IntroductionPractically all rivers are subject to morphological changes due to the dynamics of flow and sediment transport (Matsuda 2004). Alluvial rivers experience a frequent alteration in planform and cross-section due to the simultaneous sedimentation and erosion processes (Church 2006). River morphology and hydrology are recognized as essential elements for integrative studies that seek to develop an understanding of river behaviour to boost river management scenarios (Sear et al. 1995).The stability of a river channel over a certain period is controlled primarily by the flow and sediment regimes. If any of these driving factors experience a sudden or a prolonged change, the river channel responds by changing its morphology (Pollock et al. 2014). Alluvial river channels frequently display a three-dimensional morphodynamic alteration in the aspects of river channel planform. The morphology of an alluvial river channel is the consequence of deposition and erosion processes in the river. Morphological changes are affected mainly by the amount and calibre of the sediment passing through the channel. Alluvial river channels are formed due to the transported and deposited sediments passing through the channel. Accordingly, the channel is self-formed (Church 2006).The Nile River is the main source of water in Egypt. Nile River is known for its morphological changes related to alterations in the water flow regime (Farag et al. 2021). The Nile River travels 927 km from Aswan High Dam (AHD) till it reaches Nile Delta afterward it emerges into two branches; the Damietta branch towards the east and the Rosetta branch towards the west. Rosetta branch is approximately 240 km in length starting from Delta Barrage till it reaches its promontory on the Mediterranean Sea.The flow in the Nile River is controlled by (AHD) southern Egypt. (AHD) construction on the Nile River in the year 1964 altered the flow and sediment regime along the Nile River. The most common effect of dams is flattening the hydrograph curve of the flow passing through the downstream. Sediment transport is also affected as large amounts of sediment are trapped, releasing only a fragment of the trapped load into the river channel. Flow discharge passing through the Rosetta branch before AHD construction could reach 600 million m3/day, and about 220 million m3/day after AHD construction. Suspended sediment load concentration at El Gafaraa gauge Station on Nile River downstream the AHD decreased from 3800 ppm before the construction of the dam to 50 ppm after the dam construction as the total sediment load was decreased by a percentage of 98% (Shalash 1980).Conveyance capacity is described as the ability of a river channel to convey a specified flow of water (Venczel 2008). Maximum conveyance capacity is the amount of flow that a channel can convey before overtopping. Flow conveyance is the discharge conveyed through a given channel segment for a given stage. Modifications to the channel geometry or factors affecting the water velocity will modify how flow is conveyed through the channel. An important challenge in estimating conveyance capacity is how to account for the complexities of real rivers taking into account their shape, depth, length, sinuosity, meandering, and roughness, and the capability to represent them in numerical models (Samuels et al. 2002).(Venczel 2008) declared that the main type of factors affecting river conveyance capacity is “Instream factors”. The “Instream factors” refer to direct changes to the channel planform that affect the conveyance capacity of a river. These instream changes can be summarized as follows; Revetment structures, channel shape, flow velocity, meander cut-offs, dredging operations, locks, dams, levees, and human encroachment.Efforts to restore the conveyance capacity and flow regime of rivers across the world have caught huge attention due to the remarkable morphodynamic changes in natural channels. Dredging operations are the removal of the topsoil from the river bed. Dredging operations are considered a solution to increase the conveyance capacity of any river by offering a direct impact on river conveyance capacity in a short duration as the results are immediate but also has many disadvantages as it is considered a temporary solution demanding frequent dredging operations, lowering the surface water profile, and have a high operations cost.Numerical modeling is essential in evaluating river morphological changes. The conveyance capacity of the western branch at Warrak island in the River Nile, Egypt was investigated in a study by (Salama et al. 2020) using a two-dimensional numerical model. The study evaluated current conveyance capacity and proposed various scenarios to increase the flow conveyance of the study area mainly depending on dredging operations and removing the unmanaged human intervention at the island. Their study showed that dredging to a safe navigation elevation increased the conveyance capacity of the western branch of the island from 31.4% to 45.5%. (Enas 2021) used a two-dimensional numerical model to assess dredging operations’ impact on navigability of the second reach of the Nile River. Results revealed that dredging operations alone cannot be adopted as a permanent solution for river navigation bottlenecks as the riverbed returns to its original form within 10 years. (Magdy 2021) also used a two-dimensional numerical model to assess dredging operations as a solution for some navigation bottlenecks in the third reach of the Nile River with results proving that dredging can be a suitable solution.The main objective of this study is to estimate the maximum conveyance capacity of the Rosetta branch. Analyze morphological changes that occurred during a period of 17 years starting from the year 2003 to 2020 using a two-dimensional numerical model, conducting hydrological and inundated land analysis, proposing three rehabilitation scenarios to increase Rosetta branch maximum conveyance capacity, and assessing each scenario’s impact on surface water profile, stream velocity, and inundated lands related to different flow discharge scenarios.