Behind Delhi’s waterlogging woes, an absent drainage plan

Former deputy chief minister Manish Sisodia, who was monitoring the project, then appointed the PWD as the nodal agency and decided to engage consultants for preparing a “comprehensive drainage master plan” for each of the three drainage basins — Najafgarh, Trans-Yamuna and Barapullah.

Consultants were supposed to be appointed by March 2022. The PWD floated a tender for the Najafgarh basin in 2022, but it did not attract many bidders.

Apart from the master plan being in limbo, senior PWD officials pointed to another problem — Delhi’s drains, especially stormwater ones, are very old and are not designed to handle 125 mm of rainfall, which the city received in the last 24 hours.

“Pipelines are very old due to which water overflows… Storm-water drains have also been clogged by drainage over the years, as the population and unauthorised construction increased,” said officials.

On 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.”

Officials said consultants will also survey existing pipelines, drains and other possible stormwater disposal systems at all probable waterlogging locations to provide an effective solution.

Tenders for the other two drains were floated a couple months ago. Officials said despite the appointment of consultants, the national capital can expect waterlogging for another two-three years.

“Consultants will take at least a year to study and prepare a detailed project report. After this, work will start, which will take at least 2-3 years… provided there are no delays,” said an official.

The length of Delhi’s natural drain network is 426.55km while that of engineered stormwater drains is 3314.54 km.