The answer to the housing industry's concerns about space, or just a waste of good plastic? 

B&E hears from manufacturers about what could prove to be a revolutionary way to manage water.

LET’S FACE IT, there’s no rocket science behind Sustainable Urban Drainage Systems. They look a bit like beer crates, you bury them in a field and they fill with water. Easy. But if you listen to the manufacturers of these products you would think they were the best thing since sliced bread. Their exponents would have us believe Suds help to solve the housing shortage, protect towns and cities and can even reduce our water bills.

So what’s all the fuss about Suds, and what gets the manufacturers of these products so hot under the collar?
Although they had been used on the continent for 20 years or so, Sustainable Urban Drainage Systems, or Suds for short were introduced to the UK by Hydro International around 10 years ago. To begin with, planners were cautious about the products, but they are beginning to use Suds as space-saving way to manage rainwater runoff. Manufacturers have been quick to pick up on the potential market for the product, and most of the big pipe firms offer Suds alongside their traditional products.

Setting the standard

The Suds market is still in its infancy, and although there is currently guidance on planning and maintenance from Ciria, there is no formal standard for the products themselves. This might sound unusual for an industry as tightly regulated as drainage, which has a raft of regulations for other products such as waste pipes. For the moment though, contractors have to rely on manufacturers’ assurances about their products.

“It’s a bit of a Wild West situation right now and we really are the pioneers,” explains Marley Plumbing and Drainage category manager Ryan Hammond. “There’s a lot of responsibility for those companies that do make Suds to do the tests on their products and make the results available to their customers. Nobody’s gone hightech on them, as long as they meet reasonable performance requirements.”

The only discernable difference in the products is in the way they are manufactured. Marley, Hepworth and Hydro International make their products by extruding a honeycomb structure, which is then chopped off at the appropriate length and sandwiched between two end pieces. Other firms produce Suds by injection moulding sections, which are then clipped together.

Despite the different ways of making Suds, says Hammond, the end products are much the same. “I’m not sure there’s a huge advantage either way,” he says, “but I expect time will tell. When standards are developed for Suds, we will then see which products meet them.”

The politics of space

The impetus to incorporate Suds into developments has come from the government’s drive to meet housing targets. As developers are encouraged to build homes more densely, it follows that to save space there is also an impetus to manage rainwater more carefully.

Finding a means to manage rainwater might sound straightforward, but developers are faced with conflicting guidance from the top down. There is a drive by the Department of Communities and Local Government to build more densely, which in turn will push rainwater management systems below ground. However, the Environment Agency says it wants planners to incorporate other methods of rainwater management such as lagoons, into developments.

Only time will tell which method will prove the most favoured, although Suds sound a more viable option for developers, wanting to free up extra land for carparking.However, Hammond says it will take time to persuade the industry to break with tradition and switch to Suds. “There’s a great deal of work to be done educating designers,” he says. “If you’ve always created lagoons or attenuation ponds, it seems out of the ordinary to be putting crates into the ground.”

Wavin customer marketing manager, Denise O’Leary, says Suds perform as well as traditional techniques for rainwater management. “From the housing developer’s point of view, the driver for Suds will be that they are putting something into the ground that will give the same runoff effect as greenfield.”

O’Leary adds that Suds appeal to contractors over more heavyweight materials from a health and safety point of  view. “It’s much safer to be carrying plastic crate than moving large amounts of concrete around the site,” she says.

Hammond says Suds are making their mark as part of industrial developments. “The real advantage of it is in larger developments, such as warehouses, where there is a large quantity of water running off the roof,” he says. “They also go to where space is a premium, under a lorry park for example.” he says. “The last thing a developer can afford to do is to use a whole field to build a lagoon for storm water runoff.”

O’Leary believes the pressure to switch to Suds will come from the end user. “People feel that rainfall patterns are changing,” she says. “The general public is asking questions about rainfall it didn’t previously do.”

Considering the pressures contractors are under to provide a greater number of homes in a smaller space, while future-proofing developments against climate change and a possible increase in rainfall, Suds look like a plausible answer to their needs. How and when manufacturers convince designers to throw out their old ways of designing water management and adopt an underground approach, only time will tell. But the market for rainwater management, they hope, will be a buoyant one.