Soak Up Solutions to Flooding - By Lynn Hill
As extremes of weather caused by the climate crisis continue to take hold, flooding is increasingly becoming an issue across the UK. This brings the heart-breaking images we see all too often, where homes and businesses become engulfed in water. Flash flooding is a major cause of this, where torrential rainfall overwhelms drainage capacity and results in streets and neighbourhoods becoming submerged.
Flooding can be devastating. Homes and businesses ruined; disruption to our roads and travel; and tragically - even lives are lost. Environmentally, it causes the destruction of wildlife habitats; farm crops destroyed; and the spreading of pollution by contaminated flood water.
We are not powerless and we can play a very positive role in the solutions to the environmental crisis we face.
Of course, our governments have a vital role to play in addressing these issues through environmental policy. But if you think of all the households across Britain and the vastness that all these gardens create - we can begin to see a glimmer of potential. There are over 29 million homes in the UK. What vast potential we have as home owners in the fight against flooding!
The key word here is ‘permeable’. Permeable surfaces absorb water, it allows water to flow through it. So much of our built environment is made of hard surfaces. Roads, paving, driveways, patios. Most of which are ‘impermeable’, leaving the water nowhere to go but run off… and when it rains, water has to run somewhere.
So, what’s the solution? Thankfully there is a growing number of options for the environmentally friendly landscaper - options that can be adopted by anyone wishing to create garden and landscape spaces. Driveways are often the biggest culprit, with their large expanses of hard surface. They are great for parking, but terrible for drainage. This is why I love products like ECCOgravel, which bring the best of both worlds. With a stable surface that you can even walk on in high heels, it drains away beautifully, making it perfect for Sustainable Drainage System (SuDS) compliance.
For the proactive house builder, the inclusion of Sedum roofs can have a dramatic effect. They retain stormwater, which helps avoid our drainage systems becoming overwhelmed. Green roofs can reduce runoff by 60% to 100%, depending on the type of system used, as moisture is captured in the media or vegetation and will eventually evaporate from the soil surface, or be released back into the atmosphere by transpiration. Green roofs also contribute to biodiversity and habitat creation in our built environments, which desperately need more greenspaces. A further benefit is the increased lifespan of roof membrane by protecting it from solar exposure and ultraviolet radiation.
Manufacturers, suppliers, contractors, designers and clients. Together we can (and are) taking the lead by developing products that are much more environmentally friendly, that contribute to the
solution rather than the problem, making them easily available and affordable. We can shout their benefits from the rooftops, making people aware of their existence and how they can use them.
Designers being knowledgeable and specifying as and where they can, contractors making a habit of incorporating porous surfaces as standard, clients raising the bar and specifying that they want it this way. All these actions result in a society that is informed and engaged.
This is the collective future I know we can foster.
‘Measures to cope with the impacts of extreme weather are urgently needed’… these are the words of the UK Government’s official Climate Change Committee. We also see UK insurers warning that households and businesses in some areas could find themselves uninsurable if action is not taken. We have everything to gain by adopting sustainable environmental practices…. and so much to lose if we don’t.
Lynn’s top tips for reducing the impact of flash flooding and reducing rainwater runoff – tips that anyone can implement.
● Keep as much of your garden space as permeable as possible. The best is planted areas, or even grass. If you do need hard surfaces try to keep them to a minimum and use permeable products like ECCOgravel.
● Think about where hard surfaces will drain too. There are regulations across the UK relating to SuDS, which requires us to manage water in our gardens and avoid it flowing into streets,
neighbouring properties or sewage systems. Soil is like a sponge, so draining into a flower bed is often ideal, and it helps you with the plant watering too.
● Grow plants. Plants are great at sucking up water and they release it back into the atmosphere through a process called transpiration.
● Bare soil can compact under heavy rain, which can lead to nutrients and topsoil running off and ending up as pollutants in watercourses. So, try to avoid having bare areas, plant if you can or use ‘green manure’ (eg. mustard seeds) for a temporary fix.
Lynn Hill is a leading Scottish garden designer with expertise in sustainable design and its application to greenspace. A Pre-Registered Member of the Society of Garden Designers, she is also an Associate Designer with BALI (British Association of Landscape Industries); the Chartered Institute of Horticulture and the Scottish Ecological Design Association.www.lynnhillgardendesign.co.uk