Contribution of Maintenance Management Practices on Non - Revenue Water Collection. A Case Study of DAWASA Kibaha Region

Abstract

Water utilities in many African countries, including Tanzania, face a persistent challenge of high levels of non-revenue water (NRW) surpassing the recommended limit of 15%. This issue is primarily attributed to a poor maintenance management system for water distribution networks. In Sub-Saharan Africa, the NRW value often exceeds 23%. Specifically, the Dar es Salaam Water Supply and Sanitation Authority (DAWASA), a public utility, experiences a staggering NRW rate of 37%, surpassing the required limit of 20%. This implies that DAWASA loses a significant amount of revenue, approximately Tsh 10.5 Billion, on a monthly basis due to non-revenue water. The main objective of this study is to assess the impact of maintenance management practices on reducing non-revenue water in the water distribution network. The specific objectives are to identify the factors affecting the current maintenance management practices in the non-revenue water distribution network, determine the extent to which these factors contribute to non-revenue water, and develop strategies to improve the current maintenance management system for non-revenue water distribution network. By enhancing maintenance management practices in the water distribution network, the study aims to increase availability performance and customer satisfaction while reducing non-revenue water. The study will be conducted in Kibaha District, focusing on various water distribution installations within the Pwani Region. A case study research design will be employed, with a sample size of 80 selected through purposive sampling technique. The study identified several factors influencing maintenance management practices in the water distribution network, including material vulnerability, lack of pipe and fittings, human activities (construction works), network duration, construction technology practices, material quality, water meter quality, water meter duration, technology, water project design practices, human resources, limited maintenance budget, and water pressure. To assess the extent of these factors' contribution to non-revenue water, the Relative Importance Index (RII) was used. Material vulnerability emerged as a key contributor to non-revenue water, with a relatively high RII of 0.805. This indicates that the susceptibility of materials used in the water system significantly influences water losses.