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We need more subtle flooding solutions than a national grid

Britain is once again facing winter flooding, the Environment Agency warned this morning. It’s hardly surprising given the ‘wettest summer in 100 years’ we were experiencing just a few months ago. At the time, however, many people were also dealing with the ridiculous contradiction of a drought and hosepipe ban when the heavens kept opening.

Climate change is likely to make floods and droughts much more common around the world. And given our general lack of experience - and therefore tolerance for extreme weather in Britain - this will probably become an increasingly important political topic over the coming decades.

Right now, however, there doesn’t seem to be an awful lot being done to prepare the country for the increased frequency of water problems: in fact, flood defence budgets are being cut. A draft water bill going through Parliament appears to focus largely on tinkering with the water market to bring bills down and encourage water companies to take less from the environment.

So what can be done about it? The most obvious idea, and one that perennially rears its head, is to create a national water grid to transport water around the country, generally from the soggy parts of Scotland, Wales and the north of England to the parched southeast. ‘The Romans did it, so why can’t we?’ proponents cry.

A recent report by consultancy Davis Langdon echoes the calls of London mayor Boris Johnson in arguing for a revival of the Grand Countour Canal plan of 1942, to build a canal linking the Scottish Borders with southeast England. Following the 310ft contour of the hills, the canal would be relatively economic, the report says, because it would require no locks or pumping to keep the water flowing.

In some ways it sounds appealing. We’re entering a new age of massive infrastructure building – HS2, new nuclear, new Forth bridge – and the case for government funded capital programmes to stimulate the economy has been bought even by many Conservative politicians. Plus the Olympics have proven that we can pull off big projects on time and on budget. An unscientific poll of Engineerreaders had almost two-thirds of you in favour of such a pipeline.

But take a look more closely at the idea and you’ll find it’s riddled with problems. Even using the gravity provided by the contours, this plan would still be massively and prohibitively expensive. Even the Davis Langdon document acknowledges Environment Agency findings that large-scale water transfers would cost four times as much as building new reservoirs to meet demand in the Southeast.

Using canals to move water around means you can’t use them for transport so any water network that integrated our existing canals would put an end to any of their other functions. Plus moving soft water to hard-water areas where the environment is based around different chemical compositions could be hugely damaging.

Boris Johnson’s response to this argument (in an article in the Telegraph): ‘This sounds pretty much like tripe to me… The chemical composition of water is H2O, and that is true across Britain.’ Perhaps we shouldn’t expect anything else from a politician who has become well known for his support of grand projects that fly in the face of evidence against them or are otherwise completely unnecessary.

But the deeper issue with this plan is that water imbalance in Britain isn’t as simple as the north has too much and the south has too little. Hosepipe bans can and have been put in place all over the country and parts of the Southeast suffered flooding this year. And we saw we can have drought and excessive rainfall at the same time in the same place. Putting in place an extensive national water grid that could pump water to and from all areas of the country would run up costs that aren’t even worth considering.

It’s no wonder that the government Environment Agency, the water industry and the Institution of Civil Engineers all oppose such a plan. But we’re still faced with the question of what can be done instead. The general consensus is that improved local water management and more water transfers across and between regions through short interconnections is the way forward.

But Jacob Tompkins, civil engineer and managing director of UK non-governmental organisation Waterwise, argues that we need to go further and institute a complete change of philosophy. ‘Engineering has moved on in the 2,000 years since the Romans,’ he says. ‘We need a modern solution to a 21st century problem.’

The answer, in his mind, is an integrated water management plan across the country that works with nature rather than fighting against it. This means focusing on small-scale storage rather than a few big reservoirs that empty and fill rapidly as the weather changes; allowing flooding to occur on farmland so we get less runoff into swollen rivers and more water into underground aquifers; and reducing demand using water meters and other water-saving incentives.

I’m not quite convinced that all these ideas would be as simple and effective as Tompkins seems to believe. True, it’s ridiculous that most people in the UK are still charged a flat rate for water usage. And improved water storage at a local level across the country appears sensible – our big reservoirs certainly don’t seem to be doing the job.

But I’m not sure whether most farmers would accept the inconsistency brought by allowing their land to flood, even if a sustainable way to compensate them could be found. And if we were to do this, it would require the dismantling of existing flood defences, a costly exercise that I think would be greeted with much unease by the public.

However, Tompkins is right that the dramatic change in climate and the effects that will have on the UK’s water supply require a change in thinking. Difficult problems require subtle solutions and a giant infrastructure project won’t necessarily provide that. But whatever we decide, the work needs to start now if we want to avoid the huge financial and personal costs of yearly floods and droughts.

Readers' comments (27)

  • Flooding does not look like going any time soon, in fact with so called global warming it is likely to get worse.
    Why do we not change our building policy particularly in flood plain areas to build houses on raised pillars, with perhaps integral garage on lower level. If the garage floods it is likely to cause minimal damage, but it will allow water to pass by the raised living accomodation?
    This would take some time to achieve, but all new builds should be done like this.

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  • An infrastructure of land level pipework from low lying flood areas with pumping systems to literally pump water from a receptor sump in the low lying plane to reservoirs elsewhere in the country that are devoid of sufficient water. In this way, depending upon weather conditions, water can be literally moved from flood areas to other areas requiring water to prevent damage to buildings, and farmland.

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  • A lot of the flooding is the lack of maintenance carried out in this country. Years ago before road transport, rivers where kept clear so heavy loads could be transported. Streams and ditches flowing into rivers where always cleared out before the onset of winter. Surely if more water management was carried we could see more use made of the rivers to generate electricity using turbines.

