The pipes were loaded on to large reels in Kalunborg, in Denmark, before being transported to the Solent on a barge.

In the Solent, the pipe-laying barge the Pontra Maris was used to install the two-kilometre pipes up to one metre under the seabed using specialist equipment.

The pipes were slowly unravelled from the reels and filled with water so they sank to the seabed under their own weight. High pressured water was used to remove sand from the seabed and return it on top of the laid pipes.

The main sits in a ‘no anchor’ corridor, used by other services such as telephone, gas and electric, and a concrete ‘mattress’ was laid over the top to help protect the pipes from accidental damage.

Finally, divers connected the pipelines lying on the seabed with the connections on the shoreline to complete their journey.

During the construction, there were several barges manned by specialist contractors working in the Solent to ensure the operation went smoothly.

Before the new pipes could be used they were sterilised by being disinfected with chlorine to make sure they were clean enough to transfer drinking water.