Rainfall is one of the most complex phenomena occurring on earth to study with extreme and advanced soft computing engine that can perform well with adaptive perception. Here, in this study, an attempt has been made to study the behaviour of rainfall in Chennai district, Tamil Nadu, India, using wavelet tool. Wavelet is one of the prominent tools for analysing the data in various ways. One such technique called multiresolution wavelet analysis is implemented here to study the pattern of rainfall in Chennai. This approach applied to the data works well for and can be implemented for complex data. The above approach fits not only to simple data but also for complex data. Rainfall data from 2001 to 2017 have been taken into account for studying the pattern. The influence of change due to groundwater is investigated in different criteria, and future threats posed by climate change are also analysed. The key factors involved in understanding climate change and hydrological regime of groundwater were identified, and the residents of the Chennai locality could plan for better management methodologies, especially for those who are residing in coastal regions of the district. Better management methodologies with recommendations are suggested to attain sustainability in groundwater resources. The research was carried out based on sustainable groundwater managements for 12th plan, submitted to planning commission of India. The reports state that in 2004, 28% of India’s blocks were showing alarmingly high levels of groundwater use.