Appraisal of Socio-Technical Water Loss Control Strategies Using Cost-Benefit Analysis in a Water Supply Network

Abstract

The authors conducted a socio-technical cost–benefit analysis (CBA) in Alexandra Township (Alex for short) by combining three water loss control investment strategies: (i) pipeline and infrastructure upgrades, (ii) repair and maintenance, and (iii) socio-domestic retrofitting capital. The researchers performed the CBA using sensitivity analysis methodologies such as marginal cost of capital (MCC), weighted average cost of capital (WACC), coefficient of variance (CV), the net present value (NPV) ratio, and cumulative and total cost methods. The findings for socio-domestic retrofitting capital investment showed that at an average investment cost of USD 5735 per household, consumption was reduced from 1369.4 m3/year to 301.99 m3/year, whereas a projected water savings average of 521.05 m3/household/year was achieved. The results show that the cumulative cost of water losses equaled USD 43.9 million per year, and that, if the water loss trend continues beyond the year 2026, almost 100% of the system input volume (SIV) will be non-revenue water (NRW) in the water balance. Using the MCC method, the integrated results for the socio-technical strategy showed that the economic level of leakage (ELL) was achieved at a WACC of 16.2, a CV of 0.66, and an NPV ratio or net capital risk of 0.246. This study demonstrates that the socio-technical approach is a viable alternative for water loss control and may be adopted in various parts of the world.