Expert comment: UK flood preparedness

Professor Hannah Cloke, Professor of Hydrology at the University of Reading, comments on the Public Accounts Committee's report on the UK's flood preparedness. 

"This report from the Public Accounts Committee provides some useful insight into investment in flood defences. It highlights some problems that are well known by flood scientists, namely that flood defences can be very expensive and complex projects that require maintenance.

"Regular investment of public money into flood prevention schemes is needed to protect homes and vital infrastructure. I believe we need to take longer-term investment decisions, rather than relying on funding announcements from politicians covering only a few years.

"New homes are being built in flood prone areas all the time, which is something we should really avoid. The Environment Agency does a pretty good job of providing advice and raising objections to plans for homes where there is an unreasonably high flood risk.

"We have to realise that almost any home can be flooded. Flood defences work best where the risk of flooding is properly modelled and understood, and residential areas are designed to flood in a way that does the least damage to the things we want to stay dry, like homes and buildings, and keeping services operational like roads and electricity lines.

"While we should avoid putting people in harm’s way wherever possible, it is possible to build homes in flood prone areas. There is a good reason why people want to build houses and live on flat, wide areas of land close to rivers, for example. Rivers can be beautiful neighbours, but they can turn into rampaging monsters in a few hours. To avoid the worst impactsin years, decades and generations ahead,flood resilience needs to be designed into developmentsfrom the start. Keep homes away from areas that flood where possible, and build them so that their occupants can recover quickly after flooding if it does happen."

Climate change impacts

"Floods are getting more common and more severe in the UK as the climate warms. This is partly due to the intensity of rainfall increasing, due to the principle that warmer air holds more water. This either dumps a lot of water into river catchments which flood more quickly, or causes direct surface water flooding as the intensity of persistent rainfall turns roads into rivers and water runs directly off into places that aren’t expecting it.

"A major risk from climate change comes from rising sea levels, which are steadily creeping up year after year, and will continue to rise for centuries, even if we successfully reduce emissions in the next few decades. This increases the risk that storm surges will overtop coastal defences, or combine with high rivers and surface water floods to create compound floods at the coast."

Resources to avoid floods

"The Environment Agencyneeds to bewell resourcedfor the long-term, and thegovernment’s£5 billionplan announced in 2020has helped to speed upthe creation ofnew flood defences in recent years. But there is no level of resourcing for flood defences that would mean every home in England, or every piece of farmland was protected from being flooded.

"I believe we need to overhaul the planning system to factor in the impact of development over a larger area. Through piecemeal decision-making, we have concreted over an increasing proportion of land. This means as a whole, rivers respond faster to heavy rain as the water runs off and goes straight down the drain, increasing flood risks elsewhere."

Flood early warning systems

"As a flood modeller, I think more investment is needed in flood early warning systems. Too often, the damage is done to people’s homes or businesses by people failing to respond quick enough to the risk of flooding. In the recent floods after Storm Henk, people’s houses were letting in water hours before flood alerts were issued, or people don’t know that an alert has been issued, perhaps because it was happening overnight.

"This requires greater investment in every part of the early warning systems, involving better communication, improved flood forecast models, using more real-time data, and using sophisticated ensemble forecasts. This should mean the Environment Agency could provide better advance flood alerts for individual areas in advance, as well as providing general advice across a wider area.

"Flood forecasts in the UK are better than ever before, but could improve further."