A conceptual index for benchmarking intermittent water supply in a water distribution system zone

Various challenges, such as limited freshwater resources, climate change impacts, rapid population growth, urbanisation and underinvestment in water supply infrastructure, have led to intermittent water supply (IWS) in potable water distribution systems. Earlier research has confirmed that IWS negatively impacts the consumers, the infrastructure and the water supply authorities. Water supply authorities need tools to help understand IWS and the associated implications. A new indexing framework involving the causes and impacts associated with IWS is presented in this paper. In addition, a novel approach allows for quantification of the severity of IWS based on knowledge of a few readily available inputs. The severity quantification is based on two ratios: the intermittency ratio is a temporal measurement, accounting for supply duration; the connection ratio describes spatial aspects, using the number of service connections affected. The indexing framework and quantification tool could lead to improved understanding of IWS and could assist water supply authorities faced with IWS to make informed decisions. Improved planning of remedial actions to mitigate or avoid risks associated with IWS is aided. The tools presented in this paper could be used as basis for future development of a key performance indicator.Keywords: intermittent water supply, index, water scarcit

A new structure for discharge measurement in sediment laden rivers

Thesis (M. Ing.) -- University of Stellenbosch, 1997.One copy microfiche.Full text to be digitised and attached to bibliographic record

Intermittent water supply: a South African perspective

The prevalence of intermittent water supply in South Africa was investigated in this research study. Data on intermittent water supply in South Africa was collated by considering the following four sources: a targeted water services provider survey; published databases and related reports; open-access publications, such as online media articles; and field visits by the project team to selected areas. The data were spatially and temporally analysed to determine the prevalence of intermittent water supply. The population affected by intermittent water supply increased by ~26% between 2008 and 2017, which exceeds the population increase of ~12% over the same period. Moreover, 22 million people in South Africa were affected by intermittent water supply in 2017. Results from this study confirm an increased prevalence of intermittent water supply over time and show that 65 of the 231 municipalities in South Africa supplied water intermittently, 32 had continuous water supply and 134 had no data. Fundamentally, the outcomes highlight the widespread occurrence of intermittent water supply in South Africa, which is in line with the poor state of water services delivery in South Africa, as portrayed in the 2018 National Water and Sanitation Master Plan by the national Department of Water and Sanitation

Supplementary household water sources to augment potable municipal supply in South Africa

CITATION: Nel, N., Jacobs, H. E., Loubser, C. & Du Plessis, K. 2017. Supplementary household water sources to augment potable municipal supply in South Africa. Water SA, 43(4):553-562, doi:10.4314/wsa.v43i4.03.The original publication is available at http://www.wrc.org.zaENGLISH ABSTRACT: This paper addresses on-site supplementary household water sources with a focus on groundwater abstraction, rainwater harvesting and greywater reuse as available non-potable water sources to residential consumers. An end-use model is presented and used to assess the theoretical impact of household water sources on potable water demand in formal residential areas. Reliable potable municipal supply to urban consumers via the water distribution system is typically linked to relatively low uptake of household water sources. However, stringent water restrictions in some large South African cities that prohibit outdoor use, and reports of intermittent water supply, have led to increased uptake of household sources in South Africa. This paper describes the legal position regarding such sources in South Africa, and describes an end-use model to assess the theoretical impact on water demand in formal residential areas. The model provides valuable strategic direction and indicates a significant theoretical reduction in potable municipal water demand of between 55% and 69% for relatively large properties when household sources are maximally utilised (when compared to exclusive unrestricted municipal use as a baseline). This load reduction on piped reticulation systems could be an advantage in order to augment municipal supply, but water service planning and demand management are complicated by the introduction, and possible future decommissioning, of any household water source. The extent of both positive and negative impacts of household water sources requires further research.Publisher's versio

Supplementary household water sources to augment potable municipal supply in South Africa

This paper addresses on-site supplementary household water sources with a focus on groundwater abstraction, rainwater harvesting and greywater reuse as available non-potable water sources to residential consumers. An end-use model is presented and used to assess the theoretical impact of household water sources on potable water demand in formal residential areas. Reliable potable municipal supply to urban consumers via the water distribution system is typically linked to relatively low uptake of household water sources. However, stringent water restrictions in some large South African cities that prohibit outdoor use, and reports of intermittent water supply, have led to increased uptake of household sources in South Africa. This paper describes the legal position regarding such sources in South Africa, and describes an end-use model to assess the theoretical impact on water demand in formal residential areas. The model provides valuable strategic direction and indicates a significant theoretical reduction in potable municipal water demand of between 55% and 69% for relatively large properties when household sources are maximally utilised (when compared to exclusive unrestricted municipal use as a baseline). This load reduction on piped reticulation systems could be an advantage in order to augment municipal supply, but water service planning and demand management are complicated by the introduction, and possible future decommissioning, of any household water source. The extent of both positive and negative impacts of household water sources requires further research