Why Yamuna floods Delhi – a story of missed warning bells

An interim report by a central govt. appointed committee, which is yet to be made public, reiterates many issues which have been raised in the past too by courts and activists

Flood water flows through Vikas Marg in ITO area, in New Delhi on July 15, 2023. Delhi witnessed one of its worst floods last year forcing over 25,000 people to move to relief camps. | Photo Credit: Sushil Kumar Verma

Nine months after Delhi witnessed its biggest ever floods – which forced over 25,000 people living on the banks of the Yamuna into relief camps and wrecked damage worth crores of rupees – nothing much has changed on the ground with two months for the next monsoon and possibly another flood.

After Yamuna swelled and inundated many parts of the city, including Raj Ghat and reached the Supreme Court’s gates, in July last year, experts had said that permanent constructions encroaching on the river’s floodplain was one of the main reasons for the intensity of the flood Delhi witnessed, although there was heavy rainfall upstream of Delhi. Encroachments destroy the water holding capacity of floodplains and also constricts the area of flow of the river.

Ground visits, documents, and interviews with officials reveal that lessons have not been learnt from the past and the fragile ecosystem of the floodplain continues to me meddled with.

After last year’s devastating flood, two committees were formed to find out what led to the unprecedented flood and suggest solutions: One committee by the Union Ministry of Jal Sakti (MoJS) and another by the Irrigation and Flood Control Department of the Delhi government.

Other main observations from the interim report of the committee appointed by the MoJS

All gates of the ITO Barrage should be opened during the monsoon. There should be regular maintenance of equipment. (The ITO Barrage at the heart of Delhi had become a political flashpoint between the Delhi and Haryana governments last year during the floods, as the latter operates it and five of the gates were found to be shut and had to cut open by the Delhi government.)

There is discrepancy in the data on discharge of water during the floods from different barrages on Yamuna. “The amount of water released from Hathnikund barrage in Haryana (up stream of Delhi) and at Okhla Barrage in Delhi should have been somewhat the same. But the committee found huge difference in this data,” a source said.

Raise parts of existing embankments on both sides of the river at different locations in Delhi, including Mahatma Gandhi Marg near Raj Ghat, Geeta Colony, Alipur, among other places.

But both the committees are yet to submit their final reports.

Before last year’s flood, the biggest flood Delhi had witnessed was in 1978, when floodwaters reached the Delhi University and Model Town. After the 1978 flood, a ‘Yamuna Standing Committee’ in 1979, decided that “minimum spacing between future embankments on the (opposite) banks of the river Yamuna should be 5 km” and the embankments should be at a minimum distance of 600 m from the “active” edge of the river.

Both measures were aimed to protect the floodplains.

But 35 years later, a National Green Tribunal (NGT)-appointed committee observed in a 2014 report that “unfortunately” the decision was not followed and the maximum distance between the two embankments of the river Yamuna was – less than 2 km – and “hence the floodwater carrying capacity of the river has been greatly compromised”.

The flood Delhi witnessed last year was also due to ignoring various warning bells like this report and missing multiple deadlines set by courts for action over the years.

By 2023, the distance between embankments on opposite sides of the river – which is mostly considered as the floodplains – was down to just a few hundred meters at many points. Floodplains in some cases extent beyond the embankments too.

The committee set up by the MoJS has submitted an interim report to the Ministry in January this year, but it is yet to be released in the public domain, a central government official confirmed The Hindu.

“The report has mentioned that high rainfall from July 9 – 13, 2023, in the upper reaches of Delhi, was the main reason behind the flood,” the official said. “But it also reiterated the long-standing issue of encroachments of the floodplains which aggravated the flood.” This is important because, when Yamuna’s level kept rising through July 10 – 13, Delhi witnessed only light scattered rain.

The committee found illegal encroachments and even noted that after some official constructions on the floodplain such as bridges, temporary structures were not removed from the river bed and it caused increased afflux of water, the official added. “The report mentions that construction of new embankments and bridges across Yamuna, which encroaches the floodplains, also resulted in the higher level of water in Delhi,” the official added.

Sadly, many of these issues have been raised in the past too by courts and activists.

“After the report was submitted, no action has yet been taken based on it,” the official said. A source in the Delhi government said that the second committee has also submitted an interim report, but refused to divulge any information. This report is also not available in the public domain.

Yamuna flows through Delhi for about 54 kilometres and leaves floodplains spanning nearly 9,700 hectares, a lot of which have already been lost to development and encroachment. Experts warn that climate change could lead to more erratic and intense rainfalls, triggering stronger floods, and floodplains will have a larger role to play in flood mitigation in the future.

In this series The Hindu explores different aspects of what plagues the floodplains and why Delhi continues to flood.