The Mumbai International Airport Limited (MIAL) had proposed diverting the river.
Consultants from the Indian Institute of Technology, Bombay (IIT-B) said that widening the culvert that runs under the main runway is the only option.

The report says diverting the Mithi would not be possible because the area is hilly.

“The culvert is 27 m wide and 4.1 m high. The width should be increased by 20 m,“ said the report, submitted by IIT pro- fessor Kapil Gupta to the Brihanmumbai Municipal Corporation.

The BMC has been urging MIAL to widen the culvert for the last two years but because of several security concerns, the airport authority is yet to agree.

Professor Kapil Gupta, from the Indian Institute of Technology­Bombay was appointed by the Brihanmumbai Municipal Corporation (BMC) to study the plan.

Gupta has instead recommended the widening of the culvert under the runway, a suggestion the BMC had also given.

“The culvert is 27 metres wide and 4.1 metres high. The width should be increased by 20 metres to sustain rainfall of 100 mm in an hour,“ says the report submitted to the BMC on March 15.

A copy of the report is with Hindustan Times.

The report says diverting the Mithi along Andheri­Kurla road is not possible because the area is hilly.

Civic sources said diversion will require resettling more than 40,000 slum settlements.
“The report has said that widening of the culvert is the only solution. MIAL will have to undertake the widening,“ said Additional Municipal Commissioner, R.A. Rajeev.

The BMC has sent the report to the government.

An MIAL spokesperson said, “We have submitted a report to the state government, MMRDA and BMC addressing the issues that will come up while diverting the flow of the river. A meeting will be held with the chief minister in a month to decide which plan is to be executed.“

If the culvert under the run- way is not widened and the Mithi overflows in the monsoon, chances of water logging on the runway are high.

The Chitale committee report of 2007 and the Central Water and Power Research Survey had said the stretch of the river near Krantinagar, Kurla, should be widened to 100 metres downstream and 40 metres upstream and the culvert under the main runway should be widened to 60 metres.

The BMC widened the river last year, but until the culvert is widened water logging will continue.

“The stretch of the river under the runway is only 27 metres wide and creates a bottleneck leading to flooding. When the Mithi swells, water enters the runway affecting air traffic,“ a civic official said requesting anonymity.

The BMC has been pursuing the matter with MIAL for two years. “The MIAL had securi- ty concerns and was worried the runway may collapse if widening is undertaken,“ the civic official said.