Storm Dennis floods: how bad are they and what is being done?
How severe are the latest floods?
Storm Dennis is believed to have caused the worst winter floods in recent times, in part because the rain was so widespread but also because it has fallen on ground already saturated from Storm Ciara the previous week. Storm Dennis affected huge swaths of Britain, from the Scottish Highlands to the Cornish coast and large parts of Wales and Northern Ireland. It triggered a record-breaking number of Environment Agency flood warnings and alerts in England on Sunday.
Did flood defences fail?
The Environment Agency says its flood defences – both permanent and temporary measures – are working. It says that as many as 20,000 properties have been protected from storms Ciara and Dennis due to these measures. However, Britain has experienced an exceptionally wet winter and many rural areas, including towns and villages, have been left vulnerable to the higher river levels and saturated ground. Also, physical flood structures are only one part of the armoury.
What more could be done?
Flood barriers are a small but important part of the protection from devastating storms. Experts say that while Britain can never be fully flood-proof, much more could be done to better protect those in vulnerable areas. One way is to have a robust planning policy that keeps new housing developments out of flood plains. Another is natural flood management, such as planting trees, building “leaky dams” and water storage facilities. These all help slow the flow of water downstream and would take the edge off severe storms , said Prof Hannah Cloke, of the University of Reading. Prof Robert Wilby, of Loughborough University, said natural flood management would help mitigate small floods but would be overwhelmed by the likes of Ciara and Dennis.
Another important tool is forecasting: the Met Office’s new £1.2bn supercomputer could be a game-changer in predicting the areas most at risk of flooding. Experts say more energy should be devoted to contingency planning, local resilience measures and regular maintenance of flood defences and drainage systems.
Is money being spent in the right places?
The government says it invests in areas of the highest priority. Critics say this often means protecting urban areas or properties of high commercial value, at the expense of rural communities, farms and villages. One problem is the fluctuating amount of money set aside for flood prevention each year, which means agencies cannot plan too far ahead or invest in radical changes to the landscape. In early 2019, the Environment Agency said at least £1bn a year was needed to tackle flooding and coastal erosion – more than the £600m-£800m a year that has been spent since 2010.
Boris Johnson’s government has committed to spending £4bn on the issue over the next five years but experts argue that a more ambitious programme needs to be implemented, looking at a broader range of defence mechanisms. “Hard flood defences are just a tiny part of what we should be doing,” said Cloke. “There’s no realistic way we can manage future flooding with hard flood defences – we really need to be thinking more than that.”
Why are there so many floods?
The recent floods have been so widespread and damaging because the ground across Britain is saturated. It has been an exceptionally wet winter so far with autumn rainfall records being broken for South Yorkshire, Nottinghamshire and Lincolnshire. England as a whole had its fifth wettest autumn on record. Why? In large part, this is due to the climate emergency. Evidence from the Met Office shows the number of winter storms has increased in the north Atlantic and that they are getting stronger. Heavy rainfall events are also becoming more frequent: warmer air carries more moisture, which means rain falls in heavier showers.
