This study provides a technical analysis of Land Use and Land Cover (LULC) changes and their impact on stormwater runoff in Dahisar, Mumbai, India, from 2003 to 2023. Utilizing high-resolution Landsat satellite imagery processed through Remote Sensing (RS) and Geographic Information System (GIS) techniques, significant urban expansion is observed, with built-up areas increasing from 40.40% to 58.60%. Despite these changes, there was no significant increase in water bodies. The study identifies a peak stormwater discharge of 1433.44 cubic meters per second, attributed to the rise in impervious surfaces caused by urbanization. This research offers crucial insights into the challenges of rapid urbanization in coastal megacities like Mumbai, where climate change intensifies the risks associated with extreme weather events. The study highlights the urgent need for adaptive urban planning that incorporates sustainable practices, such as green infrastructure and resilient water management systems, to effectively mitigate flood risks and manage stormwater runoff. These findings are particularly significant for policymakers and urban planners, stressing the importance of addressing environmental and hydrological challenges in rapidly urbanizing coastal regions.