The Drowning Capital: Why heavy rains flood Delhi every year

Heavy rains pelted north India over the weekend, bringing several parts of the region to a halt. Visuals from waterlogged Delhi and Haryana’s Gurugram flooded social media in the past two days. More than 200 complaints of waterlogging were recorded in the National Capital on Sunday (9 July). As per Hindustan Times (HT), four people were killed in Delhi due to portions of buildings caving in or uprooted trees. Delhi chief minister Arvind Kejriwal convened a meeting today (10 July) with senior officials of the irrigation and flood control department and the Municipal Corporation of Delhi (MCD) to discuss the waterlogging issue and the rising level of the Yamuna River. After the meeting, Kejriwal said the city’s drainage systems “are not designed to take such unprecedented rain”.

Delhi received 153mm of rain on 8th & 9th July. Delhi's systems are not designed to take such unprecedented rain, so people faced troubles: Delhi CM Arvind Kejriwal pic.twitter.com/msU0I9dktc

— ANI (@ANI) July 10, 2023

How have torrential rains brought Delhi to a standstill? What’s behind the Union Territory’s waterlogging problem? Let’s take a closer look. Delhi drowns Delhi witnessed unprecedented showers, reporting 153 mm of rainfall between Saturday and Sunday morning, the highest in a 24-hour period in July since 1982, as per the India Meteorological Department (IMD).

On Sunday alone, the National Capital received 105.8 mm of rain.

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As per Indian Express, Delhi witnessed 34 per cent (258.8 mm) of the annual average of 762.3 mm in the past two days. Schools remained shut in the city on Monday owing to torrential rains over the weekend. Moderate rainfall is expected in Delhi today. The downpour resulted in waterlogged roads in the city and deep potholes in some places. Nearly 230 waterlogging incidents were reported in different parts of Delhi, including the ITO, Lajpat Nagar 1, Maharani Bagh, Majnu Ka Tilla, Rohtak Road, August Kranti Marg, Sundial Ring Road and Chanakyapuri’s Shanti Path.

#WATCH | Waterlogging and traffic jam in Delhi's ITO, after incessant rainfall pic.twitter.com/EY87pGf3fR

— ANI (@ANI) July 9, 2023

Pragati Maidan Tunnel has been temporarily closed due to waterlogging. On Sunday, the Delhi government issued a flood warning as Haryana discharged one lakh cusecs of water from the Hathnikund barrage into the Yamuna river. The Central Water Commission (CWC) warned the water level in the river in the National Capital will breach the danger mark of 205.33 metres on Tuesday. The water level in Yamuna has already crossed the danger mark, reaching 204.63 metres at 1 pm today. Kejriwal said that floods are unlikely in Delhi but the government will shift people from low-lying areas to safe spots, reported NDTV. Why do heavy rains flood Delhi? This is not the first time that waterlogged stretches in Delhi have hit the headlines. Flooding at the Minto Bridge rail underbridge in central Delhi brought traffic to a halt temporarily. On Saturday, many areas in Connaught Place were inundated with water entering shops. ALSO READ: How heavy rain is wreaking havoc across north India Whenever heavy downpour batters Delhi, it reports waterlogging. However, despite this yearly menace that leads to traffic snarls, the National Capital does not have a Drainage Master Plan. In 2011, the Delhi government tasked the Indian Institute of Technology (IIT) Delhi to come up with a drainage master plan for the city’s watershed and drainage system. As per Indian Express, IIT Delhi submitted a plan in 2018. But it was shelved by the government’s expert committee in 2021 for being “too theoretical”. The Delhi government then appointed Public Works Department (PWD) as the nodal agency for the implementation of the city’s “comprehensive” drainage master plan. [caption id=“attachment_12848802” align=“alignnone” width=“640”] Delhi witnessed 34 per cent (258.8 mm) of the annual average of 762.3 mm in the past two days. PTI[/caption] Delhi has three large drainage basins – Najafgarh, Trans-Yamuna and Barapullah. Last year, the PWD had floated tenders for the Najafgarh basin, but it failed to attract many bidders, reported Indian Express. As per the PWD, Delhi’s drains are old and designed to handle a maximum of 50mm rainfall over a 24-hour period, noted HT. If the amount of rain surpasses this level, it results in flooding of arterial roads in the city. “The issue of waterlogging can’t vanish overnight. Merely digging new drains won’t resolve the problem,” professor AK Gosain of the department of civil engineering at IIT-D, told the Times of India (TOI) last year. “We analysed all three basins of Delhi — trans-Yamuna, Barapullah and Najafgarh basins — and found each had distinct setbacks.” “In the trans-Yamuna basin, comprising parts of northeast and east Delhi and Shahdara, the majority of drains flowed west to east from the Yamuna to the eastern side of the basin against the natural east to west slope, an example of wrong planning and the cause of waterlogging. In south Delhi, the Chirag Delhi drain too is against the natural gradient from IIT Gate towards Modi Mill,” Gosain was quoted as saying by TOI.  There are also other reasons responsible for waterlogging in Delhi. Professor CR Babu, head, the Centre for Environmental Management of Degraded Ecosystems, told TOI, “Several low-lying areas that are plagued by waterlogging have actually lost their wetlands or have been concretised to an extent that their natural drainage system, or raw drains carved naturally in soil to carry water to the wetlands, has disappeared. There used to be hundreds of wetlands across Delhi. But they were neglected, levelled and built over. As a result, so many areas now become waterlogged.” The ageing drainage system and stormwater flowing into sewage networks also cause flooding. Speaking to Indian Express, senior PWD officials explained: “Pipelines are very old due to which water overflows… Stormwater drains have also been clogged by drainage over the years, as the population and unauthorised construction increased”. When asked if a new drainage plan is in the works, officials said, “Consultants have been appointed; they are expected to provide actionable solutions, along with a roadmap for implementation of engineering solutions. Consultants will also carry out an environmental impact assessment and submit a detailed report… as well as an estimate for construction work.” With inputs from agencies