Evaluating Hydraulic Performance of Two District Water Distribution Networks in Baghdad City

Abstract

This study evaluates the hydraulic performance of Baghdad's water supply network by analysing pressure heads and velocities. In this work, Water-CAD hydraulic models integrated with QGIS were utilized.  The districts 821 and 835 were selected in partnership with Al-Rashid Municipality Water Department, two districts fed from a single source, with the construction period of the two networks differing. They were calibrated in Darwin calibration using field-measured pressure at five and three locations, respectively, achieving coefficient of determination (R²) = 0.99. In District 821, pressure analysis during peak demand revealed that most junctions operated under 7 m H₂O, with 14% exhibiting negative pressure and 84% below this threshold. Velocity analysis showed that 94% of pipes-maintained velocities below 0.5 m/s, 5.6% operated between 0.5–2 m/s, and 0.5% exceeded 2 m/s. At low demand, more than half of the junctions recorded pressure heads below 7 m H₂O, while 25% exceeded this value. Velocity levels during low demand do not have considerable variations compared with peak hours usage. In district 835, all junctions recorded pressures below 7 m H₂O during peak demand, with about 50% experiencing negative pressure. Low demand analysis indicated 80 junctions operated below 7 m H₂O, while 27 exceeded this criterion. Velocity analysis revealed that 83% of pipes operated below 0.5 m/s, with the remaining 17% within 0.5–2 m/s. In conclusion, both networks predominantly operated below the acceptable pressure head of 7 m H₂O, highlighting insufficient water supply to consumers, particularly during peak demand periods.