South East Rivers Trust (& the Wandle Trust)

SuDS can reduce flood risk 

SuDS replace hard, impermeable surfaces with features that help restore the natural water cycle.  Runoff from roads and roofs are diverted into areas where it can be absorbed or temporarily stored so the drains don’t become overwhelmed.  In rain gardens, for example, rainwater from the roof is diverted into an area of planting.  Most of the water will soak into the ground to water the plants.  Excess rainwater only enters the drain once the ground is saturated.  Contaminants are filtered out as the water flows through the rain garden

This rain garden makes use of the rain from the roof.

SuDS can protect rivers

By diverting runoff into SuDS features the quality of water flowing into the river can be improved.  The surface water drains in the Wandle Valley all feed directly into the River Wandle. As rainwater flows towards the drains and into the river, it becomes contaminated with oil, litter and other harmful chemicals and debris.  By directing this runoff into SuDS, contaminants can filtered out.


Here are examples of other SuDS features that can be installed within school grounds or at home to slow the flow of rain to the drain and reduce contaminants entering the river.


For more information about how SuDS work check out the SuDS in Sutton’s Schools World Water Day blog.