City of Tshwane Case Study
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Economic benefit of ensuring TECHNICAL PAPER JOURNAL OF THE SOUTH AFRICAN uninterrupted water INSTITUTION OF CIVIL ENGINEERING ISSN 1021-2019 supply during prolonged Vol 61 No 4, December 2019, Pages 19–28, Paper 0469 electricity disruptions – CHRISTO POTGIETER (PrEng, MSAICE) works at Bigen in the company’s Water and Sanitation Sector. He graduated from the University of City of Tshwane case study Pretoria with a degree in Civil Engineer in 2011, obtained his BEng (Hons) degree in 2016 and completed his MEng degree in 2018 J C Potgieter, C Herold, M van Dijk, J N Bhagwan in Water Resources Engineering. Contact details: Bigen Group, PO Box 8994, Bloemfontein 9300, South Africa Mitigating the impact of electricity disruptions on water supply was investigated as a case T: +27 83 657 7504, E: [email protected] study on the City of Tshwane. This study found that current institutional arrangements Department of Civil Engineering, University of Pretoria between electricity suppliers (Eskom), water service providers and water service authorities Private Bag X20, Hatfield 0028, Pretoria, South Africa are insufficient. Therefore, a Risk Analysis and Mitigation Framework of Integrated Water DR CHRIS HEROLD (PrEng, FSAICE) specialises in and Electricity Systems, or RAMFIWES, was developed. Risks associated with water supply water resources and water quality model interruptions due to electricity disruption events were analysed. Risk categories that were development and assessment. His models have found wide practical application in catchment and addressed are short-term disruptions of less than one day, medium-term disruptions of up to a systems analysis studies that have saved South week and long-term electricity disruptions up to a month or even longer. The direct economic Africa billions of rands. He is the author of 44 benefits of ensuring uninterrupted water supply in the event of electricity disruption events technical papers published locally and overseas and is the principal author of over 130 unpublished technical reports. Chris has actively participated in over were analysed through cost versus benefit analyses. It was found that the direct benefit/cost a dozen Water Research Commission studies, most of which he has led. He ratio of supplying water during electricity disruption events is 5.6 for wet-industries and an obtained his BSc, MSc and PhD degrees at the University of the exceptional 117 for other economic sectors in Tshwane. The overall benefit/cost ratio is 15.5. Witwatersrand. He formed Umfula Wempilo Consulting in 2000. This benefit is possible at a low increase in the normal municipal bills of only 0.5%. Contact details: Umfula Wempilo Consulting PO Box 98578, Sloane Park 2152, Johannesburg, South Africa T: +27 82 459 5731, E: [email protected] INTRODUCTION Until recently in South Africa, the elec- MARCO VAN DIJK (PrEng, MSAICE) is a lecturer in The water supply sector is at the core of eco- tricity supply used in the water sector was the Department of Civil Engineering at the nomic growth and social well-being. Water considered safe, and the risk of electricity University of Pretoria (UP), and a Principal is indispensable to human survival – it is a supply failure did not play a significant role Researcher for the South African Water Research critical component required for the genera- in the design and operation of water supply Commission. He obtained a degree in Civil Engineering from UP in 1996, a BEng (Hons) in tion of power, it is required for the growing and distribution systems. Load-shedding 1998, an MEng in Water Resource Engineering in 2003, and is currently of crops and it is a basic natural resource for prompted the Water Research Commission completing his PhD. He has compiled numerous technical reports and daily existence. In the modern-day South (WRC) of South Africa in 2010 to conduct a journal publications, and has presented at various conferences in the field of pipelines, hydropower generation, and water distributions systems. He is African urban environment, without water high-level study of the effect of electricity dis- also a member of the Water Institute of Southern Africa. there will be insufficient electricity, very ruptions, specifically load-shedding, on water Contact details: little industry, no agriculture and no cities. supply (Winter 2011). The current study Department of Civil Engineering, University of Pretoria Electricity disruptions can cause water sup- (this paper), also funded and initiated by the Private Bag X20, Hatfield 0028, Pretoria, South Africa ply interruptions which will have dire social WRC, explores the implications in greater T: +27 12 420 3176, E: [email protected] and economic consequences for densely