The atmospheric temperature globally has risen during the last few centuries, causing global warming and climate dynamics. The impact of global warming has caused environmental effects that include increased rainfall intensity, which is recognised as the leading cause of flooding, and destruction and devastation to the surrounding environment, infrastructure, and human life. Road stormwater drainage systems are used for removing and controlling excess runoff water to the right way. However, regardless of enhanced technologies, the reliability of drainage system schemes remains a major undertaking for water and hydraulic engineers alike. In this study, a thorough evaluation of the methods employed in previous studies and research on rainfall forecasting models was undertaken. Further to that, the effect resulting from climate change on structures of drainage infrastructure is considered in addition to the methods to enhance drainage system challenges with recent models developed for advanced drainage and waterway requirements that need to be designed in consideration of climate change.

Road drainage systems are often-constructed utilised design approaches not incorporating process-based depictions of possible hydrological responses, resulting in insufficient systems due to infrastructural development and climate change and ultimately, increased hydrological reaction. This study assessed possible effects of precipitation intensity variation following future severe rainfall events on the current road drainage system as whether pre-climatic stormwater drainage system could withstand potentially higher discharges and the need for modified design guidelines incorporating possible precipitation intensity variations due to climate change. A case study was undertaken utilising rainfall data to develop an intensity-duration-frequency (IDF) curve representing precipitation volume variations due to climate change. The peak discharge and water level were simulated using hydraulic software program SWMM 5.1 for the existing open drainage system, wherein three future potential climate scenarios, namely 2030, 2040, and 2050 were simulated based on the RCP4.5 and RCP8.5 scenarios. The simulation results showed a tremendous future precipitation increment for RCP4.5 and RCP8.5 scenarios, yielding the following values, respectively: 28.8%, 43.7% and 34.6% and 65%, 61.5% and 75.5%. Therefore, the study findings and approach implemented should be considered when detailing assessments and preserving areas are at risk of high water flows. The study concludes that the existing road drainage system's inadequacy to manage copious rainfall amounts anticipated due to climate change. Therefore, the study contributes to suggest the need for developing drainage system magnitude using higher return periods to mitigate flood levels on urban road networks.