Extreme weather and changing flood risk: how to reduce exposure

Written by SLR's Martin Baines & Dan Watson

Back in January, prolonged rainfall resulted in flooding across parts of Southwest England; however, despite this, there has been relatively little flooding in the news in the UK over the last winter. In fact, you may have noticed that while in the winter of 2021 / 2022 there were a succession of big named storms which resulted in significant rainfall, including three in one week (Dudley, Eunice and Franklin) this year we have had only one. As such, as we head into spring, instead of flooding, parts of the county are preparing for drought. This just demonstrates the difficulty in trying to understand and predict extreme events which are chaotic and random in nature, and which are linked to global weather patterns and sea temperatures far beyond our shores.

Despite the experience of this last winter, historical records and research indicate the weather in the UK and globally is becoming increasingly extreme. Recent research led by the University of Bristol* indicates that annual damage associated with flooding, which already stands at £740M in the UK, will still increase by up to a fifth over the next century even if all international pledges to reduce carbon emissions are met.

Much of the discussion on how best to manage this relates to the provision of flood defences, or the rights and wrongs of locating new development in riverside locations that are vulnerable to flooding. There remains however a large stock of existing property right across the UK that is known to be vulnerable to flooding and for which there is no economic argument for publicly funded flood protection. Insurers are rightly wary of providing flood cover for such properties, arguing that it simply does not make commercial sense.

What then are the options for property owners caught in this situation?

SLR has been working with a number of different insurers and insurance brokers in the UK and Ireland to enable them to provide flood cover for properties in higher-risk locations. This will typically involve additional review and assessment to clarify the risk at a site-specific level. Once this is complete, we then work with the property owner to help reduce their exposure to flooding. Flooding might occur from rivers, the sea, rising groundwater, rainfall, or the failure of flood defences.

Typically, this might include one or more of the following recommendations:

• Targeted changes to how the owners use their space. For example, can they move valuable equipment such as computer servers to less vulnerable parts of the building?
  
• Strategies for making the building more resilient to flooding through the use of measures such as impermeable flooring and wall finishes, the removal of soft furnishings (which would be damaged by contact with flood water) from the low parts of the property, and raised electrical sockets.
  
• Measures to prevent flood water from entering the property such as flood boards on doors and covers on air vents.
  
• Plans to respond and make temporary changes in advance of flooding in response to flood warnings and alerts issued by the relevant regional agency. This might include moving things to higher parts of the building or other sites or erecting and closing flood barriers.

By working with the property owners, we are often able to help them to reduce the probability of the flooding of their buildings or to reduce the scale of damage (and cost) that occurs in the event of a flood. Appropriate planning can also improve the speed of recovery following a flood event. When appropriately documented this often gives the insurers the confidence to provide cover for any residual risks.

In many cases, these measures provide a pragmatic solution to help businesses, industries, and homeowners to manage their risks while continuing to function on a day-to-day basis. At the same time, we are able to provide advice concerning longer term strategies for managing flood risks which are projected to grow over time as a result of climate change. This advice can then be factored into their medium- and long-term plans.

• ‘A climate-conditioned catastrophe risk model for UK flooding’ by Paul D. Bates et al in Natural Hazards and Earth System Science