For generations, especially in the rainy old countries of the north, water hasn’t been something we’ve valued as much as we should have done. ‘Get the water away’ was the guiding philosophy of catchment and storm water management approaches, with it creating the minimum of inconvenience and damage in the process.

Now we are beginning to see the consequences of this policy. Widespread urbanisation of catchments in the last fifty years has ‘sealed’ huge areas. Rainwater that once filtered down into aquifers or dwelt in wetlands prior to being released into rivers is now rushed down through the system, with the result of periodic, damaging floods (think summer 2007) and shrinking water resources. Disappearing rivers is one consequence, the depletion of groundwater reserves as pumping exceeds recharge is another. Increased incidence of foul sewers overloaded with storm water, discharging into rivers and the sea, untreated, is a politically sensitive consequence of a changing climate and catchment management policies inherited from the last century. This is one of the main driving forces in the promotion of SUDS.

SUDS or Sutainable Urban Drainage Systems is one response to this set of problems. SUDS aims to mimic natural drainage systems in situations where development has replaced them. SUDS involve putting in place a range of possible measures that can be engineered into new developments or retrofitted into existing ones. They include elements as simple as water butts, through to permeable paving, green roofs, detention and wetland basins, retention ponds and swales (normally dry, shallow, open channels that slow the flow of water). Conventional drainage relies on pipes, culverted rivers, end of pipe treatment and when all else fails, discharge to sea or river untreated. It can also see (in storm conditions) clean rainwater (a valuable resource) mixed with foul water to create a much bigger problem for treatment and disposal.

The Environment Agency is encouraging the adoption of SUDS because they don’t contribute to flooding or pollution, encourage wildlife and provide wetland habitats that are visually attractive and offer recreational and educational amenities. They also husband water resources more effectively so that the risk of extreme flooding is reduced and water reserves are there to be drawn on in times of shortage. SUDS can also provide some treatment processes that costly end-of-pipe treatment works would otherwise have to deal with.

SUDS is a key element in the EA’s Planning Policy Statement 25 ‘Development and Flood Risk’. Within its risk-based approach, SUDS is viewed as a way of reducing risk through managing flood ‘pathways’ to reduce the likelihood of flooding. The purpose of Planning Policy Statements is to guide how councils, developers, water companies and other land and environmental managers approach the challenges of a changing climate and pressure for development.

SUDS is an approach that has the backing of government and an internationally proven track record. As well as offering a solution to the problems of stormwater and catchment management, it encourages greater green space provision within developments, with all the associated benefits that brings. The Green City initiative urges all involved to make the most of SUDS.