MIAL considers new course for Mithi river

The airport authority has proposed that an additional channel, parallel to Mithi river, be made to avoid flooding of the airport during monsoon. It is also proposing to raise roads at Air India Colony. Manisha Singhal looks at what the project entails

The Mithi River must be realigned. That is the solution the Mumbai International Airport Limited (MIAL) has come up with to avoid the horrors of flooding at Mumbai’s airport. Right now, the proposal is under consideration at the Central Water and Power Research Station (CWPRS) in Pune, and a feasibility study is also being done by IIT-Bombay. MIAL met the IIT experts on Thursday.

“We do not want an airport that floods during the monsoons,” said the MIAL spokesperson. A well-placed source at the Mumbai Metropolitan Region Development Authority (MMRDA) said, “Initially, the MIAL had suggested to the MMRDA that the Mithi River’s course must be altered so that it does not flow into the airport.”

But the proposal was rubbished by the CWPRS, and it also did not find favour with the MIAL as it required the closure of the runways till such time as the work is completed. So, the next course suggested by the MIAL is to get a parallel channel or an alternate channel along the current course of the river, which would be able to handle the excess drain and tail waters from the Powai and Virar Lake, thereby avoiding the flooding of the airport.

“The MIAL has proposed a realignment of the Mithi River. But it is too early for us to comment on it. We will just be giving a hydraulic feasibility about the proposal. There are lots of other socio-economic and legal issues involved,” said VM Bhendre, director of CWPRS.

Meanwhile the MIAL spokesperson expressed the authority’s concerns over the fact that the Mithi runs under the runway. He said, “Ideally, you cannot have a river running under the runway. We did not have the option of widening the river as that would require closing down the runway. The proposal is to make an additional channel which would circumvent the runway.  This way the excess water will be channelled through it, and this will deal with the problem of flooding without operations being disrupted.”

Also, if the proposal to circumvent the runway on the eastern side is passed, land that is currently occupied by slum dwellers will have to be cleared. Getting that land would again be an issue for the MIAL, as it is already entangled in resettlement and rehabilitation issues.

If the antecedents of the airport are looked into, the first and the main runway (09-27) of the airport was built across the Mithi. When the second runway — a shorter which cuts across the main runway from north-west to south-east – was built in the 1970s, it had raised a debate. The runway was shorter and could not be used for heavier aircraft. But as air traffic grew, the respective airport authorities kept on pushing the runway towards the edge of the river. With current cross-runway operations and about 640 air traffic movements daily, building more infrastructure has eaten into the Mithi River, reducing its capacity.

Even the Mumbai Flood Report, prepared by the Bombay Environment Action Group (BEAG) after the July 26, 2005 deluge, had mentioned that the airport had seriously damaging the Mithi River. “The proposal to concretize the entire airport surface means that the earth will have to absorb more water during the rains, and the capacity of the storm water drains and also the river would have to be augmented,” said Debi Goenka of BEAG.

Though the second phase of the Mithi River Development Project was cleared in 2006 and talked about the deepening and widening of the river, that option was not feasible for the airport. “Why should there be obstacles and rivers flowing beneath the runways at an international airport,” questioned the MIAL spokesperson.

The problem with the implementation of the suggestions for widening and deepening of the river, in the case of the airport, is that for any work to take place, the operations of the runway will have to stop. It is not even clear how long would the exercise would have taken, therefore the proposal was reworked by the MIAL. “It is too early to talk about the proposal. We are just considering the options and feasibility. There is neither a time frame nor a deadline,” said the MIAL spokesperson.

The MIAL is also mulling over the idea of demolishing the entire Air India Colony, which gets flooded very monsoon, and raise road levels to avoid flooding said a source.