Guide

Sustainable drainage systems (SUDS) for business

Swales in sustainable drainage systems (SUDS)

A swale is a shallow drainage channel with gentle side slopes in the ground where water running off a site can collect and soak away.

Swales can be used to channel run-off from roads, yards and car parks where it collects into pools before soaking away. You can also use swales to carry water through a site.

Swales can run alongside roads so that run-off from the road surface can drain directly to the swale. You can also use them in the treatment of lightly contaminated run-off from hard standing around farmyards and farm roads.

When building a swale, you can include check dams to slow the flow of water. This allows the sediment to settle out. You can also use swales to carry water between sustainable drainage system (SUDS) features instead of using pipes. This can reduce the cost of construction and maintenance.

Swales can be used for linking SUDS dealing with run-off from individual sites and SUDS that manage the run-off from large areas.

See a diagram of how a swale works.