore decided to benchmark the EDWI-system using three model dwellings with nine configurations producing a total of 27 analyses. The EDWI-system provides a conceptual foundation for sustainable water services to South African households in serviced urban areas. Future work could further improve the EDWI-system by testing its practical application so that it may be extended to act as a national barometer, used to compare decentralised water services in terms of sustainability.