Flood Defences: Getting our Priorities Right

Written By: European Sales Director, Hydro International

When the cuts start to bite, what’s the best way to spend limited flood defence funding? It’s a debate that’s crystallising priorities amongst policymakers, politicians and affected communities. Not always for the better – and just as the prospect of another wet winter is looming.

On December 2, the Government published details of how£2.3billion of capital investment already committed for flood defence funding will be spent on more than 1,400 flood defence schemes to protect 300,000 homes as part of the National Infrastructure Plan (View the full story).

But the Government’s own spending watchdog, the National Audit Office, published a report Strategic Flood Risk Management on November 5, which highlighted that there was a 10% funding decrease in real terms for capital and maintenance projects during this parliament, despite the extra money made available following last winter’s storms.  That’s making it more and more difficult to maintain current flood defences.  The pressures inevitably mean channelling money to build and maintain higher risk defences, leaving lower-risk defences (about half the total) that have a less favourable benefit-cost ratio, to be maintained to the bare minimum.

The Government has also revealed its intentions to slash local authority flood defence budgets by a third in 2015-6, according to a policy paper released on 4 November 2014 and its intentions for SuDS implementation and adoption have already been significantly watered down.

This put me in mind of two thought-provoking press stories I read recently: the first by Jonathan Leake in the Sunday Times points to a ‘secret’ maintenance report handed to Liz Truss by the Environment Agency and compiled following consultation with internal drainage boards. It highlights the consequence of Government policy in which money for river dredging can be justified only if there is an average of £8 benefit for every £1 spent. The effect, the story suggests, is to focus spending on urban areas, whilst rural and agricultural land does not qualify. As a result, rivers flow fast through dredged urban sections, whilst in rural parts of the catchment they are left to block and flood.

Meanwhile Infrastructure Intelligence, the website of the Association for Consultancy and Engineering, published an article debating the pros and cons of capex and opex spending: Should limited funds be spent on permanent defences with higher upfront costs or temporary demountable solutions downstream?

The article suggests that the hierarchy of choice preferred by the Environment Agency and other flood authorities is firstly to have fixed or passive defences which work automatically in a peak flood situation, with active defences like barriers and pumping stations a second choice, and temporary defences requiring manpower and transport to erect, last.

Passive defences – likely to be upstream attenuation schemes – may require a greater capital outlay, but the costs can be justified in lower maintenance, energy and amenity value over a very long operating life. One such solution, using Hydro-Brake® Flood Alleviation flow controls has been proven on a number of schemes including the award-winning White Cart scheme in Glasgow. The latest flood defence scheme at Northallerton, in North Yorkshire, is currently nearing completion.

So, It’s all about priorities:   For me, the best priorities are founded on the ‘back to the basics’ of sustainable surface water management: Whether at a catchment or a local level, source control and upstream attenuation at peak flows is the most effective and sustainable solution. That means looking at a whole river catchment first and protecting downstream urban areas with passive, upstream defences. Meanwhile, in the urban areas, SuDS principles of mimicking natural surface water paths and processes should still apply, using the best combination of components from the SuDS Toolbox.

As these current debates show, harsh cuts in funding mean tough decisions: But let’s not make the wrong ones. Short-term and localised answers to flooding could merely move the water onto someone else’s patch, or put off a solution for the next generation, whilst communities endure flooding risk. A holistic approach based on sound catchment management approaches, and integrated, water-sensitive philosophies has to be the starting point.

View National Audit Office Report: Strategic Flood Risk Management

View Defra Report: Reducing the risks of flooding and coastal erosion: an investment plan 2041.  Published December 2 2014

 

 

 

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