Assessment of Flood Zone Reduction using Retaining Walls in HEC-RAS

Retaining walls play a crucial role in mitigating flood risks, particularly in riverine environments affected by extreme climatic events. This study evaluates the effectiveness of retaining walls in delineating flood-prone areas along a section of the Rímac River impacted by the El Niño Costero phenomenon. A two-dimensional hydrodynamic model was developed using HEC-RAS 2D, calibrated with historical data, and applied to simulate critical flood scenarios. The analysis considered the impact of a 1200-meter-long retaining wall on flood extent and river level control. The results indicate that the implementation of these structures reduced the inundated area by 72.79%, from 2.83 ha to 0.77 ha, and lowered the peak river level from 6.33 m to 4.42 m. This approach integrates hydrological and topographical data to enhance urban planning and flood risk management in vulnerable areas. Furthermore, the proposed model serves as a replicable tool for other flood-prone regions, promoting data-driven mitigation strategies based on advanced hydrodynamic simulations.