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Floods Debate | SuDs

Aquacellcore p112

In January this year the government published its 25 Year Environment Plan, pledging to expand its use of natural flood defences and placing greater importance on sustainable drainage systems (SuDS).

The Department for Environment, Food & Rural Affairs (Defra) not only recommended SuDS – such as permeable surfaces, storage tanks and ponds – to reduce the risk of surface water flooding, it said it would consider changes to the National Planning Policy Framework (NPPF) and building regulations to reinforce its recommendations.

This seems like a significant change from reaching for a hard engineering solution as the first step, but should the industry be encouraged by promises in the 25 year plan?

Wavin product manager for stormwater management Martin Lambley believes the plan should be welcomed by drainage professionals, although he warns that there is still some way to go for the SuDS industry to grow. “There’s very clearly an appetite for change but it still seems frustratingly slow at the moment,” he says. “It doesn’t feel like everyone’s on a bus that’s going in the same direction.”

Sue illman pointing crop

Sue illman pointing crop

Illman: 25 Year Environment Plan is positive step

But SuDS specialist Illman Young Landscape Design CIC’s flood mitigation and resilience champion Sue Illman is optimistic that the government-backed shift towards SuDS solutions will have an impact.

“I’m feeling quite encouraged,” says Illman. “The government is taking the 25 Year Environment Plan as an overarching plan for departments and therefore looking at how that’s going to be dealt with when combined with, for example, natural capital accounting.”

Impact of Environment Plan

Illman feels the focus on SuDS in the 25 Year Environment Plan has had an impact on the latest version of the NPPF, which sets out the government’s planning policies for England and how they should be applied.

Illman is most excited that the NPPF includes reference to “multi-functionality”, something she describes as a “magic” word which encompasses the four key pillars of SuDS: using them to manage water quality and quantity; improve biodiversity and create better amenities for the local community.

Stephen o'malley civic engineers crop

Stephen o’malley civic engineers crop

O’Malley: SuDS add health and tourism benefits

Focusing on multi-functionality could lead to improvements in non-technical statutory standards, and advance environmental net gains, says Illman.

 “Put that all together and that sounds like something that’s pretty damn encouraging,” she adds.

Environment Agency senior specialist Hayley Bowman agrees, arguing the 25 Year Environment Plan will make it easier for SuDS principles to be adopted.

“[SuDS] is not going to be everywhere, it’s not going to work for every site, but I think it’s really encouraging to see that language now that we are looking for,” she says.

“The government does hold those principles very dear; we’re looking for betterment, we’re looking for net-gain principles and SuDS can really do that.”

For Chartered Institute of Water & Environmental Management head of policy Alastair Chisholm, environment secretary Michael Gove has helped give the plan authority – which means multi-functional SuDS have a chance to be taken more seriously.

“It does seem to be carrying quite a lot of weight and a big part of that has to be that the secretary of state at the moment is quite a big fish. He’s having a positive impact,” he says.

Brexit distraction

But Chisholm feels Brexit is taking up a lot of Gove’s attention, leaving him little time to focus on promoting SuDS and the 25 year plan.

“I’m not sure this is properly on his radar at the moment: he’s engaged with the really big, Brexit-related issues, and so I think there’s a job to do to raise it up his agenda slightly.”

Owen davies rb greenwich crop

Owen davies rb greenwich crop

Davies: Increased pressure to use SuDS

Civic Engineers founding director Stephen O’Malley adds that public health and tourism benefits from SuDS could help bring more people onside.

“I think those two mentions are not yet fully realised in the SuDS debate, the amenity element there is not officially high on that agenda,” he says.

But Floodline Consulting technical director Faruk Pekbeken has found that despite positivity in policy circles, SuDS principles have yet to be embedded.

He describes how developers can be reluctant to include SuDS such as ponds and culverts due to complications with schemes spilling over onto private land.

“Once you step outside the red line boundary of your development site and you’re looking at third party areas…you can understand why a developer says it’s far too complicated,” says Pekbeken.

“We find that even when it’s for the benefit of the community, you get resistance because it’s on somebody’s walkway, or it affects third party land.”

For local authorities, the government’s move towards a more natural flood management system has been welcome, but challenging.

In 2010 the government passed the Flood & Water Management Act, which put pressure on local authorities to aim for sustainable development when planning flood policies.

Royal Borough of Greenwich flood risk manager Owen Davies says the legislation increased pressure to use SuDS.

“It’s been a real steep learning curve. In 2010 we were thrown all this responsibility and suddenly we’ve got to understand what is going on with surface water and groundwater…we’ve got all these ordinary watercourses which we never knew existed and suddenly we’re trying to understand these and what they do, and how they work,” he says.

Martin lambley wavin crop

Martin lambley wavin crop

Lambley: Need for knowledge gap to be closed

Illman understands the pressure Davies and other council professionals are under. She refers to a recent survey of 12 local authorities showing that 80% of planning applications include an element of SuDS. However, how much was included varied.

“It’s a wide range, some of them are really struggling,” she says. “Where you’ve got a planning department that’s really proactive, where they’re running training sessions for developers and bringing them in and having the conversations, you’re getting good results. But where there are those who are just dealing with it as it comes in and not really pushing it or possibly are not at that stage in their policy cycle where their local plans might be slightly out of date… They haven’t got the tools in their kit.”

Despite this, Illman stresses that the situation will get better as the 25 year plan is implemented and changes to the NPPF trickle through.

Lambley agrees, adding he has seen an uplift in the sale of SuDS products. “We are seeing a real change in the way the tanks are being used within design,” he adds. “We’re starting to see a lot more smaller tanks dotted around which are much more localised, even within the development.

“Obviously the more the market expands and it is accepted…as a manufacturer we can tap into that.”

But one thing Lambley would like to see is a better awareness of SuDS across the industry. “I still feel like there’s a bit of a lack of knowledge, so I guess as an industry one of the questions is how do we address that around sustainable drainage? Because there’s clearly a lot of people with a lot of knowledge but they’re not spread out across the country.”

Environment Plan

The 25 Year Environment Plan is the government’s ambitious bid to leave the environment in a better state than when its ministers first came to power.

The plan outlines how to reduce plastic waste, plant trees to cut carbon dioxide pollution and most importantly, to work with nature to protect communities

from flooding.

It refers to the concept of natural capital, which is described as elements of nature that directly or indirectly bring value to people and the country, such as rivers which provide food and water.

The plan will be refreshed every five years and progress will be reported on each year, to make sure the UK is hitting its targets.

It is hoped this new level of scrutiny will help push further uptake of SuDS.


Debate participants

This report is based on a round table discussion which took place in London in June. The participants were:

Fiona Barbour global water practice leader for rivers and floods, Mott MacDonald

Hayley Bowman senior specialist, Environment Agency

Alastair Chisholm head of policy and communications, Chartered Institute of Water & Environmental Management

Owen Davies flood risk manager, Royal Borough of Greenwich

Ian George water management and resilience partner, Arcadis

Mark Hansford editor, New Civil Engineer

Sue Illman flood mitigation and resilience champion, Illman Young Landscape Design CIC

Martin Lambley product manager for stormwater management, Wavin

Darren Milsom programme manager, CH2M

Stephen O’Malley founding director, Civic Engineers

Faruk Pekbeken technical director, Floodline Consulting

Josh Rigby senior consultant, Waterco


Produced in association with

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Logo wavin connect to better cmyk

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