Background: Urban stormwater drainage systems are historically designed based on historical rainfall intensity-duration-frequency (IDF) curves, which are increasingly rendered obsolete by climate variability.

Objective: This study aims to evaluate the hydraulic capacity of existing urban drainage networks under simulated future climate change scenarios to identify critical infrastructure vulnerabilities.

Method: This study uses a simulated dataset created for academic training purposes. The Storm Water Management Model (SWMM) was utilized to simulate rainfall-runoff dynamics for a 500-hectare urban catchment. Simulated rainfall data for baseline (2020) and future scenarios (2050 and 2080) under RCP 8.5 were inputted into the model.

Key Results: Results indicate a 22% increase in peak runoff volume by 2080. The analysis revealed that 35% of the existing secondary conduits will experience surcharging under future rainfall intensities, leading to a 40% increase in localized flooding extent.