What the heck are those floppy white strips in the ground at the McKenzie Interchange project?

Well, it turns out they’re a valuable tool for drainage in highway construction.

The strips, about four inches wide have a fibrous exterior wrapped around corrugated plastic, allow ground water to seep in travel to the surface.

They are rammed into the ground by a large machine up to 15 metres deep until they reach bedrock.

The wicking away of water allows the fill to compact quicker and properly before paving.

On the McKenzie Interchange project 18,000 of these will be inserted into the fill using up to 220 kilometres of the material.