In the UK we are positioned in the firing line of Atlantic weather systems and the Association of British Insurers has recently warned that, alongside increases in rain storm intensity, we should also prepare ourselves for more damage from destructive wind storms. Additional risk exists in relation to the impact of heatwaves. Flooding is perhaps the most frequent and familiar to the UK public, though financial impact of wind storms can be greater and the death toll is typically highest from heatwaves.
Obviously the ultimate aim should be to slow if not stop the emission of anthropogenic greenhouse gases such that these manifestations of climate change are avoided. But equally we need to ensure that our built environment is resilient to these impacts as far as possible.
The UK is in the midst of a housing crisis, which lead to the last government setting a target to build a million new homes by 2020. Incorporating resilience is easier with new build, particularly on greenfield sites where cost and availability of land allows for greater use of landscape features and unrestricted design to optimise resilience. It is vital that in building these new homes, and supporting infrastructure, they are properly conceived and constructed with a less stable and predictable climate in mind.
Aside from new build, a far bigger challenge exists in what to do with the vast majority of our existing built environment, developed decades or centuries ago with little or no consideration of resilience against storms and heatwaves. For many who have been flooded in recent years, sometimes a number of times, this is an all too present challenge. They often cannot move, insurance, if obtainable, can at best repair but little more, so retrofitting resilience measures is a sensible, cost-effective option.
The Chartered Institution of Water and Environmental Management (CIWEM) is currently helping to develop awareness, standards and codes of practice to ensure that when property flood-resilience measures are put into homes and business premises, this is done to a high standard to help keep water out or speed up the rate at which a building can be reoccupied following a flood. With insurers on board, the prospects to deliver real improvements in property flood resilience look positive.
Far too many people do not know they’re at risk of flooding. While most are likely to recognise risk of flooding from rivers and the sea, more people are likely to be affected by surface water flooding that occurs as a direct result of heavy, intense rain storms. We should be building and retrofitting our towns and cities to handle this flash flooding more effectively.
While traditionally the approach has been to pipe water away to the nearest river, this can cause problems. Firstly, as with much of the built environment, drainage systems can be decades or even centuries old, and are increasingly overloaded by new development and the increasingly intense rainfall. Secondly, by draining quickly into the nearest river, this can increase the risk of flooding to communities downstream.
The answer is to make our drainage systems better able to store water and let it drain away slowly, effectively removing the “flash” element from the flooding equation. CIWEM has been championing sustainable drainage systems, which do this by using a wide range of approaches from green roofs, permeable surfaces, ponds or underground tanks to store the water.
Designed at an early stage in a development, they are cost effective and can deliver a host of wider benefits, not least making towns and cities greener and more attractive. We are currently working with government to make sure policies and guidance work to mainstream this approach, and we are hopeful of real progress in the near future.