The sprawling marshes and fishponds in Hong Kong’s northwest, bordering the Chinese tech hub of Shenzhen, provide foraging and roosting grounds for hundreds of bird species, including the threatened Black-Faced Spoonbill and Saunders’s Gull. At more than four times the size of New York City’s Central Park, the reserve is also a carbon reservoir that is crucial in the fight against climate change and could help alleviate flooding during typhoon season.

Amid determination by Hong Kong’s new administration to resolve its chronic housing problem, developers are scrambling to find land to build new apartments. But with much of Hong Kong Island and the Kowloon peninsula already well developed, they’re turning their attention to relatively untapped sites in the city’s hinterland, putting protected natural sites at risk.

The city’s largest property developers have ambitious proposals to build apartment blocks on the wetland’s fringe — a buffer zone of some 1,000 hectares (2,500 acres) along the inner boundary of the reserve that was designated by the government more than two decades ago to prevent any development that would have a negative impact on the area. Any building work earmarked within the zone must come with an environmental impact assessment. Major property developers are now testing the limits of how far they can push into that area.

The emboldened property groups and the government’s seeming willingness to sideline environmental concerns is worrying conservation groups, which have raised their opposition to proposed apartment blocks with the Hong Kong’s planning board.

“I have a lot of reservations on whether their plans will have no impacts on ecology like they say in the applications,” said Roy Ng, campaign manager at the Conservancy Association.

At present, plots within the buffer zone are supposed to produce low-density developments. However, eight of the proposals were updated in the past year to request much higher density, according to Conservancy Association and documents from the Town Planning Board, resulting in over 25,000 units.

Though the newly proposed projects would not be the first to be built in the buffer zone in recent years, they would be far higher in both height and density. The potential windfall is huge — a completed apartment of 500 square feet (46 square meters) near the wetland currently sells for about HK$8 million (US$1 million).

Three of Hong Kong’s biggest developers are behind seven of the eight proposals. Henderson Land Development Co. was previously granted permission to build 71 low-rise houses in a project but is now seeking to build 10 towers with heights ranging from 16 to 23 floors. Sun Hung Kai Properties Ltd. plans to build towers as high as 29 stories.

The proposed development poses grave dangers to the wetlands, say conservation groups. Construction noise and other human activities could impact the foraging behavior of birds, while tall buildings threaten their flight paths.

“The birds need to fly back and forth multiple times a day to sustain the young birds,” said Suet Mei Wong, conservation officer at the Hong Kong Bird Watching Society, one of the groups opposed to the development applications in the buffer zone. “Tall buildings in the buffer zone may break the flight paths that are crucial for the birds’ reproduction.”

The groups also argue that developing housing near the wetlands ignores the dangers from climate change. Hong Kong is already one of the Asian cities that is most at risk from higher sea levels, while the northwest of the New Territories, where the wetlands are located, has a particularly high chance of flooding. The most exposed areas can expect disastrous storm surges once a decade by the 2050s, according to Greenpeace.

Protecting wetlands is crucial in staving off the impact of climate change, as they are estimated to hold more than one third of the world’s carbon stored in soils. Governments including China’s are increasingly acknowledging the importance of wetlands, with the country’s first legislation to preserve them coming into effect in June.

Concern groups also criticize the developers’ wetland ambitions as backtracking on their recent pledges to become more socially responsible. In recent years, these companies stepped up their efforts to take environmental, social and governance issues into account by donating land for social housing and assisting low-income families during the pandemic. They have also won green certification for new skyscrapers.

“The majority of things we see from Hong Kong developers are more for PR,” said Brian Wong, a researcher at think tank Liber Research Community. “In reality they do a lot of things that are in contradiction with the spirit of ESG,” he added, citing the growing number of micro apartments being built as an example.

The Town Planning Board has scheduled to discuss seven of the eight buffer-zone proposals in the next three months. Until now, the threshold for approval in such areas has been high, but that may change amid growing signs that the government is willing to prioritize development over environmental considerations.

The wetland buffer area exists to mitigate the negative disturbances of development on the wetlands, not to prohibit development, a spokesperson from the Development Bureau said. Applicants have to demonstrate that their proposals would not compromise the objective of protecting the nearby wetlands, he added.

A spokesperson for property group Sun Hung Kai said in a statement that much of the buffer area is now “abandoned wasteland or degraded fishponds with low ecological value” and that it supports “a balanced mix of actively-managed wetland with well-planned developments.” He added that for a previous project within the buffer zone, the developer adopted designs to facilitate natural wind flow, included a large green belt between residences and the wetland and devised a construction process that minimized impact on the wetland.

New World Development Co. declined to comment. Henderson Land did not respond to a request for comment.

Last year, a government official proposed raising the plot ratio for sites in the wetland buffer area to allow more homes to be built. More recently, the head of the city’s Environment and Ecology Bureau said that the government is considering re-zoning the conservation and buffer areas.

Outside of the wetlands, the government endorsed a controversial decision to build a third airport runway and is mulling an US$80 billion artificial island to dramatically increase home supply. Those projects are located on or near Lantau, Hong Kong’s largest island, whose waters are home to the endangered Chinese white dolphin.

In a city with a chronic housing shortage, some argue environmental protection should not stymie development.

Ryan Ip, head of land and housing research at think tank Our Hong Kong Foundation, said he supports the idea that developers can help revitalize neglected parts of the buffer zone if granted permission to build there.

“The more sources of land supply, the better,” said Ip.