Retrofitting SuDS

Retrofitting SuDS

SuDS retrofitted into urban street

Drainage and sewer networks have a limited capacity. One of the challenges as towns grow and intense rainfall happens more often, is that these drainage systems can become overwhelmed, and cause flooding. Pipe networks can be upgraded to increase their capacity, but this is a very costly solution.

An alternative solution is to use SuDS to disconnect the existing drainage system from sewers or highway drains, and to direct it into a watercourse, or allow it to infiltrate into the ground.

Where SuDS are incorporated after the initial development of an area, or are used to improve the existing drainage situation, this process is known as 'SuDS retrofitting'.

This can be done at a range of scales, for example, rainfall from the downpipe of a house can be diverted into a green roof or raingarden, rather than the sewer system. During redevelopment of a town centre, runoff from pavements and roads can be drained into swales or permeable paving, rather than into an overloaded highway drainage network. Or runoff from a larger urban area could be diverted into a new storage area in a park.

Retrofitting SuDS provides an opportunity not only to remove rainfall from the sewer network, but also to remove concrete and hard surfaces. This helps to create green spaces and to make public spaces in towns and cities better places for people and wildlife to live.