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Water companies reject sustainable drain systems


WATER UTILITIES and local authorities are flouting government guidance by refusing to implement drainage strategies that reduce flood risk, experts warned this week.

Developers are being allowed to install piped sewers on new housing estates when they should be installing landscaped flood control measures that hold water for longer.

Under last year's Planning Policy Guidance on building in flood plains PPG25 and Part H of the Building Regulations, it is assumed that sustainable urban drainage solutions (SUDS) will be used on new developments.

Government wants SUDS to be used instead of conventional piped sewers to drain surface water run-off. Water utilities are refusing to build them because they are not legally defined as 'sewer' by water regulator Ofwat, making it impossible for water firms to budget for SUDS in their asset management plans.

SUDS designs work by retaining water and allowing it to infiltrate into the ground, slowing the rate at which it flows into streams or rivers and preventing the sharp run-off 'peaks' that contribute to flooding, (NCE 21 March). They include grassy depressions known as swales, gravel filled infiltration trenches, porous paving, basins and ponds.

Utilities normally take responsibility for operating and maintaining sewers built by developers. But their refusal to adopt SUDS has forced developers to construct piped sewers instead, said House Builders Federation technical director Dave Baker.

SUDS cannot be funded under Ofwat rules because drainage systems must have an outfall pipe to be classified as sewer in the fifth edition of Ofwat's Sewers for Adoption, said Mike Waddington, policy adviser at water industry body Water UK.

Primary legislation is called for to align government drainage policy and water industry regulation, Waddington said. But Ofwat senior environmental programmes analyst Simon Walster said this would be a protracted process.

A working group involving the Environment Agency, the Department of Environment Food & Rural Affairs, Ofwat and water companies has been formed to report on the situation.

In the meantime, local authority planning departments are not taking action to enforce SUDS, said Hyder project director and chairman of the SUDS working party for Wales Roger Noden.

This is because most local authorities demand that developers pay them to maintain SUDS. Developers are unwilling to stump up for SUDS maintenance while water companies adopt piped drainage for free, Noden claimed.

By insisting SUDS are used, local authority planners could force developers to work out a solution, Noden added.

The Environment Agency is leaning on local authorities to take on SUDS until new legislation can be drafted. But the Local Government Association said SUDS are not a priority.

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