Area characterisation

The schools were selected for this project because their sites drain into Critical Drainage Area 33 (CDA 33) within the London Borough of Sutton. The area was identified by the council as a high risk area for surface water flooding. It is part of the Wandle Catchment and the sewer network mostly consists of separate drainage systems for wastewater and surface water, with the surface water draining directly into the river. 

Sustainable drainage systems (SuDS) features for this project were built on 3 school sites but the engagement activities were delivered across 7 schools altogether to facilitate a wider SuDS project being delivered by the council. The schools included 1 infant school, 2 junior schools, 2 primary schools, a special school and a secondary school.

Objective

The aim was to deliver sustainable drainage systems (SuDS) measures on school sites in order to reduce local flood risk, provide benefits for participating schools and educate the pupils and wider community about surface water flooding .  

Actions

  • Schools were recruited to the project
  • A range of staff engagment activities were carried out
  • A number of different education and engagement activities were trialled with pupils
  • A range of SuDS planters were designed in reponse to staff and pupil input
  • 10 SuDS planters installed (by project end)
  • A monitoring system for evaluating the success of different planter designs was trialled

Potential impacts/benefits

  • SuDS planters installed to alleviate local flood risk.  This project will attenuate runoff from more than 500m2 of roof area and provide approximately 10m3 of storage
  • A range of SuDS education sessions delivered to  staff and pupils. This project engaged approximately 3000 pupils and staff members
  • Greenery added to very grey playground spaces -  more than 22m2 of planting will be added
  • Other amenity benefits such as seating and enhanced school entrances
  • New educational facilities for activities such as gardening, mini-beast hunts and sensory play
  • Demonstration SuDS to raise awareness of surface water flooding among pupils and the wider community
  • Publicising the 'SuDS not floods' message - over 2000 people were reached through public engagement activities

NBS benefits

  • Developing climate change adaptation; improving risk management and resilience
  • Flood peak reduction
  • Increase infiltration / Water storage
  • Increasing infiltration
  • Reduce flood risk
  • Reduce load to sewer system
  • Reduce run-off
  • Increase quality and quantity of green and blue infrastructures
  • Changing image of the urban environment
  • Increase awareness of NBS solution & their effectiveness and co benefits
  • Increase communities’ sense of ownership
  • Increase social interaction
  • Increase stakeholder awareness & knowledge about NBS
  • Increase well-being
  • Increase willingness to invest in NBS
  • Social learning about location & importance of NBS

Transferability of the result

Delivering 10 planters and engaging 7 schools has given us a chance to trial and refine a methodology for delivering SuDS in schools.  We now have an establish SuDS offer that includes a range of engagement activities and planters to suit different budgets and school needs. 

In April 2021, reports will be published to provide guidance for other organisations on the methods used and the lessons learned.  These will cover topics such as education and engagement, design, installation and monitoring.  

Lessons learned

  • Plan carefully to integrate school engagement with design and delivery, early input is useful for design but too early and the connection to installed features will be lost
  • A well-designed feature on paper sometimes encounters unforeseen problems on site, include a contingency in the budget 

Financing

Project funders include:

  • The Environment Agency
  • Thames Restoration Fund
  • London Borough of Sutton

Targetting schools for SuDS projects can have two clear advantages.  Firstly, there are large expanses of impermeable surfaces on school sites - huge roof areas and large tarmac spaces – from which to capture run off.  In addition to this, schools are the hub of the community and, as such, provide a unique opportunity to garner widespread support for SuDS both within schools and beyond.  The only drawback is that schools are busy sites and it can be difficult to integrate SuDS with the needs of the school.

In this project, an Education and Community Outreach Officer was appointed to liaise with the schools.  The remit for this post was to gather input from the schools to ensure installed features reflected their needs and to exploit the opportunities for raising SuDS awareness with staff, the student population and the wider community.  A wide range of activities were undertaken.

  • Staff were given the chance to input their ideas through staff surveys, staff meetings and interactive mood boards 
  • A range of sessions were delivered with pupils including assemblies, lessons, design input sessions, planting days and special projects (such as a SuDS animation project) to help them engage with their SuDS and give them a chance to contribute directly to them
  • The wider community was engaged at events such as school fairs and local festivals to raise awareness and garner widespread support for the project

Involving stakeholders in this way ensures the school will feel a sense of ownership and pride towards their SuDS so that they will be valued for years to come.  

Based on the input we received, ten SuDS planters were designed, six have been installed and the rest are due for completion in April 2021.  Designing this many planters has provided the opportunity to trial different designs to reflect the needs and interests of individual schools.  These  designs include interactive mini-beast planters, bees and butterfly planters, planters to create a sensory garden area and planters with benches in a school picnic area.  Designs also include creative solutions to connect the planters to existing drainage.

Different storage methods were also trialled to maximise the potential for attenuating runoff during heavy rainfall events.  Some planters include a gravel base layer for storage and others have a geocellular storage layer. Monitoring equipment has been added to one of each type of planter to provide data on the effectiveness of the different designs.

Working with several schools and delivering on sites with different opportunities and barriers has been invaluable in developing a methodology that can be applied to a range of sites in the future. 

Contacts

Charlene Duncan charlene@southeastriverstrust.org

The South East Rivers Trust info@southeastriverstrust.org

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