Water butts are an easy way to slow the flow at home. We recommend opening the tap in winter, or ahead of expected heavy rainfall, to help them act as mini leaky dams in the event of flooding. We asked Lorna to tell us about the smart water butts she’s helped to develop – so that residents don’t need to manually open the tap!
At present, these smart water butts are still in development, and are being installed by LLFAs (Lead Local Flood Authorities) and Water Companies (aiming for large scale installations in one area, to mimic the flood alleviation effect of a storm tank, but at source, and with added benefits), rather than available to individuals.
For the past five years I’ve been part of a team developing a smart rainwater management system which can be deployed at any scale. We call it Intellistorm®.
Intellistorm® operates autonomously, with a mini computer instructing an actuated valve to open or close prior to rainfall to make capacity for the storm. The Intellistorm® system takes information from the weather forecast to calculate how much water to release.
They’re essentially a smart, dynamic version of a leaky water butt as described in Stuart’s blog Retrofitting a water butt as a ‘mini leaky dam’ for storm water attenuation, but in addition the Intellistorm® accurately calculates how much water to release and delivers data on how much water has been held back.
We’ve mostly deployed the system on 270 litre water butts and installed them on downpipes at people’s houses, working with water companies who have funded pilot studies to understand the potential for this technology.
We’ve learnt a lot, not just about how best to design and construct the control kit but also about about conducting the customer engagement, installation and follow-up communications.
Results from our latest pilot project, in North Devon, showed that the 34 smart water butts released total stormwater attenuation volumes 19 times greater than the volume of the tanks installed. This level of performance could not be realised in distributed, plot-scale systems without dynamic management. Data from this trial shows that without our intervention, most systems would have filled once, and then remained full, as they were not used for greywater by the homeowners.
They were installed in Combe Martin, where combined sewer overflows operate more often than they should due to excessive surface water in the sewerage network. The aim was to understand how much water they could hold back, which was 5,000 litres each, or altogether 108m3, over the course of a year.
There is, of course, a lot of work to engage with communities in order to install these at scale. But in a sense, that is also part of their appeal. Water companies have historically dealt with problems ‘at the end of the pipe’ with storm tanks below car parks and lots of work on buried infrastructure which goes on without most people being aware of it. It becomes the water company’s problem – and the solutions are all things the water companies does ‘to’ a community, not ‘with’ them.
Of course, that’s the beauty of SuDS. Smart water butts enable communities to be part of the solution to flooding and pollution – and they get a new water butt for the garden to boot.
For the water company, it’s an opportunity to have a face-to-face conversation that they rarely have with customers. Most of us sleep under a roof. Plenty of people have a paved-over front garden or a conservatory, extension or a patio. We’re all contributing to the increase in surface water, which is further fuelled by climate change and growth. So it makes sense to enlist all of us to do our bit to put it right.
Our experience is that many people are happy to help.
Smart water butts work best in smallish catchments with typically flashy responses to rainfall. They work well in constrained urban areas where space for a new storm tank is tight. They work well in conjunction with other sustainable drainage features – for example, overflowing to a swale or raingarden. And they are ideal in places where the authorities need to engage with communities – like in Ilkley, for example, where the river has been designated as bathing water but is not yet meeting water quality thresholds. And I’m sure there are many others.
They also work well as dual benefit attenuation and water conservation assets; for example, providing water to flush a toilet, which reduces potable water use and simultaneously creates capacity in the tank.Future projects for us include installing Intellistorm® on large attenuation assets or as part of the sewerage network itself.
Lorna Devenish
Market Development Manager, New Technology Systems, SDS Ltd.