Sustainable urban drainage systems

This differs from conventional drainage systems where rainwater runs quickly off hard surfaces, straight into drains and then into rivers, often carrying pollution with it. SuDS involve a range of techniques such as green roofs, rainwater harvesting, permeable paving and landscape features such as ponds and raingardens.

Benefits of SuDS

SuDS provide a range of benefits over conventional drainage systems:

• reduced flood risk – SuDS slow down the flow of rainwater from a site by filtering and storing it. This helps to alleviate pressure on our overstretched drainage system and can reduce the risk of flooding, especially after heavy rainfall. Pressures such as Climate Change and urban development are increasing the stress on our drainage system, and it is particularly important that we store or re-use surface water at source.
• improved water quality – SuDS features such as permeable paving can filter rainwater free from oil and pollutants on site, before it is returned to a watercourse via surface water drains. This ensures water entering watercourses does not harm wildlife.
• benefits for people and wildlife – SuDS create opportunities for rainwater recycling, creating attractive water features for wildlife and for people and reduce the need for expensive conventional drainage systems.

SuDS techniques

SuDS techniques which can be used in Luton include:

• living roofs – planted ‘green’ roofs store and clean water as well as provide habitats for wildlife.
• rainwater harvesting - rainwater can be collected from roofs for re-use in greywater appliances or for a water butt for watering plants in the garden!
• permeable paving - rainwater filters through permeable paving where it is stored before soaking into the ground or entering drains
• soft landscaping – landscape features, such as rain gardens, ponds and wetlands, can be designed to collect, filter and store rainwater runoff

Please refer to the Luton Design and Evaluation Guide for specific information on what SuDS techniques we look for in Luton.

We advise developers to complete the Surface Water Drainage Pro-forma for new developments and submit it to the Planning Authority. This form is supported by Defra/EA guidance on Rainfall Runoff Management and uses the storage calculator on www.uksuds.com. The pro-forma should be completed alongside other supporting SuDS guidance.

Inclusion in development

We support SuDS techniques being used on all new developments. It is also possible to retro-fit SuDS into existing buildings.

Further information

The following sites provide useful additional information about design and policy:

Susdrain - the online community for sustainable drainage

Environment Agency sustainable construction information

Thames Water SuDS information

Interim Code of Practice for Sustainable Drainage Systems

Technical Guidance to the National Planning Policy Framework