CONSULTANTS HAVE accused the government of grossly underestimating the cost of building a new London airport in north Kent.
A report produced for Kent County Council by Mott MacDonald warns that the government's proposed 26ha four runway airport at Cliffe Marshes will also take longer to build than expected.
Costed at £13.6bn, Cliffe emerged as one of the options for expanding air capacity in the government's South East Regional Airport Study (SERAS).
This was carried out by consultants Halcrow, Scott Wilson and Arup and published in July (NCE 25 July/1 August).
But Mott MacDonald's study, seen this week by NCE, predicts the project will cost £3bn more than SERAS anticipates.
It says this is because SERAS excluded many of the surface access costs such as a £700M Thames crossing, £400M of road tunnels and £200M of other road and rail projects which would be needed to serve Cliffe.
An extra £500M should also be added to the cost of earthworks 'given the lack of information on sub strata, ' it says.
The assumption in the SERAS report that Cliffe could be opened by 2011 is also rubbished by Motts.
It claims 2018 or even 2025 are more realistic dates. It would take 10 years to create compensation habitats for displaced bird species before an eight year construction process could start, the report adds.
The report for KCC, which is opposed to the Cliffe option, will feed into the government's aviation White Paper, expected in the new year. This will confirm locations for major new runways in the South East.
Mott MacDonald argues that rather than build a huge new airport the government should wait and see how the market develops and build runways one at a time.
INFOPLUS www. airconsult. gov. uk