South East Rivers Trust

Making Sutton’s schools rainwater friendly!

SuDS in Sutton’s Schools

The South East Rivers Trust and Sutton Council are working in partnership on the SuDS in Sutton’s Schools project.  Sustainable Drainage Systems (SuDS) are measures that slow the flow of rainwater rushing to the drains.  The SuDS in Sutton’s Schools (SiSS) project will be installing SuDS at the council’s Denmark Road offices and 7 schools in Carshalton.  The SuDS at these 8 sites will massively reduce flood risk in the local area.


Why install SuDS in schools?

The SuDS in Sutton’s Schools (SiSS) project will be installing SuDS in local schools:

  • To reduce flood risk
  • To ensure water entering the River Wandle is cleaner
  • To save water from going straight down the drain
  • To improve playgrounds spaces with new and interesting features
  • To increase opportunities for cross-curricular outdoor education
  • To improve the area for wildlife
  • To educate pupils and the wider community about water issues


Why are SuDS needed?

In a natural landscape, rainwater is able to be useful. It can soak into the ground so plants can use it. It pools in ponds and wetlands, creating wildlife habitats.  Some of it soaks deep into the earth where it is stored as groundwater.  A small amount of rainwater becomes surface water runoff, flowing into rivers and out to sea.  However, as more and more of the natural landscape is built over, this natural flow of water is disrupted. In built up areas, rainwater is prevented from soaking into the ground. Most rainwater becomes surface water runoff. The rainwater that lands on the Wandle Valley’s roofs, roads, pavements and parking lots rushes to the drains which empty out into the River Wandle. Not only could the river burst its banks but drains could overflow.  The drainage network was not built to cope with all this surface water runoff.


Another impact of this increased surface water is poor water quality in our rivers. As rainwater flows towards the drains and into the river, it becomes contaminated with oil, litter and other harmful chemicals and debris.  The water washing off our roofs, pavements and roads has a negative impact on the river ecosystem. Watch the video below for evidence of the problem.


How SuDS work?

Learning resources 

Case studies

What you can do