The Canal lining is usually used to decrease seepage loss and raise water transport efficiency. Traditional unlined irrigation canals often suffer from significant water loss due to leakage and low water levels, negatively impacting hydraulic performance and irrigation efficiency. Despite the widespread use of irrigation canal lining, there have been few studies to evaluate the effect of different lining types in controlling seepage under varying conditions. This paper focuses on assessing the effect of two different types of concrete lining and concrete quilt on improving the hydraulic performance of the Bani Hassan irrigation canal. A one-dimensional steady-state hydraulic model was created using HEC-RAS version 6.6 software to simulate flow distribution in the canal. In this model, the hydraulic calculations are derived from a one-dimensional energy equation between the canal cross-section, relying on the canal geometry and the manning roughness coefficient. Thus, the software iteratively processes the water surface. The Manning’s roughness coefficient for the concrete surface was calibrated using the root mean square error (RMSE) method. Seepage losses through the canal section were then calculated based on Darcy’s law for both pre-lining and post-lining conditions. The results showed that unlined canal sections recorded seepage losses of 4,546 m³/day, whilst concrete quilt lining reduced these losses to 599 m³/day (≈92% reduction) and concrete lining to 588 m³/day (≈95% reduction). The contribution of this study lies in analyzing the hydraulic efficiency of Iraqi irrigation systems represented by the Bani Hassan Canal, lined with concrete versus concrete quilt under identical conditions, using hydraulic modeling and seepage rate estimation to assess changes in efficiency.
