Dam break analysis of Old Aswan Dam on Nile River using HEC-RAS

The Egyptian segment of the Nile River is controlled from its upstream end by two dams: the High Aswan Dam (HAD) and the Old Aswan Dam (OAD). Nowadays, questions are being raised about the efficiency and safety of the Old Aswan Dam and what will happen if the dam fails? For this regard, a 1D hydraulic model using HEC-RAS package was developed to investigate a number of dam break scenarios, to estimate the outlet hydrograph from the dam site and to route the produced flood wave throughout the first river reach from the dam site up to Esna barrage. A numerical sensitivity analysis was performed to select the relevant values of the implicit weighting factor theta, Delta x and Delta t. Eight dam break scenarios were developed to investigate the effect of initial water level, inlet flow and dam breach width on the expected inundated area. Results showed that there would not be catastrophic consequences from the Old Aswan Dam failure. The main concern is when large flow values are released deliberately (Q = 605 mm(3)/sec) from the Aswan Dam.