A case of clouded thinking?

Sustainable drainage systems could play a vital role in a range of water management uses. But the Flood & Water Management Bill going through Parliament is just not recognising their potential, says Bob Sargent.

The Flood & Water Management Bill, which recently passed Committee Stage in the House of Commons, has provided a valuable opportunity to address some of the issues affecting members of the Environmental Industries Commission's (EIC) Water Management Working Group.

The bill's origins lie in the floods experienced in 2007 in England, and the subsequent review by Sir Michael Pitt. The Pitt Review identified several weaknesses in the administration of flood risk management in England, and made many recommendations aimed at improving matters.

These were wide-ranging but mainly focused on the fractured nature of flood management, which involves a number of public and private bodies with various aims and objectives, and on the gaps where no lead authority could be identified.

The bill is intended to implement many of the Pitt recommendations that require legislative change. The 2007 floods were exceptional, but the management of surface water was one of the key failings identified. The bill proposes that local authorities should become lead authorities for management of surface water and that the Environment Agency (EA) should have a strategic overview.

EIC has been campaigning to improve the implementation of sustainable drainage systems (SUDS) for several years and the importance of these techniques for reducing surface water runoff and improving its management in urban areas was recognised in the Pitt review. The bill includes measures intended to allow better implementation of SUDS, though EIC is not convinced it will be successful in its aims.

SUDS manage rainfall in a more natural way. Instead of draining runoff away as quickly as possible to the nearest watercourse they slow down the process by reducing runoff at source - providing more storage in the system - and use infiltration and natural systems like wetlands to reduce and improve water quality. This results in less water arriving in rivers, and what does get there arrives more slowly and in better quality.

So SUDS can play a useful role in reducing flood risk in urban areas, but their use has been greatly hindered in England and Wales by legislative barriers. These have centred on how SUDS can be accommodated into the more traditional model of drainage.

Neither water companies nor local authorities are keen to adopt and maintain drainage which can include systems that are clearly not sewers, that could include a wetland, might collect runoff from a number of sources, and may not even discharge to a watercourse. Add to this the lack of agreed design guidance and maintenance costs, and it is not surprising there are problems. The bill proposes SUDS should be the drainage system of first resort - it will be necessary to show they cannot work at a site before considering anything else. This is a fine sentiment, but in practice the devil will be in the detail of what is considered unworkable.

Next, the bill proposes that local authorities should adopt and maintain SUDS systems. This is a crucial element, but for it to work local authorities - or any adopting authority - will have to have a source of revenue to fund the work.

The proposal is that funding will be released by moving the maintenance of private sewers from local authorities to water companies, and using the money saved to fund SUDS. Unfortunately, the local authorities do not actually do much of this work, so the saving is largely illusory. Without funding very little can happen, so the bill could fail to achieve its aims. EIC's Water Management Group is also disappointed that a more holistic approach has not been taken.

This is, after all, a flood and water management bill, and SUDS offer wider opportunities to manage water than just flood reduction. There is the quality issue, and many of our small urban watercourses are polluted by urban drainage.

Low stream flows can be sustained through slow discharge of infiltrated water, and there is the opportunity to develop water harvesting and reuse systems linked to SUDS that store water at source, i.e. near buildings, just where we need to provide water reuse opportunities.

None of these applications of SUDS are considered in the bill, despite the obvious water management implications and the potential for adapting to climate change they present. The bill focuses on the flood management aspects of SUDS only, a result of its origins in the Pitt Review.

In essence these failings are a reflection on the wider problem of there not being a water management authority with a grasp of the whole picture.

Responsibility for SUDS may, arguably, be best placed in a local authority, but that authority is not concerned with water supply, nor with the quality of our rivers. So the bill presents a solution that may not work for part of the SUDS implementation issue, and ignores much of the rest. The campaign continues!

Bob Sargent is vice-chair of the EIC's Water Management Sector Working Group, and director of Water Environment at Hyder Consulting. W: www.eic-uk.co.uk

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