An innovative project using bubbles to form a barrier to plastic waste in Amsterdam’s waterways is proving so successful the city authorities want to expand the project to five other areas.

The Bubble Barrier was launched in 2019 and since then has caught some 190,000 pieces of plastic waste a year, weighing around one tonne, according to an official report on the experiment.

“We expect the Bubble Barrier to catch 86% of floating plastic before it heads for the IJ waterway and flows into the sea,” city waterways chief Melanie van der Horst has told councillors, outlining her plans to expand the project.

The barrier consists of a 60m punctured pipe that runs along the bottom of the channel. Compressed air is pumped through, and rises as a curtain of bubbles; thanks to its diagonal positioning and the river current, the bubbles push pieces of plastic and rubbish upwards and to one side, where it can be collected.

The city is now planning to use a bubble barrier on five other places in the western IJ at a cost of €600,000, plus €50,000 a year in operating costs.

The locations are out of the way of shipping, but the impact on migrating fish still needs to be assessed, Van der Horst said.