The Yamuna river enters Delhi at Narela village, located on the border of Haryana, and then makes a 48-km journey before exiting in the southeast. The Palla floodplain runs across 20-25 km of the river’s length north of Wazirabad. What is remarkable about this floodplain, as of all the floodplains of our monsoon rivers, is that it contains aquifers that are perennial sources of drinking water to our cities. These aquifers are natural water storage and recharge centres. As long as less water is withdrawn than is recharged, this resource can last forever.
Given that 365 districts in 17 states are currently facing drought, it would have been common sense for governments – in states and at the Centre — to look after our aquifers. However, the National Capital Region lost the Yamuna floodplain aquifer four years ago through thanks to exploitation and uncontrolled sand-mining. As the water level in the aquifer dropped, the Yamuna’s polluted waters and the Hindon rivers entered the aquifer, destroying a water source that had provided good quality water to Noida for over 30 years. Noida has now had to fall back on the overdrawn Ganga for most of its supply.
Vikram Soni, a physicist at the University of California, Santa Barbara, together with a group of researchers recently found the Palla floodplain aquifer contained a replenishable yield of 80-100 million cubic meters per year – or 57.9 million gallons per day – provided it wouldn’t get polluted or become overexploited. So Soni devised a scheme called ‘Conserve and Use’ to tap the floodplain aquifer and provide drinking water for one million Delhiites.
From the start, the emphasis was to ensure only so much water is withdrawn that the groundwater level in the aquifer does not fall below that of the contaminated Yamuna. To ensure this, sensors to measure groundwater levels would need to be placed and monitored in the wells from where the water is withdrawn.
After some R&D and testing, the Delhi Jal Board (DJB) asked WAPCOS, a public sector company, to prepare a detailed project report. Supervised by Soni, WAPCOS recommended that the city install a computerised SCADA system to keep a check on water levels. The estimated cost of the project was Rs 10 crore.
The first phase of this project, to be completed in ten months, would supply 40 million gallons per day, worth Rs 600 crore at rates charged by water tankers. The second phase requires the city to install a new pipeline with 50-60 million gallons per day capacity.
After a few hiccups, the Delhi government restarted the project in 2016, but it couldn’t progress at full steam because the city’s old pipeline could not handle a higher quantity of water. Nonetheless, ‘Conserve and Use’ already supplies 20 million gallons of quality drinking water per day for almost one million people.
The situation isn’t likely to improve, however, thanks to frequent changes in the Delhi government’s ministry of water and DJB officials being transferred. When Soni visited the Palla floodplain in mid-March this year, he was shocked to find farmers in the neighbourhood growing water-intensive crops such as wheat and strawberries in winter and spring, and even basmati rice in the pre-monsoon season. Water-intensive agriculture is supposed to be prohibited in this protected biodiversity zone.
When such large quantities of water of withdrawn, “we are likely to lose the entire aquifer once and for all,” Soni said. He has sent a letter to Chief Minister Arvind Kejriwal expressing his concern.
“The other major problem is the villages in this area are routing their sewage into nearby depressions on the floodplain,” he continued. “Seepage of sewage water will contaminate the yet pristine aquifer and this can be regulated by placing [sewage treatment plants] with the recycled water flowing into the river or to the Najafgarh drain.”
If this wasn’t bad enough, the Delhi government isn’t aware of the ecological limits of this project. Earlier this year, Kejriwal announced that his government was planning to set up 70 more borewells and Ranney wells in this area to further draw over 15 million gallons a day. And inexplicably, he announced this without consulting any of the experts who had helped put the ‘Conserve and Use’ project together. As a result, some water activists have warned that groundwater levels in and around Narela have already fallen below 60 feet.
This in turn means that the aquifer level in the Palla floodplain could have dropped below Yamuna, exposing it to polluted river water. In fact, the aquifer could already be polluted, and the Delhi government is none the wiser about it. The situation is precarious, and unless the government is prepared to walk a tight line managing this living, fragile resource, it could go the way of the Noida aquifer.
“It is important that we adhere to ecological limits while exploiting any natural resource of this kind, so that these vital lifelines are protected for future generations, too,” Diwan Singh, a water activist who has worked on these aquifers, said. “Cities must develop with caution” regarding the use of their natural resources, “or it could lead to an urban collapse, which seems imminent in the case of Delhi.”
Rashme Sehgal is an author and a freelance journalist based in Delhi.