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MP’s focus on dredging and defences will not prevent floods

The record rainfall and persistent storms of winter 2013-14 caused serious flooding throughout the southwest of England, with breached defences, loss and damage to agricultural land, homes and businesses…

This can, and will, happen again. Steve Parsons/PA

The record rainfall and persistent storms of winter 2013-14 caused serious flooding throughout the southwest of England, with breached defences, loss and damage to agricultural land, homes and businesses. A report by Deloitte as the waters receded in April put the cost at £1 billion pounds. Now a parliamentary select committee of MPs has published its report with recommendations for the way flood defence and drainage is funded and managed – many long overdue.

The Environment, Food and Rural Affairs Select Committee argues that funds to maintain flood defences are inadequate, calling for a single fund that would allow flexibility between capital and revenue expenditure in any year for this vital area.

The committee also recommend Defra give the impact of flooding of agricultural land higher priority, awarding what some would see as greater and overdue recognition to the social and economic aspects of the rural farmland areas. While extra funding has come from the government to protect and recovery flooded farmland, this is mostly money reallocated from other programmes in fairly opaque ways.

There are also demands for clarification of the responsibilities for maintenance and dredging of channels shared by landowners, the local Internal Drainage Boards, and the Environment Agency. Pilot schemes to give more responsibilities for channel maintenance to local landowners should be extended, with funding provided for channel maintenance by the drainage boards to be retained so that it can be handled locally.

The committee is unequivocal about the need to prevent any further losses to frontline staff. At the time of the floods, the Environment Agency was in the process of shedding many hundreds of staff due to government funding cuts. The floods caused a rapid review of this plan, with frontline flood management posts to be retained – at least for this financial year. The committee’s calls for “reassurances” from Defra are backed up by stating that, regardless of budget constraints “the avoidance of flood events that devastate communities should, as far as is possible, take priority over cost-cutting”.

Dredging returns as a cure-all

It is clear that the committee has particular sympathies with those rural communities affected by the floods, and sees channel dredging as a way of preventing the most devastating effects of flooding. The committee understands this is not a solution that will be useful everywhere, but they recommend that local land owners and drainage boards are allowed to keep channels clear by dredging.

But as part of its role, the Environment Agency is required to assess the benefits of capital investment and maintenance of flood defences, prioritising that which provides the greatest protection for the least money. As I have noted before, total flood defence is a myth: floods happen and will continue to happen and areas at risk cannot be defended in all cases. And so some spending prioritisation is required.

This raises the issue as to how far society as a whole should be responsible for protecting those who choose to live or base their businesses in flood risk areas. It’s understood that the existence of flood defences tends to promote further development in areas already at risk. This is not only an urban phenomenon – farmers in the Somerset Levels lost livestock and winter crops sown in land flooded because the defences were overtopped, land it was only possible to use because of the defences. But dredging the channels there will perhaps cost more than the value of what was lost, even if for the people concerned the impact is just as devastating. This is one reason why there will always be a preference towards protecting more built-up areas, because the benefits of investment in flood defence will be greater.

Not only can we not repel every flood, it’s even been suggested recently that the national benefit from flood protection, in terms of savings due to damage avoided, might have been overestimated. But there have been benefits. Only 7,000 properties and businesses were affected by flooding last winter, while 1.3m were protected, compared to the 55,000 properties flooded during the 2007 floods. While the two events are not directly comparable, there were communities on some major rivers such as Bewdley on the River Severn that were flooded in 2007 but protected last winter due to investment in defences, permanent or otherwise.

Unintended consequences

On the other hand, some communities might have experienced flooding aggravated by flood defences elsewhere. The people in Wraysbury and Dachet on the River Thames, for example, feel flooding there was made worse last winter by the Jubilee River, designed to divert water away from Windsor, Eton and Maidenhead and built at a cost of £84m.

This is just one example of why flood risk management in a river basin needs to be integrated, not considered only on a local basis. Otherwise excluding water from some areas upstream will increase the risk of areas downstream. The same applies to dredging.

Dredging tidal rivers, including parts of the channels in the Somerset Levels, should be done with particular care. Greater channel capacity will, in that case, also allow the high tides to move further upstream and back up more of the water that is being expelled down the rivers. Where a discharge peak coincides with a extreme high tide, this could increase the risk of overtopping embankments.

Dredging will also have a significant impact on the river ecology. The Environment Agency has a responsibility under the 2003 Water Environment Regulations to improve all rivers towards a healthy ecological status – a requirement that may well conflict with dredging a channel.

The select committee’s report says nothing about such conflicting requirements, nor how they should affect investment by society as a whole. It has nothing to say about assessing cost-benefits of such investments. It has nothing to say about integrated management, preferring local management instead. And it says nothing about taking steps to prevent further development on flood plains, focusing only on improving and maintaining defences. It seems there are more lessons to be learned from the winter floods of 2013-2104 than the committee have recognised in this report.