The warning was made by construction industry organisation Dansk Byggeri and first reported by newspaper Politiken.

“It seems as though the project leaders have forgotten about all the building that is planned for the islands,” the group’s political director Torben Liborius told the newspaper.

The organisation estimates that at least ten new trenches, each the size of 20 football pitches, would need to be dug in order to provide the necessary raw materials.

“That is why it is already necessary at this point to develop a national plan for raw materials in order to secure the necessary building materials,” Liborius said.

Earlier this month, the government and Hvidovre Municipality announced a plan to extend the Avedøre Holme area south of Copenhagen, creating nine new islands to be promoted as a ‘Danish Silicon Valley’.

That followed another major infrastructure initiative announced last autumn, whereby 20,000 new homes will be built on low-lying land reclaimed from the sea near Refshaleøen north of the capital. That development, given the name Lynetteholmen, is scheduled for completion in 2070.

Approximately 25 million cubic meters of sand, gravel and stone will be needed to build the islands, according to Dansk Byggeri.

Those raw materials could be sourced in Denmark, but Liborius said he foresaw political disagreement over where quarries could be dug to source them.

Minister for Food and the Environment Jakob Ellemann-Jensen agreed that an overarching plan for sourcing raw materials was necessary.

“One of the reasons we are proposing the state takes over the task of providing raw materials from regions is that it will allow us to think more long-term, strategically and not to be limited by regional borders,” the minister told Politiken via email.

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