Successful implementation of sustainable drainage systems (SuDS) requires greater collaboration and awareness across all built environment disciplines. This was one of the major discussion points at a SuDS panel discussion, hosted by ICE and Wavin, at industry conference Futurebuild.
The panel session was based on some of the key findings from ICE and Wavin’s recent design sprints in London and Leeds, held as part of their partnership on SuDS.
Panel speaker Paul Filkins, Engineering Manager at Taylor Wimpey Midlands, explained the need to “mix the disciplines up” in order to get the best results.
Sue Illman, owner and Managing Director of Illman-Young Landscape Design, who chaired the discussion, agreed: “SuDS is absolutely a collaborative exercise … it’s what we should be doing anyway.”
Panellist Martin Lambley, Product Manager – Stormwater Management, Wavin, recommended more SuDS education for potential practitioners. “It’d be good to see [SuDS] built into engineering degrees,” he said.
Collaboration to demonstrate value for money
However, the discussion revealed that greater SuDS understanding and engagement is needed among all stakeholders, including architects, planners, local authorities and residents. This is particularly important for managing costs and demonstrating value for money.
Filkins explained: “We can’t get our residents and the local parish councils to understand that these things don’t come free.
“Once we’ve actually built them and created these environments and habitats, we need people to take them over and pay for them … They’re interested in parkland, they’re not interested in what happens underneath.”
He emphasised how SuDS schemes can “give back to the community” and the need to raise awareness of benefits to residents.
SuDs ‘should be cheap, easy to maintain and stand the test of time’
But according to panellist John Rumble, Head of Environmental Resource Planning at Hertfordshire County Council, SuDS implementation doesn’t necessarily have to be expensive – as long as SuDS is considered from the start of a project and not treated as an afterthought at the end.
When SuDS is done well, it “should be cheap, easy to maintain and will stand the test of time,” Rumble said.
“It’s as expensive as you want it to be. If you do SuDs from first principles … you will probably get a relatively cheap system.”
Sewers for Adoption 8
The panel also discussed the upcoming Sewers for Adoption 8 guidance, expected to come into effect later this year, and particularly its potential impact on SuDS inspection and validation.
Rumble said that the guidance’s recommendations for water companies will raise new challenges and questions.
“The planning authorities need to be much, much stronger that what gets approved is what gets built … I think you’ll see something very different when the water companies get involved. It’s going to change things,” he said.
He warned that the lack of oversight can lead to failure of drainage systems upon meeting challenging conditions.
He said: “You don’t test [SuDS] until you get a storm and the right storm … that’s a lot of what-ifs. I do think there’s a bigger role for the regulator in the verification and inspection.”
Filkins agreed, saying: “[Currently] SuDS is never inspected by a body. It’s left to the developer and the contractor to self-police … When we get to Sewers for Adoption 8, we will actually get an authority – cradle to grave.”
‘Wales is doing it properly’
Rumble praised Wales for its current regulatory regime, but warned that the current movement towards separate systems in Scotland, England and Wales isn’t good for SuDS.
“Wales is doing it properly.,” he said. “Those of us in the industry are hoping that Wales is successful, and momentum will push the [UK] parliament to do it properly in England.”
He warned that there will be “a lot more risky sites coming up because the easy stuff has been done”.
“It’s going to be very interesting over the next 20 years,” he said.