Sustainable drainage faces credibility challenge

A new report from the Natural Step sustainable development charity identifies six areas, which need to be addressed. These include comparing life-cycle costs of SUDS and traditional piped drainage systems; increasing awareness about the multiple benefits of SUDS; incorporating the SUDS concept within appropriate legislation; establishing protocols for its adoption and maintenance; diverting funds to SUDS from other areas of public expenditure; and overcoming any technical shortcomings.

This report, supported by the Environment Agency and Yorkshire Water Services, is the latest initiative to raise awareness of the SUDS approach and break down barriers to its introduction in particular professions, notably highways engineering.

Since 1998, SEPA has been encouraging the implementation of SUDS in Scotland through a partnership between the Scottish Housebuilders Association, the water authorities, Scottish Executive, the Convention of Scottish Local Authorities (COSLA), and Lanarkshire Development Agency. This group worked with the construction industry’s research organisation, CIRIA, to produce a design manual for Scotland and Northern Ireland in March 2000. CIRIA now has a homepage with recent case histories including the 550 hectare Dunfermline Eastern Expansion site, which will be developed over the next 20 years as a mixture of industrial, commercial, residential and recreational areas.

Scottish planning advice recommends the consideration of SUDS applications as does the latest English planning policy guidance note 25 for Development And Flood Risk, published in July 2001, which also points out that amended building regulations are focussed on encouraging greater use of infiltration and other sustainable drainage systems.

According to CIRIA, drainage systems can be developed in line with the ideals of sustainable development, by balancing the different issues that should be influencing the design. Surface water drainage methods that take account of quantity, quality and amenity issues are collectively referred to as Sustainable Urban Drainage Systems.

These systems are more sustainable than conventional drainage methods because they: manage runoff flowrates; reduce the impact of urbanisation on flooding; protect or enhance water quality; are sympathetic to the environmental setting and the needs of the local community; provide a habitat for wildlife in urban watercourses; and, encourage natural groundwater recharge, where appropriate.

An introductory booklet and video on SUDS is available from the Environment Agency on request by email.