Flood risk assessment in developing regions is often constrained by the absence of locally derived depth–damage functions, limiting the reliability of loss estimation and risk-informed planning. This study proposes an integrated methodology that combines the Source–Pathway–Receptor–Consequence (SPRC) framework with socio-economic indicators to assess fluvial flood risk in the Shotorak catchment, Qazvin Province, Iran. In the absence of local damage data, European Commission depth–damage curves were applied to hydraulic simulation outputs for 25- and 100-year return period flood events. The modelling results indicate maximum flood depths of 5.85 m and 11.02 m, with inundation extents of 29.79 ha and 45.67 ha, respectively. Residential land in Mohammadieh was affected over 3.4 ha under the 25-year scenario and 5.9 ha under the 100-year scenario, while agricultural land in Sharifieh experienced the greatest losses, increasing from 12.5 ha to 17.4 ha. Residential risk increased by 52% between the two scenarios, underscoring the exposure of expanding urban settlements. The findings reveal pronounced spatial variability in flood impact, driven by the interplay of topography, land use, and socio-economic conditions. Overall, the proposed framework offers a transferable and practical interim tool for flood risk screening and risk-sensitive planning in regions where local depth–damage functions are unavailable.