We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use forestresearch.gov.uk, remember your settings and improve our services.
We also use cookies set by other sites to help us deliver content from their services.
The cost of flooding to the national economy in England and Wales is estimated to be £270 million a year. Following the Pitt review of the 2007 summer floods, local authorities are responsible for coordinating flood management.
Sustainable urban drainage systems (SUDS) are an increasingly important part of our green infrastructure. SUDS minimise surface water run-off and flood risks in an environmentally friendly way by mimicking natural water systems such as ponds, wetlands, swales and basins. SUDS can involve various ‘green’ engineering options such as infiltration trenches and filter drains, in order to slow water flow rate to reduce flood risk, whilst managing pollutants on site. SUDS offer neighbourhoods multiple benefits, including attractive planting features, and increased biodiversity whilst helping to ensure adaptation to climate change.
SUDS are also applicable to brownfield sites and techniques can be adapted to deal with a lack of space, poor soil infiltration, soil contamination and enhance and maintain biodiversity and wildlife.
The primary functions of trees, vegetation and soils are to aid in water interception, storage and infiltration while increasing evapotranspiration potential. Not all sites have the potential for open green spaces and trees, especially in highly urbanised areas where soil conditions restrict the amount of urban canopy cover. Floods usually occur during and after major storm events after canopy storage has been exceeded and although trees reduce runoff they are not effective at flood control. In contrast, tree planting on floodplains upstream of urban areas can significantly reduce flood risk.
SUDS can comprise one or more structures to manage surface water runoff. A combination of techniques using the ‘management train principle’ helps alleviate the pressures on a drainage system. These will often incorporate traditional underground drainage systems. Some SUDS techniques involve vegetation and water storage (ponds) encouraging green space in urban areas whilst other techniques are engineered solutions below ground level. The SUDS involving green space include controlling the water at source through transpiration in trees and vegetation, green roofs, infiltration trenches and filter drains, swales and basins, and ponds and wetlands. Green space provision will need to be considered alongside increased storage thus utilising sustainable drainage techniques.
Public perception surveys have highlighted several recommendations for the design and management of SUDS that address public acceptability:
Design:
Operation and maintenance:
Aspects of technical design that should be addressed include:
As a result of a history of flooding in the area, Oxfordshire County Council has made sustainable urban drainage systems (SUDS) an integral part of the planning process in developments throughout the county. Developments have featured a range of alternatives to traditional drainage, such as balancing ponds, wetlands and swales. Each development aims to make sustainable drainage into an attractive feature that can also bring additional benefits such as increasing biodiversity or introducing traffic calming measures.
Further advice on planning and designing SUDS can be obtained from ‘A Dos and Don’ts Guide for Planning and Designing Sustainable Urban Drainage Systems (SUDS)’ from The Scottish Environment Protection Agency.
There are a variety of resources available from Institute of Civil Engineers (ICE) on sustainable urban drainage.
Cookies are files saved on your phone, tablet or computer when you visit a website.
We use cookies to store information about how you use the dwi.gov.uk website, such as the pages you visit.
Find out more about cookies on forestresearch.gov.uk
We use 3 types of cookie. You can choose which cookies you're happy for us to use.
These essential cookies do things like remember your progress through a form. They always need to be on.
We use Google Analytics to measure how you use the website so we can improve it based on user needs. Google Analytics sets cookies that store anonymised information about: how you got to the site the pages you visit on forestresearch.gov.uk and how long you spend on each page what you click on while you're visiting the site
Some forestresearch.gov.uk pages may contain content from other sites, like YouTube or Flickr, which may set their own cookies. These sites are sometimes called ‘third party’ services. This tells us how many people are seeing the content and whether it’s useful.