The ever-expanding city of Mumbai is suffering major water shortages throughout the year. Mumbai caters to a population of approximately 14 million and the Municipal Corporation is unable to meet the water demands of this populace. The gap between demand for water and supply of water keeps increasing with each passing year. The practice of harvesting rainwater (RWH), where rain that falls on rooftops and terraces during the monsoon season is stored in tanks or is channelled into the ground to recharge the water table, is a proven, simple, economic and sustainable means of meeting household demands for water.
The overall goal of this long-term project is to introduce, promote and help install rainwater harvesting systems to Mumbai city so as to improve the living conditions and urban environment of the city. In August 2006 , CERE successfully completed a project to harvest rainwater at Malcolm Baug in Jogeshwari, Mumbai and today 175 households in five buildings of the residential colony are reaping the benefits of RWH because the usage of costly municipal water has been drastically reduced. In December 2006, borewell recharge measures were initiated in tribal villages in Dahanu Taluka by CERE. More and more urban and rural RWH projects have since been undertaken by CERE.