26 Delhi flights cancelled, 15 diverted after heavy rain, thunderstorms, red alert in city

At 3 pm, the IMD updated its three-hour nowcast and placed the entire city under a red alert, indicating the possibility of further heavy downpours. Meanwhile, in western UP, Gautam Buddha Nagar, Meerut and Ghaziabad remained under an orange alert.

Rainfall in New Delhi on Monday. (Express Photo by Praveen Khanna)

Several parts of Delhi, including Sangam Vihar, Sadar Bazar, New Ashok Nagar and parts of Ghazipur in East Delhi were left waterlogged.

Officials said ongoing civic and infrastructure projects had temporarily reduced the run-off capacity along several of these stretches.

In Sangam Vihar, waterlogging occurred along an under-construction main road where the permanent stormwater drainage system is yet to be fully laid out. In Sadar Bazar, local drainage remained affected by ongoing Delhi Metro construction work.

Rainfall in New Delhi on Monday. (Express Photo by Praveen Khanna)

Janakpuri records highest rainfall

According to India Meteorological Department (IMD) officials, Janakpuri recorded the highest rainfall at 67 mm between 8.30 am and 1.15 pm.

It was followed by 57 mm at Chhatarpur, 54 mm in Faridabad, 52 mm in Gurgaon, 35 mm at Pitampura, and 29 mm at Safdarjung.

Other NCR areas received heavy rainfall: in the 24 hours ending 8.30 am Monday, the IMD station at Noorpur Choulas in Noida logged 70 mm of cumulative rainfall.

Meanwhile, Delhi’s primary weather station at Safdarjung had recorded 246.2 mm of rainfall across 12 rainy days in August, surpassing the city’s long-period average (LPA) mark of 226.8 mm for the entire month.

Rainfall in New Delhi on Monday. (Express Photo by Praveen Khanna)

Gurgaon goes under

Gurgaon was inundated after around an hour of heavy rainfall on Monday, with waterlogging reported from several parts of the city and traffic movement slowing on the Delhi-Gurugram Expressway and key roads.

The downpour caused waterlogging in Narsinghpur, Hero Honda Chowk, Rajiv Chowk, IFFCO Chowk and several areas of old Gurugram. Vehicles were stuck in water around Rajiv Chowk, while school buses and ambulances were also caught in waterlogging on Sohna Road.

The district administration said Gurgaon received 70 mm of rainfall by 1.30 pm. Key areas including Rajiv Chowk, IFFCO Chowk, Railway Road, Sector 5, Old Delhi Road, Mehrauli Road and Basai Road were heavily affected. Naharpur underpass was also waterlogged.

Rainfall in New Delhi on Monday. (Express Photo by Praveen Khanna)

Why Delhi, Gurgaon struggle with waterlogging — but Noida doesn’t

The recurrent waterlogging across the Capital is linked to its topographical challenges, urban planning experts have previously pointed out.

According to the 2018 Drainage Master Plan by IIT-Delhi, Delhi’s natural drainage system relies on its topography, with runoff flowing from the elevated south and southwest Aravalli Ridge (250-300 metres) towards the low-lying Najafgarh basin and Yamuna channel (around 205 metres).

The Capital’s stormwater has historically flowed through three primary natural drainage basins: Najafgarh, Barapullah, and Trans-Yamuna, it said.

Decades of rapid urban expansion, concretisation, encroachments and differences in the design of building drainage infrastructure have affected the city’s natural drainage system, it said, leaving low-lying areas.

Rainfall in New Delhi on Monday. (Express Photo by Praveen Khanna)

The National Capital Region (NCR), particularly Gurgaon and Noida, also sees different waterlogging situations during heavy rain, partly due to their urban planning models.

Noida was established as a planned greenfield township under the UP Industrial Area Development Act, 1976, allowing a single authority to establish a unified road grid and proportional drainage networks before private developers came in. This is why Noida sees fewer instances of waterlogging and traffic snarls in such situations.

Gurgaon, on the other hand, adopted a fragmented public-private partnership model, under which scattered land parcels were developed piecemeal, leaving internal drains poorly connected to external trunk infrastructure. Even a moderate spell of rain is enough to bring the city to a standstill.

(With PTI inputs)