Envis Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Friday, March 1, 2024

Revive wetlands to solve Delhi's water crisis: Experts







Much of Delhi's water woes could be solved if its own reservoirs are put to use. The city's 460 wetlands, along with the Yamuna floodplains and the Ridge, have enough water to help the national capital overcome a supply crisis like the current one, say hydrologists and water activists. Delhi has been facing a supply shortage of about 210 MGD because of the repair work at Munak canal in Haryana for the past few days.


The 40MW Renuka hydropower project, which is likely to supply about 437MGD for nine months (if not shared with other states), got a nod from the National Green Tribunal (NGT) earlier this month. NGT had refused to quash the environmental clearance granted to the project which was challenged by environmentalists. The forest clearance to the project is still awaited.


Water experts have pretty much written off the Renuka dam because they feel it will take a long time to come up. They say it's "sensible" to have one's own resources. "I think there are lots of governance issues. Treated water is not being reused when it should be used immediately to recharge reservoirs. Rainwater is not being harvested either when it should be taken up on a large scale in parks, commercial buildings, bridges, malls, flyovers and schools," said Himanshu Thakkar of South Asia Network on Dams, Rivers and People (SANDRP).


While rainwater harvesting is mandatory for every new house with a rooftop space of more than 100sqm, most of these norms are only on paper. There is no monitoring to check if RWH systems in residential properties are functioning because a majority of house owners do not apply for completion certificates after getting their building plans approved. When completion certificates are issued, RWH structures can be verified but no agency seems to take this responsibility.


Experts say much more water can be harvested if water bodies and floodplains are tapped immediately. "The floodplains will have to be protected from encroachments. An additional 100 MGD can be extracted from these spots through tube-wells. Water bodies should be revived by setting up a sewage treatment plant close to each one of them. Communities living near the wetlands can utilize the resource because they have a massive recharge potential," said Shashank Shekhar, professor at the department of earth sciences, DU.


Shekhar's recent assessments suggest if 400 wetlands are revived, they can provide a storage space for about 25 MGD of surface water and much more recharge, which can be utilized through groundwater extraction.


Manu Bhatnagar, principal director (natural heritage) of Intach, has recently submitted a report to the irrigation and flood control department mapping 460 water bodies in Delhi. "More than 60% of them don't have water. We have suggested that treated water be used to recharge these water bodies," he said adding that there has to be demand-side management too. "Currently the supply is based on estimates that each person consumes about 172 litres per day. We believe it can be comfortably brought down to 120 litres."


A majority of the water bodies are dry because their catchments have been encroached upon or the water channels feeding them have been stopped.




Source:  The Times of India