Abstract
Availability of sufficient quantity of potable water is an essential human requirement. However, water utilities are having problems to supply water through the network system without losing considerable amount of water. The volume of loss is shockingly increasing. Every year more than 32 billion cubic meters do not reach the client through leakages from distribution networks around the world. A further 16 billion cubic meters is dispatched to consumers but not accounted because of theft, poor metering, inadequate billing system or illicit use. South Africa, like any country, is facing water losses in its distribution system. The situation is worsening with South Africa being the 30th driest country in the world and confronted with challenges due to limited energy resources. The aim of this study is to explore real water loss in water distribution networks within the Tshwane Metropolitan City in South Africa and suggest methods to better identify and reduce the loss. Water balance components provided by the water supply coverage of the city and the resulting performance indicators determine the quantity and the types of water loss. The results of these two components are then assessed against the water networks characteristics (pipe’s material, diameter and age, connection status, pressure applied) to identify the causes of water loss. The last step of the process is to suggest ways to reduce the loss and recommend upgrading of the municipality water supply infrastructure or improvement of management system. It is found that the city of Tshwane water facilities is providing enough water for the population at the right pressure, with acceptable losses between 23.0 and 27.8%, but increasing every year. 80% of losses are physical. The Infrastructure leakage index is 5 to 6 times the expected minimum leakage. 63% of pipe materials used are PVC with 37% of risks of failure. 50% of pipes in the city are more than 20 years old, increasing the risks of leakage.
In order to improve the efficiency of the water facilities, it is suggested to implement active leak control, ensure proper maintenance and efficient renewal plan, pressure management intervention in some areas and amplify staff training programme for water technicians. Future research may focus on apparent losses, specific areas with high level of water loss or assess the system after the implementation of specific interventions.