Development of a Maintenance Management Model for the Water Distribution Network to Enhance Water Availability

The majority of water distribution networks in developing countries suffer from chronic water scarcity and high non-revenue water (NRW), largely due to inefficient maintenance processes. This study addresses this critical issue by developing and testing a proactive Maintenance Management Model for the North Mwika, Tanzania water supply network, which, despite sufficient raw water capacity, has a 47% NRW level. With an explanatory sequential mixed-methods design, questionnaires, focus group discussions, and document reviews were employed in data gathering from 50 stakeholders, engineers, technicians, and members of the community. The Relative Importance Index (RII) analysis indicated that the leading technical factors impeding performance were sediment blockages (RII=1.000), valve faults (RII=0.996), and network design deficiencies (RII=0.984), while tight budgets and slow response times were the foremost operational constraints. Regression analysis testified to the strong negative impact of these technical conditions (e.g., sediment clogging, B=-0.210, p=0.000) and positive contribution of adequate resources (e.g., budget, B=+0.095, p=0.010) on water availability. The predictive model developed was highly accurate, with 96% agreement between predicted and actual water reliability in five network zones. The study concludes that a paradigm shift is needed from reactive to proactive, data-driven maintenance. It suggests an integrated model of prioritised infrastructure rehabilitation, guaranteed funding for preventive maintenance, institutional capacity building, and greater community participation to successfully reduce NRW, improve water availability, and ensure the long-term sustainability of the water supply system.