Sustainable Drainage System (SuDS)

From 07 January 2019, all new and significant developments will have to implement some kind of sustainable drainage system (SuDS) as part of its design and build.

These SuDS must be designed and built in accordance with standards published by Welsh Government and approved by the local authority acting in its role as a SuDS approval body (SAB). The SAB will then have the duty to adopt any compliant systems; serving multiple properties


Why have these regulations come into force?

Welsh Government has been looking to move away from traditional drainage solutions for some time as these techniques are designed to remove water away from developed areas with no regard for the drainage regime downstream or the quality of the water. What SuDS aim to do is mimic the natural drainage patterns of the area, which reduce the chance of flooding and pollution on the surrounding water bodies.


Schedule 3 of the  Flood and Water Management Act (FWMA) 2010 is the legislation that is driving the introduction of SuDS throughout Wales. All new developments will have to have approved surface water drainage systems on developments of 2 or more properties or that have a construction area of over 100m2 


SuDS - Welsh Government



If you would like more information about this process, please contact the SAB team:



SuDS application fee calculator

Please note: There is currently no fee for a SuDS Pre-Application

Further information

Welsh Governments Statutory standards for SuDS


Statutory standards for SuDS can also be found in the following:


CIRIA 753: The SuDS Manual


SuDSWales Website


Susdrain Website