What are Sustainable Drainage Systems (SuDs)?

Sustainable Drainage Systems (SuDS) are designed drainage features which mimic the effects of natural drainage systems, by temporarily storing rainwater close to where it falls, then slowly releasing it. This reduces the rate on run-off, by integrating surface water management directly within the site - rather than expecting storm water to be dealt with 'downstream', often with disastrous consequences.

SuDS are increasingly required components of new developments, but can also be retro-fitted into existing sites. Given the extent of existing built areas, which will be with us for decades to come, we need retrofit SuDS to help combat the increasingly severe and frequent storm events arising from climate change.


SuDS Components

SuDS components form a 'management train' which is multi-functional and includes:

  • water treatment: via filter strips and porous elements;
  • water attenuation: in green roofs, swales, ponds and basins;
  • conveyance: water is moved using only gravity, in swales and ditches;
  • flow attenuation: via control points.

Click on the 'Gallery of SuDS components' (right or below) to see some examples. Water is handled cleanly and safely - on the surface where possible - in a landscape designed for aesthetics, amenity and biodiversity.


Are SuDS expensive and difficult?

Absolutely not!

If a site is drained by a conventional system of gullies and pipes, terminating in a large, deep attenuation lagoon, the drainage system will be expensive, due to the amount of hardware involved (gullies, pipes, attenuation tanks, headwalls, fences) - and SuDS have a history in the UK of being expensively over-engineered.

But this need not be the case. As Landscape Architects, we integrate SuDS within the site landscape, from concept master plan to detailed layout and implementation. When properly considered from the outset, good SuDS design provides safe and low-cost opportunities to:-

  • significantly reduce capital and long-term management costs (SuDS development and maintenance are simply an aspect of the landscape development and maintenance);
  • substantially improve bio-diversity through habitat creation (which also helps with BREEAM ratings);
  • provide social, economic and health benefits, by creating beautiful, legible restorative places.

Why 2B?

Our 2B landscape team has undergone recognised CIRIA design training to undertake SuDS planning and design work, in collaboration with other trained professionals. We are committed to producing fabulous, functional and cost-effective SuDS designs for your projects.

Involve us ASAP!

The CIRIA SuDS Manual 2015 states "Provided that drainage is considered early enough in the outline design of a new development then there is no reason why SuDS should not become the norm everywhere.... Where SuDs are designed to make efficient use of the space available, they can often cost less to implement than underground piped systems".

We would be delighted to discuss your requirements, so do please get in touch - as early in your project as possible, and preferably before you have placed any buildings or roads!