Browsing by Author "Brown, Matt"

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    Real losses from drinking water networks operated by gated communities
    (Stellenbosch : Stellenbosch University, 2020-12) Brown, Matt; Jacobs, Heinz Erasmus; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.
    ENGLISH ABSTRACT: The International Water Association (IWA) has provided a standardised approach to better understand and manage water leakage and losses. Prior studies have focused predominately on quantifying the extent of water loss within municipal water networks, while neglecting relatively smaller systems operated by gated communities (GCs). Normal distribution systems are held responsible by municipal authorities as opposed to smaller, well maintained and self-managed infrastructures in GCs. The provision of added security and lifestyle improvements has seen a gradual rise in the number of GCs as more people feel the urge to relocate from freestanding properties. As part of this research, real losses in the distribution systems of three selected GCs were analysed with a focus on the minimum night flow (MNF). The first challenge was to gain access to an existing remote sensing platform, because it was beyond the scope of this research to install meters and/or a metering system. After identifying relevant collaborators, the databases had to be scrutinised in order to identify and isolate flow rates of selected GCs, with data at a sufficient resolution and a sufficiently long time series to enable analysis of night flows. Bulk meter flow rates for three suitable GCs were extracted over a 12 month time frame from a total database in excess of 35040 daily readings, linked to an existing remote sensing system. The collected data had regular intervals of 15 minutes recorded between 1 October 2018 and 30 September 2019. The ultimate data set, used for the analyses, comprised 34 944 flow rate recordings for each of the three GCs. The implementation of a stringent categorisation, selection and verification process resulted in the consolidation of a feasible data record catalogue. Research found that GC A had a current annual real loss (CARL) of 8.30 kL/d, or 21 % of the average daily consumption. The unavoidable annual real loss (UARL) component varied between 4.32 and 7.19 kL/d for the assumed average operating pressure. GC B reported a comparable CARL of 7.89 kL/d, representative of a 15 % loss. A UARL range between 4.83 and 8.06 kL/d was recorded for GC B. Lastly; GC C held a relatively higher CARL of 52 % in accordance with a 14.36 kL/d real loss. Values representative of the UARL in GC C were 6.36 to 10.60 kL/d. Research concluded that all GCs had a relatively low loss in relation to the UARL, with infrastructure leakage values. The infrastructure leakage index values for all three sites were exceptionally low for typical South African conditions. This is possibly due to better water distribution system operation and management in GCs than evident elsewhere. The research highlights several discrepancies, suggesting potential adjustments to water loss approximations for GCs, while establishing recommendations for future research.