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Research Publications (Academic Support)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/211

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Subject: search.filters.subject.Water quality

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    Integrating quality and cost of surface raw water : upper and middle Vaal water management areas South Africa
    (IWA Publishing, 2010) Dzwairo, Bloodless; Otieno, Fredrick Alfred O.
    The user-pays principle encourages use of a water tariff structure that incorporates pollution and/or depletion of a water resource because that water represents a capital resource base. Development of a tool that models variability of surface raw water quality in order to predict cost of treatment thus makes economic sense. This paper forms the backbone for an on-going doctoral study in South Africa's Upper and Middle Vaal Water Management Areas (U&MVWMAs) of the Vaal River (VR). Specific objectives of the overall research are; to carry out pollutant tracer hydrochemistry of specific reaches of the U&MVWMAs including producing an integrated ecological functionality for the whole study area, and to develop a tool that models the variability of surface raw water quality using surface raw water tariffs and water quality data for years 2003–2008. This paper concluded that downstream water boards (WBs) paid a higher water resources management charge (WRMC) for more polluted raw water than upstream WBs. It was recommended that a quality-cost model be incorporated at tier1 of the cost chain for water services to ensure fairness of service delivery and spread of burden to consumers.
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    Ecological functionality of the Upper and Middle Vaal Water Management areas
    (2012-12-05) Dzwairo, Bloodless; Otieno, Fredrick Alfred O.; Ochieng, George M.
    A harmonised in-stream water quality guideline was constructed for the Upper and Middle Vaal Water Management Areas (WMAs) using ideal catchment background values for the sub-catchments; Vaal dam, Vaal barrage, Klip River and Blesbokspruit/Suikerbosrant Rivers. Data for years 2003 to 2009 was interpolated to a daily time-step for 2526 days at 21 monitoring sites covering both WMAs. Conductivity was used as a surrogate to capture the variability in water quality. This provided an ecological functionality model of the study area, coded for ranges 10-18, 19-45, 46-80, 80< and 81-100 mS/m. The Upper and Middle Vaal basin is currently extremely vulnerable to changes in water quality, uncertainty about changes which it can tolerate, and the fact that there are very limited options for mitigating effects of poor water quality in the basin, overall. Thus a precautionary approach is being proposed in this paper, in order to protect the ecological functionality of the aquatic ecosystem. The proposed harmonised guideline presents a crucial model to pre-determine the ecological functionality for any water point in the study area, in order to provide upstream-downstream pollution trading and other decision support processes towards sustainable basin management