While Delhi Jal Board officials have claimed they have no RWH data on private buildings and residential settlements, most public compounds have no means of conserving rainwater or have obsolete harvest pits clogged with mud, stones and horticultural waste.
At Vikas Bhawan at ITO, which is run by the Public Works Department, an official shook his head. “There is no rainwater harvesting system here. Rainwater is channeled through the drains outside. If there is a system, we don’t know,” the official said. This when the Delhi government in 2019 ordered all departments to install RWH systems in their buildings. Even after strenuous efforts by the government, the technology has not been widely adopted.
According to the standards of the Department of Urban Development, all buildings constructed from 2001 on 100 square meters or more must have an RWH system. But there are visible shortcomings everywhere. At a Delhi public school on Deendayal Upadhyay Marg, the entry point to the collection pit was littered with rubbish and choked with mud. At the AIIMS roundabout, the runoff system from the flyover network had large boulders and horticultural waste clogging the water conduit.
At the Nelson Mandela Marg shopping complex, pit entry points were clogged with construction debris. Sonia Ghosh, environmental activist and resident of Vasant Kunj, said: “Three groundwater pits have been dug, but we don’t know if they are still functional. She added that the pit to channel rainwater harvested into the shopping complex was now topped by a taxi rank and had never been cleaned.
Many RWAs also said the same, recalling plans years ago to adopt rainwater harvesting and plans that never took off. As BS Vohra, President of the East Delhi Federation of RWAs, a group of 100 RWAs, said, “In 2012, there was an initiative to install a rainwater harvesting system in our locality. About five pits were dug in the parks, but they were never maintained. Currently, several RWAs in Delhi have done nothing to conserve rainwater. We’ve written to the Delhi government about this, but we haven’t heard from anyone yet.
While rainwater harvesting is one of the key parts of the Delhi government’s plan to provide clean drinking water to people around the clock in three years, the 2022-23 state budget admitted that the RWH had not yet grown in size.
According to the Delhi Economic Survey 2021-22, DJB has implemented RWH in 594 water utility facilities. Harvesting systems have also been installed in 3,687 of Delhi’s 4,778 schools. In 413 schools, CEP devices are being built, while work is due to start in 449 establishments.
However, there is no mention in the survey of private sector adoption of the technology and things are not moving at the desired pace there.
An assessment by Sushmita Sengupta, deputy program manager (water) of the Center for Science and Environment, quantified that a rainfall of 118.4mm would generate around 87,000 million liters of water in the city for harvesting . “There is huge potential for rainwater harvesting in Delhi. But rooftop harvesting isn’t the only requirement. Ponds and lakes need maintenance to be able to recharge groundwater,” Sengupta pointed out. DJB officials, however, argued that there was no data on the potential for rainwater conservation in Delhi.
In 2021, according to India’s Meteorological Department, Delhi recorded a record annual rainfall of 1,526mm at Safdarjung Base Weather Station, the highest in 121 years. But all that water is usually not saved, said water expert Rajendra Singh. “The downside is the lack of follow-up. And then there is also corruption. Thus, houses obtain building permission without incorporating RWH. Delhi will only earn the moral right to fight other states for water when it learns how to conserve rainwater itself,” Singh said.
Singh also noted that Delhi’s underground aquifers were 78% overexploited, with extraction continuing even when inflows were low.
Despite repeated attempts to get comment on building maintenance and steps taken to implement the state government’s rainwater harvesting ordinance, there was no response from DJB. On his part, an NDMC official said, “In the areas of New Delhi, steps are being taken to install water harvesting plants on the roofs of all buildings and parks under the jurisdiction of the civic body.” .