Elevated corridors such as the Western Peripheral Expressway are among the key factors disrupting Delhi’s natural water flow and drainage systems, according to the newly unveiled Drainage Master Plan 2025. The report recommends that water-sensitive studies be made mandatory before executing major infrastructure projects to prevent obstruction of natural drainage patterns.

The Drainage Master Plan 2025, designed as a 30-year solution to the Capital’s chronic waterlogging and flooding problems, divides Delhi into three drainage basins — Najafgarh, Barapullah, and Trans-Yamuna. Prepared by consultants appointed by the Public Works Department (PWD), the plan identifies infrastructure-induced disruptions as a significant challenge to Delhi’s drainage capacity.

The consultants have also developed Detailed Project Reports (DPRs) for each basin, outlining current challenges and recommending actionable solutions. The report highlights that projects meant to ease congestion and improve connectivity — including the 135-kilometre Western Peripheral Expressway — have altered regional water flow patterns, particularly within the Najafgarh Basin, extending beyond Delhi’s National Capital Territory (NCT).

Constructed to reduce traffic and air pollution, the expressway has unintentionally impacted natural drainage, creating flow obstructions that exacerbate flooding in several low-lying areas. The report cautions that similar issues could arise with future projects, such as the proposed elevated Ring Road and the expansion of the Delhi Metro, if drainage integration is overlooked.

A senior PWD official noted, “While feasibility, soil, and environmental studies are routinely conducted before any construction project, water-sensitive assessments are often neglected. The findings of this plan make it clear that such studies are essential for mitigating flood risks.”

The report underscores that drainage considerations must be integrated into the design of all major urban projects. It further warns that upcoming proposals — such as the construction of a ring railway along peripheral roads — could further alter flow patterns, restricting water entry into Delhi to only a few designated points.

With Delhi’s population projected to reach 30.8 million, urbanisation pressures, particularly in the western and northern regions within the Najafgarh Basin, are expected to worsen the city’s flooding risks.

The proposed elevated Ring Road, spanning 56 kilometres over the existing Mahatma Gandhi Marg, will pass through major junctions including Nigambodh Ghat, AIIMS, Ashram, Sarai Kale Khan, Punjabi Bagh, and Lajpat Nagar. Including ramps, loops, and connecting roads, the total length of the corridor could reach 80 kilometres, significantly transforming the city’s transport landscape.

However, the report stresses that the expansion must be guided by “water-sensitive spatial planning” and blue–green infrastructure principles, promoting resilient and sustainable urban development.