detail and takes account of new concerns that JAYANT BHAGWAN obtained a Master’s in Tropical populated urban areas (ADB 2009). have arisen since 2011. These new concerns Public Health Engineering from Leeds University, Water and electricity are intrinsi- relate to the high risk of prolonged electricity supported by degrees in Municipal and Civil Engineering. He is the Executive Manager of cally linked – the one cannot be supplied disruption events that the water supply sector Water Use and Waste Management at the South without the other. This is especially true is currently not sufficiently prepared to miti- African Water Research Commission, overseeing in South Africa where 85% of the country’s gate. In recent years there have been numer- around 150 research projects covering the management of drinking water electricity is supplied by coal power sta- ous water supply interruptions in Gauteng and wastewater in the domestic, mining and industrial sectors, with particular focus on water supply and sanitation for low-income areas. He tions (Pollet et al 2016), and urban water due to localised electricity disruptions not participated in the shaping of South Africa’s national water policy and supply, especially in-land, necessitates high- linked to scheduled load-shedding, the most legislation, and also drives the area of faecal sludge management (FSM), lift pumping systems over great distances. recent being the explosion at a City Power having pioneered an international series of FSM conferences. This link is often referred to as the Energy- substation that resulted in an electricity Contact details: Water Research Commission Water Nexus (Copeland & Carter 2017). disruption affecting Rand Water’s Eikenhof Private Bag X03, Gezina, Pretoria 0031, South Africa Electricity is used in the water sector for Pump Station (News24 2018). Subsequently, T: +27 12 761 9000, E: [email protected] pumping, treatment of raw water, distribu- large parts of Gauteng, and even parts of tion of potable water, collection and treat- North West, were affected by water supply Keywords: electricity disruptions, water supply, risk analysis, ment of wastewater, and water discharge. interruptions. This electricity disruption was load shedding Potgieter JC, Herold C, Van Dijk M, Bhagwan JN. Economic benefit of ensuring uninterrupted water supply during prolonged electricity disruptions – City of Tshwane case study. J. S. Afr. Inst. Civ. Eng. 2019:61(4), Art. #0469, 10 pages. http://dx.doi.org/10.17159/2309-8775/2019/v61n4a2 19 Risk Analysis and Mitigation Framework of Integrated Water and Electricity Systems (RAMFIWES) Test RAMFIWES on Electricity Water service Water service Tshwane case study suppliers providers authorities • Define scope • Identify hazards Risk analysis Risk analysis Risk analysis • Estimate risks Document risk analysis • Risk acceptance criteria • Compare risks with criteria Risk evaluation Risk evaluation Risk evaluation Risk assessment • Identify risk reduction options • Gather relevant data • Cost vs benefit analysis Document risk Risk mitigation Risk mitigation Risk mitigation Risk • Make decisions mitigation mitigation • Implement decisions • Consider the outcome of the Continuous Continuous Continuous risk analysis and mitigation Report development development development • DRMP focuses on water and Review of Disaster Risk of Disaster Risk of Disaster Risk electricity risks Communicate Management Management Management • Should be incorporated into Improve programme Disaster risk Disaster risk management Programme Programme Programme existing DRMP if this exists Figure 1 RAMFIWES outline and testing it on the City of Tshwane case study dealt with relatively quickly due to the nature Q Review current institutional arrange- a duration of less than one day). There is of the electricity disruption event. If the event ments in place to mitigate the risk. a lack of preparation for medium- to long- had been more severe, there would have been Q Propose institutional guidelines (pertain- term duration electricity disruption events. longer-duration water supply interruptions. ing to system management, operation Therefore, medium- to long-term duration To put the risk of water supply interrup- and design principles) for electricity sup- electricity disruption events pose a high tions due to electricity disruption events into pliers, Water Service Providers (WSPs) risk for Tshwane, from both economic and context: Rand Water’s current Number 1 and Water Service Authorities (WASs). public well-being points of view. strategic risk on its list of Top 10 Strategic This study found that the current institution- No guidelines, frameworks or government Risks, published in its 2017 Annual Report, al arrangements of South Africa’s electricity policies to aid electricity