An area of foreshore and sea-bed in waters north of the airport will be reclaimed for the HK$141.5bn (£12.3bn) project.
The works include: formation of 650ha of land by ground improvement and sea-bed filling; seawall construction; approach lights and beacons; and diversion of one set of existing 11kV, 6km-long submarine cables.
The Airport Authority will start work at the earliest opportunity and the entire three-runway system project is expected to take about eight years to complete.
Mott MacDonald is designing the third runway, infrastructure and concourse at the airport (link opens in new tab).
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