The October–December rainfall is crucial for Chennai's water supply, as it replenishes reservoirs and groundwater levels. However, the intense spells of rain during this period can lead to urban flooding, particularly in low-lying areas. The variability in rainfall from year to year, influenced by weather systems such as low-pressure areas, depressions, and cyclones over the Bay of Bengal, poses challenges for flood management and water resource planning. Heavy downpours can disrupt daily life, damage infrastructure, and impact transportation in the city.