Recent motorway interchange redevelopment projects within the dense urban fabric of the Quebec City metropolitan area (Canada) have provided an opportunity to introduce various innovations, particularly in relation to traditional surface water retention basins. Retention structures have become overgrown with invasive exotic plants, leading to the adoption of specific design criteria to limit the invasion of road land. With wetlands becoming scarcer and urban landscapes increasingly homogenised, the Quebec Ministry of Transport has also agreed to take steps to promote such components in its projects.