Sustainable drainage systems (SuDS) design

Sustainable drainage systems manage rainfall close to where it falls. They slow and store surface water, treat it, and release it at a controlled rate. Planning policy and Lead Local Flood Authorities expect them on most new development.

Odyssey designs SuDS as part of the site layout from the start, so that the space they need is allowed for before the masterplan is fixed. Depending on the site, this can include permeable paving, swales, rain gardens, basins and ponds, with below-ground storage where space is tight.

We assess whether the ground is suitable for infiltration, agree discharge rates with the Lead Local Flood Authority or water company, and size each feature using hydraulic modelling with an allowance for climate change. Designs address water quality, amenity and biodiversity as well as flood risk, in line with the CIRIA SuDS Manual.

We also prepare the maintenance plans and adoption details that authorities ask for, so that the system keeps working after handover.