ISSN 2375-0936
African Journal of Water Conservation and Sustainability ISSN 2375-0936 Vol. 14 (7), pp. 001-013, July, 2026. Available online at www.internationalscholarsjournals.org © International Scholars Journals
Full Length Research Paper
Assessment of the Hydraulic Performance of the Ludewa Township Distribution Network, Njombe, Tanzania
Enock W. Ngoyinde1, 2, *, Irene Trimo1, Edmund Mutayoba2
1Department of Water Supply and Sanitation Engineering, Water Institute, P.O. Box 35059, Dar es Salaam, Tanzania
2Ludewa Water Supply and Sanitation Authority; P.O. Box 4, Ludewa, Njombe-Tanzania
Abstract
Received 30 May, 2026; Revised 10 July, 2026; Accepted 12 July, 2026; Published 18 July, 2026
This paper addresses the need for locally calibrated evidence on hydraulic performance in the hilly, gravity-fed Ludewa Township distribution network, where pressure imbalance can affect service reliability and infrastructure. Field pressure measurements, utility records, GIS-supported network mapping, and EPANET simulation were combined to assess current operating conditions and identify priority intervention zones. Pressure head was used as the principal service indicator, while flow, velocity, and head loss were used as supporting diagnostic indicators. Model reliability was evaluated using 72-hour observed pressure-head series from representative nodes at upper-, middle-, and lower-elevation sites, which recorded mean pressure heads ranging from 154.52 to 172.51 m. Simulated flows ranged from 0.33 to 9.98 L/s, and velocities ranged from 0.21 to 1.26 m/s. Most nodes satisfied the adopted 10 m minimum pressure-head threshold, but the network was spatially uneven: upper and peripheral branches served by smaller-diameter pipes had lower residual margins (the operational definition of vulnerability used in this study), whereas lower-elevation zones recorded high-pressure heads that may increase leakage and pipe deterioration. Calibration and validation showed strong agreement between measured and simulated pressure heads, with validation accuracy (R² = 0.991) exceeding calibration accuracy (R² = 0.967). Model performance improved from MAE = 7.05 m, RMSE = 8.88 m, and R² = 0.967 during calibration to MAE = 3.88 m, RMSE = 4.58 m, and R² = 0.991 during validation. The results indicate that Ludewa's main hydraulic constraint is not system-wide failure but localized vulnerability and overpressure. Priority actions are targeted pipe upgrading, pressure management, leakage control, continued monitoring and scenario-based planning. These findings are based on a 72-hour monitoring window, and longer-term seasonal monitoring is recommended to strengthen confidence in generalizing the results.
Keywords: Hydraulic pressure management; EPANET, Validation, GIS; Gravity-fed network