<p>Urban areas are more susceptible to flooding because of inadequate drainage and low-permeability pavements, highlights the necessity for effective solutions that balance strength and permeability. This study addresses the issue by developing a nano-modified metakaolin-based quaternary blended concrete aimed to improve the mechanical properties and durability properties with optimum permeability properties applicable for sustainable urban flood management using metakaolin, Nano Silica (NS) and Nano Clay (NC) as a partial replacement to cement. The modified concrete mix containing metakaolin, NS and NC demonstrated significant improvement in compressive, split tensile and flexural strength by 21.6%, 40% and 14.81% in contrast to conventional concrete, attributed to enhanced microstructure and interface transition zones. The permeability coefficient and infiltration rate of the M12 mix containing metakaolin, NS and NC were found to be 44.61% and 54.91% lesser than the CC mix, as a result of matrix densification from reactive pozzolans and nano fillers. Acid resistance also enhanced, with a strength loss decrease of up to 67.64%, signifying better chemical durability. The findings concluded a strong inverse relationship between strength and permeability, showing that nano-modification effectively densifies the matrix while maintaining acceptable infiltration for drainage. Based on performance, mixes M7-M9 are recommended for sidewalks and parking areas, whereas M11-M12 are suitable for low-volume urban roads requiring higher structural strength and chemical resistance. For regions with high rainfall, the use of NS and NC is particularly beneficial to enhance durability and reduce surface wear. Overall, the quaternary blended concrete supports the development of durable, resilient, and sustainable urban drainage infrastructure, directly contributing to Sustainable Urban Flood Management objectives.</p>