Design of Sustainable Drainage Systems (SUDS)
Reducing and slowing down the run-off
SUDS techniques aim to mimic the natural drainage of a catchment by reducing and slowing down the surface water run-off from a site. Many of the features used treat the problem of surface water run-off at source, so reducing costs of pipework, manholes and other ancillaries.
Full range of SUDS techniques
We have the capability to design the full range of SUDS measures for new developments including:
• Source control.
Using such components as soakaways, rainwater harvesting systems, green roofs,
filter strips, pervious pavements, filter drains and infiltration trenches.
• Site control. These measures include ponds, detention basins, wetlands and infiltration basins.
• Conveyance Systems including pipe networks, swales and open channels.
These would be incorporated as appropriate to form a 'SUDS management train' to incrementally reduce the surface water peak runoff flow, volume and pollution. SUDS are best incorporated into a site's design right from the early stages so that the best use is made of the available space to ensure that an overall cost effective site layout is arrived at.
Implemented through the planning system in England
The government has decided that the application of SUDS to development sites will be implemented through the planning system in England and the 'Non-statutory technical standards for sustainable drainage systems' were published in March 2015. These standards came into force in April 2015 and apply to sites of 10 or more houses and similar sized commercial or mixed developments.
The English technical standards are very brief so it is likely that the CIRIA document C753, 'The SUDS Manual', 2015 will continue to be an important source of information.
Implementation of Schedule 3 of F&WMA in Wales
The Welsh government implemented schedule 3 of the Flood and Water Management Act 2010 on 7 January 2019. This set up the SUDS Approving Bodies (SAB's) and requires the use of SUDS on new development sites of more than one property or sites with a paved/roof area greater than 100m2. The SUDS Approving Bodies are in fact the unitary authority (County, County Borough or City Councils) and they approve, adopt and maintain SUDS features into the future.
The Welsh Government published the 'Recommended non-statutory standards for sustainable drainage (SUDS) in Wales' for use on an 'advisory basis' in January 2016 and these were replaced in 2018 with the final statutory standards themselves.
Morton-Roberts has the capability to design the full range of SUDS measures, please contact us for more details.
Photograph: Detention basin, Hamilton North, Leicester.