So, Maharashtra is now considering an alternative site at Madh Island, on land reclaimed from the sea. Dutch consultancy firm Royal Haskoning DHV estimates that this offshore airport will cost only Rs 3,000 crore if it is built to a height of 1.5 metres, bunded and equipped with giant pumps to combat flooding during storms. Alternatively, the entire airport can be raised to a safe 7–8 metres, for Rs 6,000 crore.
It will take three years to get all clearances, but this is more than justified by the reduced cost, by avoiding displacement of 17 villages at the Navi Mumbai site, and by having guaranteed space for expansion (through further reclamation from the sea) when needed.
As living standards rise towards western levels, India will need dozens of major new airports. These will face the hurdles of land scarcity, rising population, sky‐high land prices, and opposition to land acquisition. One way out in coastal locations is to build offshore airports. This should become standard practice in India, as is already the case in other Asian countries like Japan.
Mumbai built its first airport at Juhu, another at Santacruz , a third at Sahar, and now needs a fourth. Building multiple airports, further and further from the city centre, is folly. It means huge waste and duplication in airport facilities and supporting infrastructure like connecting roads, rail lines and power lines. Huge scale economies can be reaped by building one really large airport that can be expanded, runway after runway, over decades as required . Istanbul’s new airport can be expanded to six runways . That is the way to go.
A major advantage of an offshore airport is that additional land can be reclaimed from the sea for additional runways . This is not possible in onshore sites, leading to the folly of multiple, sub‐scale airports.
Land acquisition, and opposition from environmentalists and local residents fearing noise pollution and traffic congestion , has dogged airport expansion across the globe. The answer, in coastal cities, has been to build offshore airports reclaimed from the sea. India should do the same.
Hong Kong’s new Chek Lap Kok airport, built on 3,000 acres of mostly reclaimed land, has been admired globally. Even the city’s old Kai Tak airport had a runway extending into the sea, since no spare land was available onshore.
South Korea ran out of expandable land at Seoul’s Gimpo airport. Land acquisition for a new onshore airport was difficult. So, it built a new giant airport at Incheon on reclaimed land.
Japan has built several offshore airports in recent decades. Earlier, it built a huge airport at Narita to take care of Tokyo’s needs, but expanding Narita became impossible because of agitations by farmers and environmentalists. So, Japan decided to expand an old airport at Kansai on reclaimed land. The new Kansai airport proved capable of withstanding the worst‐ever typhoon of 1998 and the Kobe earthquake of 1995. Other offshore airports in Japan include New Kitakyusha, Kobe and Chubu.
Kansai experienced a major problem. The reclaimed land subsided much more than expected, entailing additional filling and upgradation. But the airport remains safe, and a new runway is planned.
Kansai’s experience helped prevent similar mishaps at offshore airport elsewhere. Ideally, airports should be built on soils and rocks that will subside only a little. Otherwise expensive strengthening is required. Madh Island will have to be checked for this.
Environmentalist who opposed the Navi Mumbai site will oppose the Madh Island site too. There are indeed issues like subsidence, flood‐proofing and typhoon proofing. These have been tackled successfully elsewhere, and can be tackled in India too.
There’s a special reason to switch from Navi Mumbai to Madh Island. Land acquisition in India has become a racket. Politicians and sleazy speculators are early buyers in proposed sites, and they get the bulk of compensation, not oldtime villagers. It is outrageous that speculators at Navi Mumbai should be rewarded with compensation of Rs 25 crore per acre. Abandoning this site will cause local land prices to collapse , penalizing speculators for a change.
For too long, Indian policies have encouraged and enriched land speculators, including sleazy politicians. Offshore airports present a rare opportunity to reverse that trend, not just in Mumbai but in all coastal locations.