<p>Accurate prediction of bedload transport is crucial for designing hydraulic structures in sediment-prone, data-scarce regions, such as the Moroccan Al Haouz region. This study develops and validates an integrated predictive modeling framework to quantify sediment flux and deposition height for a 100-year flood at a road-stream crossing on the El Bahja River. The approach uses a chain of tools, including HEC-HMS, HEC-RAS, ArcGIS, and an S-shaped granulometric model, to calibrate and compare twelve well-known sediment transport equations, ensuring robust and accurate predictions. Validation against field measurements confirms the framework’s reliability and identifies six models (Parker and Klingeman, Camenen and Larson, Ribberink, Smart and Jaeggi, Watanabe, and Meyer-Peter and Müller) that employ a threshold-based methodology. These models estimate a specific sediment discharge of 0.14 m³ s⁻¹ m⁻¹ and an accumulation level of 1.01 m, closely matching field data. The primary novelty of this work is the integrated validation of a multi-model framework under extreme conditions, an approach that is seldom documented. The key practical outcome is a robust selection framework for the most reliable sediment transport equations, supporting informed model selection for resilient infrastructure design in the High Atlas and comparable semi-arid regions, thereby advancing Sustainable Development Goal 6 (Clean Water and Sanitation).</p>