Gurugram, March 27 -- Groundwater levels in Gurugram have dropped sharply over the years, prompting the Municipal Corporation of Gurugram (MCG) to revive and expand rainwater harvesting systems, officials said. According to official data shared by Central Ground Water Board (CGWB), the average groundwater level has fallen from 7.57 metres in 1974 to below 30 metres now, placing the city in the "dark zone" category. Officials said the decline has started affecting supply during summers. While the Gurugram Metropolitan Development Authority (GMDA) manages supply through its Basai and Chandu water treatment plants, shortage is still reported in May and June every year. MCG officials said unregulated extraction through borewells are a major reason for depletion. Illegal RO plants and water wastage at service stations and households also add to the problem, they added. Officials said that at least 84 harvesting systems are non-functional due to the depleting groundwater level. Executive engineer Sandeep Dhundwal said that 404 existing harvesting systems are being upgraded with deeper borewells to reconnect them to the groundwater table. He added that the corporation has also planned to install 130 new modular rainwater harvesting systems across the city at a cost of around Rs.15 crore. The project is set to be completed in the upcoming three months, said Dhundwal....