The recent flooding can help improve our flood defences

Professor Dragan Savic FREng is the co-director of the Centre for Water Systems, and Professor of Hydroinformatics at the University of Exeter; here he discusses what important questions have arisen from the recent flooding.

The dramatic events that have consumed the South West in recent weeks offer perhaps the greatest understanding of how devastating flooding can be to people and communities. However, with conditions continuing to deteriorate across the country, now is not the time for apportioning blame.

Instead, the main focus at this time should rightly be on helping those affected and on protecting lives and livelihoods. Yet this current, extensive flooding should also raise a number of serious questions in us all, both as individuals and members of a wider society.

The first question we should ask, perhaps, is why we cannot seem to provide total flood prevention. After all, we do not face the frequent and devastating monsoons and widespread flooding that affect many developing countries in South East Asia, for example, while our continental neighbours in the Netherlands seem to offer tangible evidence as to how hard engineering can provide ‘total flood control’, by forcing back and so keeping out the river and sea waters.

However, the Dutch are well aware of the difficulties associated with building ever-larger flood defences to combat changing conditions that may be the result of global warming. Instead, they have instigated a policy of ‘managed retreat’ from some coastal areas. This doesn’t mean they have stopped upgrading, rebuilding and improving existing flood defences, but are instead developing a portfolio of measures to manage floods and live with flooding.

So perhaps we need to start recognising flooding as another type of risk that we live with and manage in our daily life. With flooding, we have to accept that there will always be a real risk and that it cannot be completely eliminated. Even the huge investment in improving the UK flood defences after the tidal surge of 1953 could not completely prevent the flooding experienced in the recent storm surge event last Christmas.

Yet there is no doubt that risk has been reduced in recent years. If you compared the flooding of 1953 and now, which are comparable in tidal height and the strength of the wind, then the previous flooding caused much more devastation – causing 300 deaths and numerous sea wall breaches.

This and other recent major flooding incidents, such as those experienced in Gloucestershire in 2007, Cumbria in 2009 and Wales in 2012 would’ve caused much more damage if it were not for the work and expertise of the Environment Agency that has been given a clear overview role in managing flood risk.

The way forward is to forget about one simple ‘silver bullet’ solution to the flood risk problem, such as dredging or only building concrete floodwalls, but to think of flood risk management as a way of increasing societal resilience.

This would involve a combination of measures and decisions: to prevent or mitigate flood risk, to prepare for inevitable occurrence of flooding, to develop warning and alarm raising systems, to plan for an effective response to flooding events and limit loss and exposure, and to plan and organise recovery.

Even if we focus only on prevention and mitigation of flood risk, the difficult decisions will have to be made by Government, its agencies, local authorities, families and us, individuals.

We have to ask ourselves some tough questions. What are our strategic priorities, for example in large populated areas? Can we develop more synergistic policies that help reduce flood risk, like encouraging better farm management practices? Where best to invest limited funds, to gain maximum protection from flooding? Can we allow some farm land to be designated for being safely flooded in extreme situations to protect towns elsewhere? Can we continue to build on floodplains? When do we consider managed retreat from flood vulnerable areas?

The bottom line is that flood management is not only about how much dredging we can do, how many more new drains to dig, or how much concrete we can pour. We have to use our best science and engineering, but also work with nature to maximise natural flood protection, which means: protecting and restoring wetlands (that can store or slow down water flowing into our rivers), reconnecting floodplains (to make space for water and protect important areas), investing in upland forestry (to reduce flooding downstream), etc.

For example, research at the University of Exeter has demonstrated that restoration of peat bogs on Exmoor could result in a third less water leaving the moorland during heavy rainfall compared with previous years.

Growing populations, increasing urbanisation, economic growth and climate change mean that the likelihood and the consequences of flooding are likely to increase. The question we face as a society is not whether we can beat the nature, but whether we can live with it.

To achieve the above, public bodies, businesses, communities, families and individuals will all need to prepare to do their bit to respond to the threat of floods and to learn to live with them. This year marks the centenary of the beginning of the First World War, but this time the urgent recruiting slogan could be “Your country needs you to prepare for and live with floods!

 

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