February 2020 was officially the wettest February since records began in 1862, with storms Ciara, Dennis and Jorge sweeping across the UK. Consequentially, extreme flooding has been observed across the country, causing severe impacts in the Midlands, Wales, Cumbria and Yorkshire. New flood defence infrastructure is said to have provided protection for over 200,000 buildings, but not all prevention measures were successful. The historical village of Ironbridge in Shropshire was completely evacuated after temporary barriers were buckled by the volume of water within the River Severn. In the midst of the downpours that have raged across the British Isles, an additional £4bn was pledged as funding towards flood management, but how can we expect this to be distributed and is it really enough?
Met office research using a high-resolution climate model of the UK indicates that with increased rainfall intensity under climate change scenarios, sewer flooding volumes, flooding frequency and pollution events are likely to increase 1. In order to mitigate against the detrimental impacts that increased sewer flooding has on cities and towns, predictive studies must be undertaken in order to understand where the impacts are likely to be most felt. Due to artificial modification of river channels, flood plains and land cover, drainage patterns have become increasingly challenging to predict and understand. It may well prove necessary to re-assess the way in which we test systems using hydraulic models, for instance broadening the range of extreme weather events and possibly reviewing climate change uplift factors. In conjunction, it is more important than ever that the UK takes stock of its existing infrastructure. Studies in Wales have found that less than 13% of barriers constructed along the River Afan in the last 200 years have been officially recorded [1]. In collating and reviewing data from previous water management schemes within the UK, we can ensure that all future decisions regarding future flood management are well informed.
By 2040, it is predicted that the number of vulnerable residential properties exposed to flooding will increase by 40% to 1.2 million, under a 2ᵒC increase in global temperature. Existing predictive studies have incorporated possible mitigation options and tested them in combination with a variety of population growth projections and increases in rainfall intensity 2. These found that if current levels of adaption continue, expected annual damages are predicted to rise by 50% under a 2ᵒC increase scenario. From a review of existing expenditure, the most significant risk for flooding is fluvial. Given that so many major towns and cities have large watercourses transecting them, this will have a serious impact on urban drainage flooding, thus it is more important than ever to increase integrated catchment modelling.
In 2010, the UK government published the Flood and Water Management Act (FWMA), which provides guidance on how to better manage flood risk3. In 2017, the Department for Environmental, Food and Rural Affairs (Defra) evaluated this to assess its effectiveness. Access to government funding was criticised as being restrictive, and over bureaucratic in comparison to capital funding for similar sized projects in other industries, such as transport infrastructure. Additionally, it is likely that continued changes to flood insurance and compensation schemes will arise in the wake of major flooding incidents. The government currently redirects the public to the National Flood Forum for advice on household insurance, and the Flood Re scheme attempts to make flood insurance more affordable. Nonetheless, properties in high risk zones are likely to pay expensive premiums in order to obtain flood cover. Figure 1 illustrates the distribution of pledged money by the government to deal with flooding issues, such as those seen in February 2020, however this presents a cause for concern in some locations. Several constituencies in the Midlands, including Shrewsbury and Atcham, and Telford are set to receive very little.
UK policies have shifted towards adaptations for living with flooding, following suit the outlooks of other countries. As a result, it is likely that there will be an increased focus on long term recovery and improving flood resilience within communities. In uncertain times of a changing climate, adaptability is more important than ever. On the global stage of flood risk management, the UK appears advanced; favouring catchment orientated approaches which deliver bespoke management strategies and developing a variety of legislation which attempts to reduce the impacts felt by flooding. However, moving forward it is crucial that our approach to modelling flooding, flood defenses and mitigation schemes evolve in advance of the growing pressures presented by climate change.
2. https://www.icevirtuallibrary.com/doi/10.1680/jensu.15.00030
3. http://www.legislation.gov.uk/ukpga/2010/29/contents
4. https://www.carbonbrief.org/mapped-where-four-point-four-billion-being-spent-flood-protection