Flooding is one of the UK’s key climate red flags. Extreme weather events are becoming more frequent and impossible to ignore, providing compelling evidence of a rapidly changing climate that’s measured in damage to property and danger to life, rather than future temperature increases and more abstract figures around carbon emissions.
Winters punctuated by heavy rain and flooding and summers swinging between drought and flash floods have provided a wakeup call to the readiness of the nation’s infrastructure to cope with these extreme weather events, underlined by the overwhelming cost of picking up the pieces. Damage to property, buildings, and transport infrastructure costs the UK £2.4 billion every year, but the impact is compounded every year that we leave the problem unchecked. Each year of flooding puts a decade-long downward pressure on the economy worth at least £6.1 billion.
Clearly, the problem isn’t just one for those directly affected. Uncertainty around flooding and other climate impacts influence everyone’s access to capital, upsetting markets from mortgages to insurance. Allianz, one of the world’s biggest insurers, is the latest to raise the alarm, warning that there will come a point where insurers will no longer be able to offer cover for climate risks.
The UK’s urban communities are directly in the line of fire, with recent cycles of drought and flash flooding underlining that our drainage infrastructure is not fit for a future defined by extreme weather. Much dates back to the Victorian era and can’t cope with increasing populations and more extreme weather events. As the Government undertakes a huge commitment to housebuilding, incorporating advanced flood management solutions into new developments is no longer optional – it’s essential.
A broken water cycle
When it comes to flood defences, nature is the best in the business. Naturally permeable environments allow rainwater to be absorbed and returned to the water cycle at a controlled rate, preventing the accumulation of too much water in one place. Some removal of natural permeability is impossible to avoid when a new development or community springs up, but we can’t keep interrupting the water cycle and expect outdated drainage systems to pick up the pieces. Stormwater management strategies need to be at the heart of these projects, because they’re crucial to their long-term resilience. Developers need the tools to mimic the natural water cycle with sustainable, futureproof drainage.
Extreme weather isn’t going anywhere, and nor are population growth or urbanisation. What we do have the power to change is reducing the impact of new developments on the natural water cycle. It’s time to build the ability to store rainwater and return it to the environment at a controlled rate into our new and existing communities.
Super SuDS
To ensure new projects are resilient in the face of a rapidly changing climate, we need to put water first, taking a holistic approach that learns from the natural environment. It’s not just a case of building bigger sewers and drainage infrastructure; new developments must implement sustainable drainage systems (SuDS) as standard if they’re to weather the storms to come.
SuDS use a mixture of natural and human-made solutions to mimic and restore the natural water cycle, helping to prevent developments from being overwhelmed by extreme rainfall. The solution will be different for every project, and primarily natural elements such as ponds, swales and tree pits can make developments more resilient and more appealing to potential home buyers. These systems combine soil and other natural elements with artificial storage tanks, but incorporating more innovative human-made solutions is becoming increasingly important as the rain keeps coming. Wavin’s Aquacell NG is one example – this modular attenuation tank is installed underneath a development where it collects rainwater and releases it back in a controlled manner. The tank has been created for quick and simple installation, while the modular design ensures it can adapt to fit the space on site.
This human-made grey infrastructure has a vital role in supporting the green initiatives above the surface. By providing robust protection against stormwater, grey solutions enable the green to add to that resilience but also to make our communities more desirable places to live. The benefits of adding trees, ponds and similar features go far beyond protecting us from flooding – they make for cleaner air and healthier environments. Access to green space is a priority for many home buyers and can add significant value to a new development.
Policy progress
More and more developers are recognising the need for sustainable drainage and incorporating systems into new projects, but the scale and speed of the change needed means the best intentions of the industry aren’t enough. Policymakers have begun to make the right noises in recent years, and Schedule 3 of the Flood and Water Management Act 2010, which would mandate the installation of SuDS on large new developments before they can connect to public sewer systems, was slated for implementation in 2024. However, progress has been slow, and there remains a lack of clear guidance on when it will be brought into effect.
Biodiversity net gain (BNG) legislation, which requires new developments to demonstrate how they will achieve a 10% net gain in biodiversity or habitat, has made more progress, having come into force in February 2024. However, it’s not clear how BNG will sit alongside the Government’s new Planning and Infrastructure Bill, which allows developments to pool contributions in a Nature Restoration Fund to meet environmental obligations faster.
Clarity is key in the legislative push for SuDS and urban resilience, but there’s another element that will maximise the impact of both policies: education. The developers charged with implementing SuDS need to understand their value, how to find the right approach for their project, and how to communicate the added value to buyers. For example, they may not be aware that implementing green SuDS can help them meet their obligations to Schedule 3 and BNG.
A more resilient future
Extreme weather isn’t going anywhere, and flooding will keep harming the UK unless we begin to close the water loop and restore the environment’s natural flood defences. New communities and developments are the perfect opportunity for the start of a new status quo that embraces sustainable drainage on a national scale. The right way forward is a holistic and collaborative approach, one led by an informed and empowered industry and underpinned by clear, forward-thinking policy.
For more information about SuDS, visit https://wavin.com/gb/solutions/stormwater
