Holding back the tide on flooding

The imminent arrival of winter means a renewed deluge of political interest in flooding. For the few days or weeks when these extreme weather events occur, they inevitably dominate the national media. But, as the waters recede, so does the political interest in the subject. As a result, it can be difficult for policy-makers to sustain the momentum required to introduce policies to tackle the problem.

The risks and potential harm from flooding are significant. As well as damaging businesses, homes and infrastructure, it can endanger human life. Take the example of last year’s floods: The Association of British Insurers estimated their members would pay out around £1.3 billion in flood-related claims. The Local Government Association estimated councils faced £250 million of damage to local infrastructure. Storm Desmond, the weather system that caused the flooding, also claimed three lives.

Nor was this a one-off: academics have found that this kind of flooding event is being made 40% more likely by climate change. A warmer climate enables the air to hold more moisture, which increases the likelihood of flooding. Flooding is already a major environmental challenge, and is going to get worse as average temperatures continue to rise.

Forecasts of the future impact of flooding are stark. In its last Climate Change Risk Assessment in 2012, the Government forecast that the average annual cost of coastal and flooding damage will rise from around £1.3 billion now to as much as £6.8 billion by 2050. In its report this summer, the Committee on Climate Change modelled a scenario where average temperatures rise by 4°C. In that case, they predict that the number of at-risk households would rise from 860,000 today to 1.9 million by the 2050s.

Land management

One strategy to reduce flooding damage is to slow water flow from the uplands where rivers form to lowlands where population centres are. These upland floodplains can in effect store excessive rain water.

There is academic evidence to suggest planting more trees further up a river’s catchment area can help to slow flow rates of water. Rewilding Britain recently called for tree planting in areas where overgrazing has denuded landscapes of natural forest cover in order to assist flood management.

Dredging of rivers is similarly important to upland catchment management. In 2013, the Environment Agency published a review of the academic literature on dredging, which found no clear evidence that lower water levels from dredging led to reduced flood risk. On the other hand, they did find good evidence that dredging increased water flow rates, increasing flood risk downstream. This evidence was disputed by some commentators in the aftermath of the Somerset floods in 2014.

The Government’s National Flood Resilience Review, launched after last winter’s flooding, tested how well the UK’s infrastructure would cope with a 20-30% uplift in extreme floods across the UK, relative to last winter. As well as ordering key assets to be reinforced, the report highlighted the importance of the 25-year plan for the environment, due next year, in the context of flood risk management. The plan will enable a ‘whole river catchment’ approach to be adopted.

Other policy responses

In the aftermath of flooding events, debate often centres around levels of public spending for flood defences. Last year, there was a disagreement between the Government and the Opposition over whether there had been cuts or not. Comparing the spending envelope for the whole 2005 parliament and the 2010 parliament, there was a real-terms increase from £3.1 billion to £3.4 billion. However, the spending wasn’t evenly distributed over the parliament, with some years seeing a spending reduction relative to previous years.

The Environmental Audit Committee’s recent report criticised these big fluctuations in spending within a parliament and the often reactionary nature of those decisions. Dieter Helm has called for funding to come from a flood levy on water bills or council tax. He argues this would depoliticise the issue, facilitate a ‘whole river catchment’ approach, and create a more stable revenue stream to fund investment in flood defences.

There have also been calls to change the National Planning Policy Framework to prevent unnecessary building on flood plains. This was one of the Environment, Food and Rural Affairs select committee’s recommendations in the last parliament. Despite being in the 2010-15 Coalition Agreement, this policy was not implemented. Now, with the supply of housing so constricted, further limits on housebuilding would be politically difficult, and risk undermining one of the Government’s other key policy objectives.


Flooding has major economic and environmental costs, which policy-makers should seek to mitigate. But flood risk management also presents opportunities. There are potential actions that both strengthen flood defences and improve the natural environment.

It is likely following the EU referendum that the UK will withdraw from the Common Agricultural Policy. Former Environment Minister Richard Benyon MP has suggested using a portion of this funding to pay farmers to hold back water. This could involve planting trees on their land or using fields as flood plains. Such an approach is worth serious consideration, and could deliver benefits for flood mitigation and the environment simultaneously.

Sam Hall is a researcher at Bright Blue