London ( CNN ) -- Many visitors to London will be used to flying over the Thames before they land . Within less than 10 years , they could be touching down at an island airport in the middle of the river itself . A futuristic-looking , six-runway airport on an artificial island has been proposed at a location off the Isle of Sheppey , around 80 kilometers from the center of the city . The plan from a consortium formed by the mayor of London , Boris Johnson , has been projected to cost Â£47 billion ( $ 76 billion ) and to take seven years . With Heathrow running at 99 % capacity , the capital needs more runways , the consortium , Testrad , says . The mid-river location is intended to avoid adding to the aviation noise pollution already bedeviling London -- the source of long-running campaigns from residents beneath that approach into Heathrow that passengers so enjoy . New beginnings at the world 's busiest airport . Trees growing in terminal . A visualization of the proposed London Britannia Airport shows an oval-shaped stucture bisected by runways , sitting in the Thames where the river widens to form an estuary . Interlinked , translucent hemispherical pods cover the concourse and other passenger areas -- the light they admit allowing trees and other vegetation to grow within . Heathrow Airport , currently the busiest in Europe by passenger traffic and the third busiest in the world , would close if Britannia Airport went ahead , Gensler , its designers , said . Passenger numbers to all London 's airports are expected to more than double by 2031 , to 300 million from 127 million a year in 2010 , according to the Greater London Authority . More : Viagra among best cures for jet lag ?
Airport ##s sit on artificial artificial island . Estimated $ 1 billion project is expected to take seven years . Transparent hubs covered with trees would form passenger terminals . Heathrow ` ` to close '' if not completed .