But its real success will depend on how it balances infrastructure development with environmental sustainability, experts say. 

The project, which will be undertaken on reclaimed land in Palghar district, is expected to significantly decongest Mumbai’s existing airports by handling around 90 million passengers annually. Maharashtra Chief Minister Devendra Fadnavis has approved the pre-feasibility report. A detailed project report (DPR) is in the preparatory stage.

But with the project undertaken off the coast and sea levels rising due to global warming, experts have urged caution.

“The infrastructure of this scale must be developed with environmental sustainability at its core. Offshore airports require detailed geotechnical studies, climate-resilient engineering, and continuous monitoring to address risks such as land settlement, sea-level rise, and extreme weather events,” Vandana Singh, Chairperson, Aviation Cargo, Federation of Aviation Industry in India (FAII), told The Secretariat. “Equally important is protecting coastal ecosystems through comprehensive environmental impact assessments, responsible dredging practices, conservation of mangroves, and preservation of marine biodiversity,” Singh says. 

Use Of Reclaimed Land

Reclaimed land near the sea is territory artificially created from oceans or coastal bodies of water. Densely populated regions, including Singapore and Hong Kong, have used reclaimed land to build new commercial districts, airports, and housing.

The infrastructure of this scale must be developed with environmental sustainability at its core

— Vandana Singh, Chairperson, Aviation Cargo, FAII

Kansai International Airport (KIX) in Osaka Bay, Japan, is the first entirely offshore airport built on a completely man-made artificial island. It was opened in September 1994; the airport was constructed 5 kilometres (3.1 miles) off the Senshu coast. 

It is a highly successful aviation hub, serving over 30 million passengers annually across 91 cities. 

But the engineering marvel comes at a cost: in simple words, it is sinking - faced with subsidence issues. The KIX is also built on an artificial island off the Osaka coast. According to reports, the island on which the airport was built sank 12.5 feet since the opening of the airport, while the island used for infrastructure expansion has sunk 57 feet. 

Transformative For Aviation Sector

"The proposed offshore airport in Maharashtra has the potential to transform India's aviation and logistics ecosystem by easing congestion, strengthening multimodal connectivity, and supporting future passenger and cargo growth. The planned airport is expected to handle around 90 million passengers annually, making it a significant addition to the country's aviation infrastructure,” Singh says.

Sea-Air-Land Logistics Hub

The offshore airport project is interlinked with the ₹76,220 crore Vadhavan Port project. 

“The strategic location of the proposed offshore airport paves the way for a sea-air-land logistics hub, as it is coming up in proximity to the Vadhavan Deep-Draft Port. This close proximity improves the immigration and customs process, besides the sample survey. Most often, what happens is that the movement of goods and people slows down when a port and an airport are far apart, besides causing logistical hurdles and delays in paperwork for cargo exporters,” a ports official told The Secretariat.

“At a time when even developed nations are tackling extreme heatwaves, as seen in Europe, any massive project that is undertaken has to factor in the sustainability aspect. Big-ticket projects undertaken in coastal areas have led to severe, irreversible environmental degradation in the past. So, such projects have to be carried out keeping in mind the economic and environmental factors,” Prabhakaran Veeraarasu, environmentalist and member of Poovulagin Nanbargal, told The Secretariat. 

The offshore airport project is still in the nascent stages, and it is due for environmental clearance. 

Such projects have to be carried out keeping in mind the economic and environmental factors

— Prabhakaran Veeraarasu, environmentalist and member of Poovulagin Nanbargal

According to Awkaash Kumar, CEO & Founder, Sustainable Approach for Green Environment (SAGE), and former Environmental Consultant, The World Bank, such projects require the following studies and measures: a comprehensive marine baseline and biodiversity studies, hydrodynamic and sediment transport modelling, a robust climate resilience strategy, maximising the feasibility of green airport technologies, and a cumulative impact analysis. 

Work Likely To Commence By 2030

Following approvals, the construction work is expected to commence by 2030. 

The project aims to create a world-class multimodal logistics hub connected to ports, highways, railways and freight corridors. It will significantly reduce congestion in other airports, support Navi Mumbai Airport in the long term, boost export and import logistics, and enable faster air cargo movement. 

“The project is primarily being driven by the Maharashtra government, with support from the Central government. It is not yet a private airport project like the Adani Group-developed Navi Mumbai International Airport. It is being planned alongside the Vadhavan Port to create a major integrated sea-air cargo hub, with direct links to expressways, the Mumbai–Ahmedabad High-Speed Rail corridor, and the Delhi–Mumbai Industrial Corridor,” another official told The Secretariat.

According to the official, it will take at least 15 years for the project to be completed. “From an aviation perspective, this is a highly strategic proposal rather than simply another airport,” he said.

Both the offshore airport and the Vadhavan Port are connected to the same major transport lines. Cargo and passengers moving through the airport will connect directly to the Western Dedicated Freight Corridor (a railway for heavy goods) and the Delhi-Mumbai Industrial Corridor, enhancing regional connectivity and logistics and facilitating smooth sea-to-air cargo movement. 

Rising Sea Levels

However, environmentalists have highlighted that future climate scenarios must be taken into utmost consideration, as the west coast generally shows an increasing sea level trend. "Sea reclamation of this scale will also worsen coastal erosion and saltwater intrusion, hazards that climate change is already accelerating," Veeraarasu highlighted. 

Both Mumbai and Kochi have recorded increasing sea levels over the past three decades. As per a study undertaken by CStep, Mumbai is projected to experience the highest sea level rise under future climate scenarios. West coast cities, including Mumbai, Panaji, Udupi, Mangaluru, Kozhikode and Kochi, will see around 75 cm of sea-level rise by 2100 under the medium-emission pathway. 

"The environmental aspect is a major challenge while constructing an offshore airport, and it is most effectively the coastal and marine ecosystem. It involves permanent shifting of marine habitats. On one side, coastal and intertidal habitats, vegetation, and other coastal fauna act as a natural buffer against coastal erosion and storm surge, while on the other side, marine ecology like benthic organisms, fish, shellfish, crab, and other organism who supports to sustain healthy and strong biodiversity. Establishing the offshore airport will not only damage the marine ecology, but it will also impact the coastal ecology," Kumar highlights. 

The environmental aspect is a major challenge while constructing an offshore airport

— Awkaash Kumar, CEO & Founder, SAGE

“The success of this project will ultimately depend on balancing economic development with ecological responsibility. If planned and executed using global best practices, the offshore airport can become a benchmark for sustainable infrastructure, demonstrating that India's growth ambitions and environmental commitments can progress together,” Singh adds.