For Delhi’s survival, let Yamuna be a river again

Even during the monsoon, the Yamuna rarely floods these days. And only when it does, it looks like a river. But the spectacle of vigorous flow and wider span is short-lived. As soon as the water recedes, the river goes back to being a drain.

columns Updated: Aug 06, 2018 19:01 IST
Shivani Singh
Shivani Singh
Hindustan Times
Delhi,yamuna,yamuna in Delhi
People swim across the swollen Yamuna river, in New Delhi on Sunday, July 29, 2018. (PTI)

Ten-year-old Aryaman Bharadwaj was taken aback when he saw water swirling under the Nizamuddin Bridge last week. As he wondered whatever happened to the stinky drain he had always seen there, his father couldn’t help but compliment the river by tweeting: “Delhi’s swollen #Yamuna looks like a calm #Brahmaputra.”

Such overwhelming reactions were not surprising from citizens who had rarely seen the Yamuna in spate. In fact, most of the new residents of Delhi, including Aryaman’s father who arrived in the national capital 18 years ago, have always known the Yamuna to be an oversized toxic sewer.

Even during the monsoon, the Yamuna rarely floods these days. And only when it does, it looks like a river. The surplus rainwater from the upstream allows it to reclaim the floodplains. But the spectacle of vigorous flow and wider span is short-lived. As soon as the water recedes, the river goes back to being a drain.

That the river needs fresh water to live is native wisdom. We go against this natural principle to meet our ever-increasing demand for irrigation and drinking water. We hold the river in the barrages upstream and divert it into canals, leaving only a trickle to flow downstream.

To make it worse, we throw much of the city’s untreated toilet and industrial waste into the river. We also clutter the riverbed, which is the lung to the river and the biggest aquifer the city can ever have, by building vast concrete structures right on the floodplains.

Despite all the hardware commissioned to treat the city’s wastewater, the sewage treatment plants remain grossly underutilised. As much as 45% of Delhi’s habitation is not even connected to the network. Their wastewater lands into stormwater drains that empty out into the Yamuna, which has no water to dilute these toxins.

“We are told that the Aviralta (uninterrupted flow) in the river will follow Nirmalta (purity). But the two go together,” explains Manoj Misra, a river activist who petitioned the NGT in the ongoing case on the cleaning of the Yamuna.

A flowing river not only cleanses itself naturally, it also carries along sediments, life forms and energy that conserve local biodiversity. A study by environmentalists Vikram Soni, Shashank Shekhar and Diwan Singh in 2014 found that to perform these functions and recharge the aquifers, the Yamuna in Delhi needed at least 50–60% of its natural flow throughout the year. However, only 32% of the natural annual flow was allowed in the river at the time of the study. During the non-monsoon months, it dropped to a meagre 16%.

While experts insist on a minimum perennial flow during all seasons, the government has proposed to build a dam upstream to store water during monsoon and release it during the lean months. While the court is examining the proposal, Misra points out that the monsoon is the only time when a river recharges the aquifers, which in turn feed the river for the rest of the year.

The Yamuna with its sand aquifer that runs two km wide and nearly 40 metres deep along the 48-km stretch in Delhi is the city’s best non-invasive storage of fresh water. “As much as 100 MGD can be extracted from it sustainably if the floodplains are maintained well. So why would you need a dam?” asks Diwan Singh.

Today, Delhi draws from the Yamuna to support over 40% of its 913 MGD water supply. No river can survive such extraction for too long. To channel more freshwater into the river, both Delhi and Haryana need to be on the same page, which will require a great deal of political will. Haryana itself can save water by encouraging farmers to give up water-intensive crops and engage in efficient irrigation techniques. To save its lifeline, Delhi must fix the basics:

  • • Delhi’s water policy estimates that the city can capture 140 MGD from rainwater runoffs alone. Right now, it just flows down the drain.
  • • Delhi needs to revive its natural water bodies, which met much of the local water requirement across the city till not so long ago.
  • • Delhi must cut down on leakages and pilferage. As much as 30% of Delhi’s treated water is wasted in distribution, while the National Water Policy says only 15% is acceptable.
  • • To beat the waste-and-want dynamics, Delhi has to reduce consumption and invest in recycling. Under the water policy, the capital must increase its recycled wastewater use to 70% by 2023 and at least 80% by 2026 to meet its non-drinking requirements. Even today, the city’s affluent rather criminally use drinking water to flush toilets, wash cars and water lawns.

Delhi’s future hinges on the survival of the river that has nourished it for centuries. The Yamuna is still the city’s best bet for long-term water security.

Only if we stop sucking it dry.

First Published: Aug 06, 2018 14:05 IST