10 water bodies at Asola Bhatti to store 80mn litres, recharge groundwater table

New Delhi
In a bid to recharge the groundwater table, Delhi’s forest and wildlife department has created 10 water bodies at south Delhi’s Asola Bhatti Wildlife Sanctuary over the past nine months to collectively store around 80 million litres of water, officials aware of the development said.
They said that the water bodies have been created at topographically strategic locations where water naturally accumulates.
“Work began in November (2023) to construct these water bodies and by June, had been completed. These water bodies began to fill up as soon as monsoon arrived and all 10 water bodies are now filled. The elevation of the area, along with the contouring done, means any rainwater that would otherwise go to waste earlier is now diverted to these water bodies,” a senior forest official in the south division, requesting anonymity, said.
In Delhi, most districts are either tagged “semi-critical” or “over-exploited” by the Central Groundwater Board (CGWB). In 2018, CGWB submitted to the Supreme Court that 15% of the groundwater in the Capital was at a depth of more than 40 metres or lower and parts of south and southwest Delhi were the most impacted, with water being found as deep as 80 metres below ground level.
The creation of these 10 water bodies has also been shared by the Central Pollution Control Board (CPCB) in a report to the National Green Tribunal (NGT). CPCB inspected Asola in June, on NGT orders seeking details of the revival of water bodies in Delhi, including at the sanctuary.
“The source of water of all 10 water bodies is rainwater and no artificial filling or recharge is proposed. No concrete construction has been used in the 10 water bodies. Stone pitching will be used to stabilise the banks, along with doob grass and plantation or shrubs,” CPCB said in its report dated August 23.
Onkar Chauhan, a forest department official who worked on the creation of these water bodies and is also a geographic information system (GIS) analyst and draughtsman, said a contour survey and geomorphological study of the area was done last summer to assess areas where water would accumulate. Historical data was also assessed to identify possible streams, he said.
“We did a stream order analysis last year, both pre-monsoon and after monsoon. Waterlogging was also assessed in urban areas around the sanctuary to see if water could be diverted from there to these water bodies. The Delhi Parks and Gardens Society (DPGS) did a physical demarcation of these water bodies after that and we began work in November. Digging work was completed by March and now, plantation is being done in the vicinity,” Chauhan said.
The department said the average depth of 10 water bodies, all of which were carved out at Sahoorpur, Satbari and Maidangarhi, is around three metres and the average area is 0.9 acres. Four each have been created at Satbari and Sahoorpur, while two have been created at Maidangarhi.
“The water bodies are nearly an acre in size. The largest water body is spread across 1.21 acres at Sahoorpur and the smallest is around 0.68 acres, at Satbari,” the forest official, on condition of anonymity, said.
Over time, the official said they also plan to assess the impact of water bodies in terms of groundwater recharge.
Diwan Singh, an environmental activist who has played a key role in reviving water bodies in Dwarka, said around 30% to 40% of the rainwater that accumulates here is likely to percolate through and help recharge the groundwater table. “Within 100 metres of the water body, we can see an increase of up to 1 metre in the groundwater table every year. This is a good move by the forest department, but they must ensure no water from surrounding neighbourhood areas is diverted to these water bodies as there is a high risk of sewage also entering through stormwater drains, ultimately leading to contamination,” Singh said.