Natural hazards such as storms, floods, extremes of cold and warm weather are forecast to increase as a result of climate change. The Institute for Public Policy Research released a report in 2019 highlighting that since “1950 the number of floods across the world has increased 15 times, extreme temperature events 20 times, and wildfires seven-fold”.
1 in 6 properties in the UK are deemed to be at risk of flooding, in England this equates to over 5 million homes and businesses (2.4 million properties from river or coastal flooding and 3 million from surface water -Environment Agency). ‘The EA are anticipating that spending on infrastructure, to manage flood risk will need to be in the region of £1bn annually, for the next 50 years’ (IEMA).
Population growth and urban sprawl have seen a rise in new development on floodplains and this is expected to double over the next 50 years (Draft National Flood and Coastal Erosion Risk Management Strategy for England). Reports of flooding in communities that may never have flooded before are more common and headlines such as ‘area set for a month’s worth of rain in a few hours’ are not so unusual. There will need to be clear guidelines for planners regarding how and where we build as new development will require greater resilience to a changing climate and its environmental effects.
‘Resilience’ and ‘adaptation’ are words that are now common place when describing the governmental approach to climate change and flooding. The Chair of the Environment Agency, Emma Howard Boyd said in a speech recently “We need to move away from talking about flood ‘defence’ as we cannot win a war against water and we cannot expect to build our way out of future climate risks with infinitely high walls and barriers.
In terms of flooding, ‘resilient infrastructure’ describes assets which have the ability to withstand rising sea levels and flood water, both now and in the future, allowing normal operations to resume quickly and our communities to continue to function after flood water has abated.
For areas that experience flooding, adaptation will require a new approach to flood risk management and living with water. Considering that we can manage flood risk to a degree (but not all flooding, always), risk management authorities need to be ready for the uncertain future which lies ahead.
Flood management schemes will continue to be required at critical sites which cannot easily be moved such as power stations, mainline railways, roads and gas terminals. There also needs to be an integrated approach to flood risk that is adaptable, uses natural processes, resilient engineering, relocation of assets away from risk and better planning of where infrastructure is built which can be sustainable into the future, not just installing large amounts of concrete.
If we look back at historical flood events in Carlisle for example, where the building of incrementally higher defences has taken place after large scale flood events, we can see the following has occurred…
- In 1968, 400 properties were flooded – flood management scheme built (Geographical Association).
- In 2005, 1800 properties flooded – a new flood management scheme was built, construction finished in 2010.
- In 2015, 2100 properties flooded – construction of an improved flood management scheme began in 2019.
This approach has proven effective up to the point where they are overtopped by the next flood event which is greater than design capacity – but how many times, realistically, can hard defences continue to be raised?
How will we adapt?
Where coastal defence schemes are considered unfeasible to build or maintain, letting the water in, setting back shorelines and restoring coastal environments is seen as a long term, sustainable approach to the effects of rising sea levels. This is highlighted in the Shoreline Management Plan for the West of Wales, which raises concerns over the future long-term sustainability of the coastal protection scheme at Fairbourne; a village situated on land which is reclaimed from the sea. This small village is being considered for decommissioning, with the area being returned to saltmarsh, raising the possibility of the displacement of 1000 residents.
Blue/Green Infrastructure, Sustainable Drainage Systems and Natural Flood Management are hot topics in the media these days, and seek to promote a more natural water cycle. In towns and cities, traditional drainage funnels surface water quickly to sewers, streams and rivers, which can lead to capacity quickly being exceeded. By making space for water in our new developments and not simply trying to get rid of it quickly, we can manage it in a more sustainable way.
Adaptation and resilience may take many approaches and The Lake District National Park ‘Routes to Resilience’ programme has seen £3m spent on the restoration of public rights of way that were damaged during flooding in 2015, the programme includes the restoration of 94 bridges, 65 public footpaths and 44 access structures. The community will be more resilient both physically and commercially to the effects of flooding in the future as a result of the restored access.
Two Cumbrian schemes in particular at Gooseholme in Kendal and the River Eamont at Pooley Bridge will see old, multiple span, stone bridges which were damaged during flooding in 2015, replaced with modern single span designs. These new installations will allow high river levels to maintain flow without obstruction from in-stream pier supports, reducing the forces on the structure in more extreme weather conditions.
There needs to be a shift in public awareness to the uncertain effects that climate change will have, and the societal expectations of how increased flood risk will be managed in the future. A change in public perception is required, away from the idea that flood walls and barriers are, and will be, the only way to protect communities from flooding, to a more sustainable and adaptable approach moving forward.