Kerala floods: The inundation of Kochi airport was a disaster waiting to happen

As heavy rain continues to lash Kerala, the government announced on Thursday that the flooded Cochin International Airport would remain closed until August 26. The international airports in Thiruvananthapuram and Kozhikode districts will accommodate the traffic from Kochi, which is Kerala’s largest airport.

The state is in the grip of what has been called its worst monsoon in almost a century. The toll from the floods leapt to 184 on Friday from around 80 the previous day, with the state government saying close to 100 people had died within 36 hours.

While the full extent of the damage to Kochi airport is not yet clear, the shutdown of the facility is unprecedented. No major airport in India has had to close for 11 days due to rain. Ernakulam district, where the airport is located, received 124% more than the normal rainfall for the week ending August 15. News reports from the district mentioned people being stranded in their homes in areas very close to the airport.

The flooding of Cochin International Airport is an event foreseen. The facility, which opened in 1999, is barely 400 metres from the Periyar river. When the airport was built, a creek, the Chengal Thodu, that served as a distributary from the river and three irrigation canals that provide water to nearby paddy fields were realigned to make space for the runway, as a coffee table book published by the Cochin International Airport Limited says. The airport’s drainage system leads into the Chengal Thodu, which in turn is connected to the Periyar.

By realigning the creek, the airport authorities ended up narrowing it, said CR Neelakandan, an environmental activist and state convener of the Aam Aadmi Party who had raised concerns about the airport in the 1990s.

“The airport area is the floodplain of the Periyar,” Neelakandan pointed out. “If you take a flood plain, there is every chance of a flood, even after you reclaim it. Chengal Thodu is the only line connecting Periyar to other rivers.”

Neelakandan said that when he had asked the authorities what would happen in the event of a flood, they had replied that Kerala’s dams would help control it, but also that floods were a thing of the past. “People like us were afraid, but that was only a fear we could not prove,” he said. “There was no evidence at that time. This kind of flood coming in from the Periyar was not envisaged by anybody.”

Now, with the opening of the gates of the two major dams on the Periyar – the Mullaperiyar, which is operated by the Tamil Nadu government though located entirely in Kerala, and the Idukki – everything downstream is inundated, including the airport itself.

2013 flood

Though diminished, the Chengal Thodu is still a significant part of the lives of those who live near it. It frequently overflows during the monsoon and the resultant waterlogging is exacerbated by a tall concrete wall built by the airport to prevent the water from entering its runway. In 2013, when the gates of the Idamalayar dam on the Periyar were opened, the Chengal Thodu had overflowed, forcing residents to shift to relief camps and the airport to shut down for two days.

Later that year, the airport widened its drainage channels, stocked up on sandbags, invested in pumps and strengthened its boundary wall. None of these measures seem to have been able to withstand the force of the water flowing down the river at present. The airport has now begun to demolish the wall – this time to let the water out.

Encroaching on the Periyar

Built 25 km outside Ernakulam city in Nedumbassery, the Kochi airport is the first public-private partnership greenfield airport in the country. (A greenfield airport is one that is built from scratch on an undeveloped site.) A part of its funding came from non-resident Indians living in the Gulf, keen on cheaper flights home. The Gulf Cooperation Council countries have been a favoured destination for migrant workers from Kerala for decades now and the airport provides direct connectivity to these. The state government initially held a 74% stake in the airport while 26% was held by private citizens. As of 2015, the government holds a 32% stake.

Environmental clearances for land acquisition projects became compulsory in India only in 1994. This clearance is granted to a project on the basis of an environmental impact assessment. In the clearance granted to Cochin International Airport on March 15, 1995, only one mention of the canal is made:

 “For diversion of Nallah [Chengal Thodu], appropriate measures such as construction of bund/diversion canal etc. to regulate the flow of water from Periyar River into the existing Nahlah must be adopted to ensure that the overall hydrology of the area does not change.”  

As land acquisition for the project faced protests, the original design of the airport was revised, according to a case study by the Indian Institute of Management, Ahmedabad. In the revised design, “the eastern boundary extended till the Periyar river”, the study stated.

Construction on or near the canal has continued apace since then. In 2017, there were reports that the airport company, as part of its push towards operating entirely on solar power, had built a six-megawatt power plant on concrete stilts over the canal. The status of this plant is not clear at present, given the extent of flooding in the area.

The airport company also suggested reviving the Chengal Thodu, to use it as a waterway to Ernakulam city via the Periyar.

Other airports, similar stories

Kochi’s airport is not the only one to flirt with ecological disaster. In 2011, the Chennai airport in neighbouring Tamil Nadu extended its second runway by building a bridge over the Adyar river. During the flooding disaster that hit the city in December 2015, the river overflowed into the airport, forcing it to shut down.

Mumbai airport, which handles the highest passenger traffic in India after the Delhi airport, is also a river encroacher. Its first runway, reported The Times of India in 2005, was built on a culvert over the Mithi river. The second runway, which forms an X-shape with the first, extends directly into the river itself, gradually narrowing it down with each extension. The report cites this as one of the reasons the Mithi did not drain out the water from the city when it was paralysed by flash floods on July 26 that year. After the floods, the airport built a second channel to allow for more drainage.

Nor has Mumbai learnt from its mistakes. A new airport slated to come up in Navi Mumbai also plans to reclaim marshy land and divert the course of the Ulwe river, setting the scene for floods when the area receives heavy rain. An airlines consultant told Mint that the project was a disaster.

Airports are affected by rain even when not built over rivers. This year, a boundary wall at the international airport in Bhubaneswar collapsed after heavy rain. The airport is near the Mahanadi river but not on it. Last year, the runway of the Ahmedabad airport sustained damage as a result of waterlogging, reports said.