Do I need permission?
From 7 January 2019, all new developments of more than one house or where the construction area is of 100m2 or more will require sustainable drainage to manage on-site surface water.
Surface water drainage systems must be designed and built in accordance with mandatory standards for sustainable drainage published by Welsh Ministers.
A copy of the Statutory National Standards for Sustainable Drainage Systems (SuDs) is available on the following link:
These systems must be approved by the local authority acting in its SuDS Approving Body (SAB) role before construction work begins. The SAB will have a duty to adopt compliant systems so long as it is built and functions in accordance with the approved proposals, including any SAB conditions of approval.
Construction work which has a drainage implication may not be commenced unless a drainage system for the work has been approved by the Sustainable Drainage Approval Body.
Construction work is defined in Regulation meaning anything done by way of, in connection with or in preparation for the creation of a building or other structure, and construction works has a drainage implication if the building or structure will affect the ability of land to absorb rainwater. It should be noted, and for the avoidance of any doubt, anything that covers land, such as a patio or other surface is a structure for the purposes of approval.
More information about SAB