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  • We could use windmills to pump the water from one storage area to another - they're rather better suited to that than generating electicity.

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  • Over here in the Netherlands we live below sea level in the most part of the country. Plus we are getting all the water from the big rivers from Germany and France. We have learned that mirco-managing surface water really pays off.
    Regulating water levels in ponds and even ditched is fairly simple and low maintenance. Adding it all up results in a HUGE volume which can be stored for puping out later. Does not mean it always works OK but it does most of the time.
    I do not worry about living 6 meters below sealevel....
    In the end it all comes down to the cost of the infrastructure but I bet it will be quite a fraction of the proposed North to South water canal. Plus it would ruin your beautiful counrtyside.

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  • "Using canals to move water around means you can’t use them for transport"

    Utter Codswallop!

    Pownall's Grand Contour Canal was designed to be both a navigation and a water supply. Based on the 310ft contour but set at a very shallow gradient that would ensure a steady flow of water from north to south, but it would present no problem for freight movements.

    "Plus moving soft water to hard-water areas where the environment is based around different chemical compositions could be hugely damaging."

    If you are simply going to regurgitate Waterwise's assertions then you might as well include their claim that "Also your cup [of] tea would taste funny!"

    Boris may well come out with daft ideas, but when it comes to the Grand Contour Canal his grasp of engineering and science is somewhat superior to yours.

    You state that both the Environment Agency and the Institution of Civil Engineers oppose such a plan. Do you have any evidence to support those assertions or are you simply repeating Waterwise without checking facts.

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  • Quote from ICE water panel chair Michael Norton:

    “A national water grid is not only impractical both economically and environmentally but also in reality is a major undertaking - it couldn’t be done anytime in the near future, and between now and then the problem would only worsen. You can’t compare it to the national electricity grid; water is a heavy incompressible liquid which requires huge quantities of carbon-based energy to move it."

    From the Environment Agency's report on large-scale water transfer:

    "We conclude that there is no new evidence of a need for large-scale transfers of water to south east England from the north of England or from Wales."

    Also see this document from Water UK, the water industry's trade body:

    Your point that the Grand Contour Canal would move water very slowly is valid but rather highlights another problem with the idea in that it would not provide the flexible solution we need.

  • A number of issues here:
    1. Fun as he is, you are right to disparage Boris for his ignorance of differing water properties between regional sources, but it is a common misunderstanding.
    2. It is probably easier (cheaper) to balance the quality of imported soft water by a mineralisation process than the other way round, so that is not a show-stopper, but it is a contributing expense on the “down side”.
    3. Having carried out mineralisation, we would have the added nonsense of domestic softening still being taken up!
    4. Even so, the taste of the water would be different and customer reaction would be another significant consideration. Given varying availability, there would probably cease to be any “standard” water in the deficit-compensated regions.
    5. On the engineering front, contours tend to be too level to induce flow. I have done some pretty complex sums and discover that an Aqueduct following the 310 ft contour (may we say 100 m, as we are no longer Romans, nor even Victorian?) would need an infinite diameter in order to pass (say) 1000 Ml/d with zero headloss, since gravity is to be the driving force.
    6. Not sure why you say the present uses of existing canals would be lost if they were used for water transfer – they already do it by capturing water from local rivers and using it on a different profile, so that the rivers are a pale shadow of their pre-navigation selves. But as they have a limited hydraulic size, their slight gradient is not enough to handle significant quantities of water, so the implication more-or-less stands.
    The conclusion that mega projects are not the answer also seems to be correct, and maybe a host of mini projects is a big part of the answer. For instance, grey water capture so that we all used rain water butts to supply our loo flushing, car washing and (big gardens can have big water butts) lawn watering, then we may start making a difference on a useful scale.
    One of the biggest, though, is to balance agriculture to the new reality. To my mind it has always been an absurdity to grow water hungry crops in vast tracks of our drier regions, depleting the ground water by irrigation: much better to grow cereals on our flat lands while letting the emergent economies, where we have created the economic dependency on sugar cane, make an honest living by supplying our sugar, and stopping growing corn on our hillsides where all the topsoil is now washing away.

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  • I salute Jacob Tompkins for his insights into seeing the solution for the present poor catchment management strategies. Although such things still fly in the face of the mega corporate agendas, small has always and will always be beautiful and water retained within our agricultural landscapes can easily provide a multifaceted solution to a number of problems.
    Poor Boris, was educated after all, not in the living sciences and will undoubtedly know next to nothing of the unique and special qualities that water has in its intrinsic links to the soil and geologies with which it comes into contact with.
    This year has seen the highest levels of precipitation since records began in 1853. I appreciate that this may be a little far fetched for many readers here, but this change has been caused through the initiation of geo-engineering our atmosphere, technologies that for those prepared to look at patents and research being undertaken, is provably occurring.
    As a specialist in aquatic ecologies and hydrology, I can assure the readers that as a resource, small scale (farm) reservoirs provide a wealth of potential for evolving a number of technologies, some of which date back to pre Roman times, but which can provide energy, nutrient buffering, ecological enhancement, biomass (high protein) for fodder and fuel, topsoil regeneration as well as water for domestic use.
    Many authors and innovators have established technologies that are both well established in practical terms and proven to yield multiple resources.
    In Germany, housing is not permitted unless harvesting rainwater is not included. Why not extend this as an initiative for our parks, farms and urban areas.
    As one example, I would recommend reading "Water for Every Farm@ by P A Yeomans.

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  • Design:
    Flood evacuation system

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  • I recall that in thge early 1960's the Institute of Civil Engineers proposed that large pipe line systems to transfer water through the country should be incorporated into the motorway building programme. It was rejected by Government on the grounds of cost.

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