Design

Cleaning Up Urban Waterways With Manmade Islands

The brains behind Scotland's Biomatrix Water use flotillas of plants to filter polluted water and soften concrete riverbanks.
dominique landau/Shutterstock

About 10 miles west of central London, Hanwell is one of the towns that sits along the River Brent, a tributary of the Thames. As is true with many urban rivers, the Brent is bordered by concrete walls as it flows through towns and has been heavily polluted by industrial effluent and sewage.

Recently, a local environmental nonprofit called the Canal and River Trust wanted to restore the natural riverbank, but was thwarted from taking out the concrete retaining walls because of concerns over flooding. But the group found a clever alternative—a system of floating wetlands that would bring back the natural edge.