You Can Slow The Flow: At School

How schools & colleges can help & learn

Due to human Development

replacing plants and soils with hard surfaces such as roofs, roads, patios and car parking, rainfall runs off much more quickly, causing surface water and combined sewer flooding, and higher river levels.

You Can Slow The Flow At School - Development

Using SuDS to Slow The Flow

in our urban areas, as well as upstream, we can mimic natural water management. Many small changes can have a big combined effect on reducing flood water quantity and quality.

SuDS elements embedded in school life are also great educational opportunities.

You Can Slow The Flow At School - SuDS

Quick Wins

The charity Learning Through Landscapes provides resources to help you make the most of school grounds. SuDS principles provide multiple educational and wellbeing benefits.

Be a Water Hoarder!

Help to prevent combined sewer overflows by altering your actions during flood events to discharge less water into drains (as you might in drought – e.g. low-flush loos, use rainwater butts)

Yorkshire Water have information for schools, as well as water saving tips.

When can we Slow The Flow?

We hope you are able to be proactive and start right away!

However, you may not have resources to do anything right now. If so, next time you repair or refurbish property, please consider SuDS.

Free trees for schools!

The Woodland Trust give away trees to schools. You can apply each March and November for 30, 105, or 420 saplings.

Whether you have space to plant in your own grounds or not, you can also get in touch with Treesponsibility, who work with schools in Calderdale to provide tree-planting days and education, tailored to children of all ages.

SuDS Elements

(Sustainable Drainage Systems)

Rain Garden Planters

divert water from drainpipes, to slow / reduce the flow into sewers. So long as there is a plan for any overflow, they can be built over existing surfaces. Excess water can continue into the existing system, as before.

Rain garden planters are easily accessible features, that can be used to enhance  environmental studies for pupils.



Rain Garden Planter
Elzenweg, Beek, Nijmegen, Gelderland, Nederland


Ground-level Rain Gardens

(detention basins) are shallow planting areas that are deliberately located where they collect run-off and store it temporarily – they become boggy in downpours. As they are dry most of the time, many everyday plants can cope with the conditions. A layer of gravel below the topsoil helps increase storage capacity.

Rain gardens can collect run-off from paved areas, or take water from the roof via diverted drainpipes. Water conveyance can be creatively used as an attractive play /learning feature.





can just be a dip in a lawn, or can be planted with meadow seed and plug plants, to provide a biodiversity corner that needs mowing less often, provides a stimulating place to play, and helps to demonstrate various syllabus areas.


Swales can direct water to a pond, or just allow it to soak away. Ponds can be a useful educational resource for several subjects.

Swale at Olympic Park


Green Roofs

and blue roofs (without vegetation) can be put on all flat / gently sloping roofs, from classrooms to bicycle / scooter / outdoor classroom shelters. Professional advice should be sought, to ensure loading and waterproofing are appropriately handled.

Sedum roofs and blue roofs can be lighter than bio-diverse planting schemes, which need deeper soil. All can be designed to need very little maintenance, and green roofs look attractive!

Green walls can also be similarly retrofitted, and may be more visible to pupils, providing additional learning opportunities.

Green Roof Outdoor Classroom
Green Roof



have multiple benefits for biodiversity, air quality, aesthetics, health and study.

Trees stop up to 12% of rainfall hitting the ground, even in winter.

They also improve the rate at which water infiltrates the soil, and reduce erosion (preventing sediment from blocking water courses). Tree pits can be designed to store and slowly release water.


Living Willow Den
Permeable gravel tree pit
Trees in swale, Upton


Permeable Surfaces

can replace car parks, play areas and paths with materials that don’t shed water, such as:

  • gravel
  • reinforced grass
  • porous surfaces
  • permeable paving
  • slabs/setts on gravel and without mortar

If constructed correctly, extra water can be stored underneath, whilst allowing the surface to continue to be used.

Gravel car park and swale
Permeable car park

Larger Schools

Interventions for larger school premises are more likely to need professional advice – particularly if you intend to:

  • increase the volume at any outfall point
  • work very close to a permanent river or stream (within about 10m)
  • make changes to a listed building or in a conservation area
  • create a green roof
  • re-use grey water in buildings
  • create reed beds to treat waste water
  • do anything that could affect your neighbours

NB. Remember we have a varied geology, i.e. water runs through sand, but if you are working with clay, it may puddle rather than soak in.


Download the printable 2-page PDF below:


You Can Slow The Flow has been kindly sponsored by our friends in the Calderdale Flood Partnership, through the SOURCE partnership, and created by 2B Landscape Consultancy Ltd