Flooding experts have reacted with disbelief to government plans to create a legal loophole which will let developers avoid building sustainable drainage systems (Suds) on new projects.
The loophole would sidestep new national standards that have been proposed by the Department for Environment, Food and Rural Affairs (Defra).
The Flood & Water Management Act 2010 ordered that all construction work with drainage implications must comply with new national standards for Suds.
Under the Act, local authorities must take on the role of Suds Approving Body (SAB) and judge proposed projects against national Suds standards.
The Act instructs SABs to refuse planning permission for projects which do not comply with the standards. Introduction of the standards has been repeatedly postponed and their contents are still unknown (NCE 6 May).
But NCE can reveal that Defra is now proposing that where developers can demonstrate that Suds are disproportionately expensive, they can build a different drainage solution agreed with the local SAB.
Cambridge City Council sustainable drainage engineer Simon Bunn said the proposal undermined the Flood & Water Management Act and encouraged developers to avoid installing Suds.
“I would think those that really haven’t got a handle on how you can make Suds cheaper than traditional drainage would be continually applying for this [waiver],” he said.
“I would think those that really haven’t got a handle on how you can make Suds cheaper than traditional drainage would be continually applying for this”
Cambridge City Council sustainable drainage engineer Simon Bunn
A lead local flood authority official from the south of England said he felt Suds should be made compulsory until they become more widely accepted and used.
Only when developers are used to building Suds should a get-out clause be offered, he said.
He said many local authority flood officials were “up in arms” about the proposal.
A Defra spokesman said the proposal could apply in situations where “site-specific conditions” make Suds more expensive.
But Bunn said that in most cases Suds would be the cheaper option, unless they were left until late in the design process.
“You can do them cheaply if you get in there first and design them right,” he said.
“Not a question of cost”
Drainage expert and former ICE president Jean Venables said the need to use Suds should not be reduced to a question of cost.
“Suds should be viewed as having diverse benefits across many sectors, and it would be very detrimental if this proposal went ahead to scope out only on cost to the developer,” she said.
“This is not a sustainable approach.”
Venables said a cost comparison between Suds and traditional drainage could fail to take into account the wider social and environmental benefits of Suds.
Defra said it will further develop its proposal before putting it to public consultation.