Assessment and Enhancement of the El‐Nasr Canal Capacity

ABSTRACT Ensuring an adequate irrigation water supply to the tail end of irrigation canals is crucial for effective water management. Rehabilitating deteriorated canals and removing obstacles are essential to improve efficiency, optimize water revenue, and ensure food security for each country. Two significant factors influencing Manning's roughness coefficient (MRC) are the growth of submerged aquatic weeds in vegetated channels and the degradation of the canal lining, resulting in increased surface roughness. These issues can lead to reduced flow velocity and discharge in open channels. The El‐Nasr Canal (NC), located west of the Nubaria Canal in the western Nile Delta, is Egypt's oldest plain concrete‐lined canal. The primary issue occurs in the third reach of the NC (Reach‐3), situated between pump stations 2 and 3. The canal cannot transmit the intended discharge in certain sections of this reach, causing the water surface to rise above the desired berm level. Therefore, a hydraulic simulation model was developed using HEC‐RAS software to simulate the water surface profile and assess the capacities of the canal sections. The study revealed that the increased MRC is the main reason for low flow velocity, ultimately leading to flooding over the berm. Based on these findings, the study recommends expanding the cross section of the canal by increasing the bed width by 6.0 m to enhance its capacity to convey the desired future discharges to the New Delta lands and reclaimed areas on the Northwestern Coast, particularly during emergencies and crop maturity periods.