Floods – the answers in the land

Looking at vast areas of the country flooded yet again made me think about what we can do. Some of the answers are in the land.

Flooded Village

Flooding costs the UK around £2.2 billion a year.

Whatever we do, these extreme weather events are going to carry on. The ‘once in a hundred years’ rainfall that seems to come every few years now. We really need to do a lot more to protect ourselves and handle these events.

There’s no one solution, but rather a number of things we can do. Civil engineering works have their place but they’re expensive. Putting flood walls by rivers will give towns some protection but the cost is, rightly in my opinion, balanced against the benefits. How many houses will a scheme protect for the cost, being the question. This at least gets the best value for the money we as a society spend.

Green Engineering – Soil

Green engineering can offer even greater benefits but it takes time and isn’t always obvious. The first line of defence is the soil. It’s proven fact that humus-rich soil absorbs water. Clay, with its very fine particles and small pore spaces often repels water. Little can penetrate the surface and percolate down. Sandy soils with large particle size and pore spaces let water in easily but it washes through very quickly.

So the water gets quickly to the river which floods. By adding the magical humus and organic matter, clay particles aggregate into larger particles and both soils absorb and hold water like a sponge, releasing it at a rate the rivers can cope with. The deeper the top soil, the more it can hold.

Conventional farming has treated the soil badly. It’s been thought of as some sort of material to hold fertilisers for crops. Compacted by heavy machinery, those pores are closed and effectively it becomes a clay like soil.

There are farming methods that actually improve the soil, regenerative farming. Farmers are very conservative – they take a lot of persuading to jump on bandwagons and change. They think in long timescales, decades rather than months.

The government should fund research into these methods – proving them and finding the best practice. The cost of that would probably be a tenth of a modest flood defence scheme. Then give the farmers that information – they’re not fools, if they see a real benefit they’ll adopt the practices.

Don’t forget, properly managed grass land on deep top soil will absorb huge quantities of carbon as well, reducing CO2 in the atmosphere. Striking at the cause of climate change as well as coping with its results.

Green Engineering – Trees

Next we have trees. I’m not talking about replanting forests but bands of trees, planted where they’ll do the most good. They too absorb carbon and hold it but they also bind and stabilise soils. Creating more humus from their shed leaves and shielding from storm winds. When rain soaks the land, the trees drink it in as well. This helps to reduce the problem further.

Green Engineering – Swales

Swale Diagram

A swale captures water allowing it to better infiltrate the soil and slowing run-off

There are landscaping solutions than can help – although civil engineering and green engineering are blurring together here.

Swales are a water control system used in permaculture – often to make use of scare water in dry climates. Basically wide ditches that follow the contours of the land so they fill with water in rainy weather. Unlike ditches that usually drain into a stream, swales are level and the water slowly filters out into the soil on the the downhill side.

Often swales are edged with trees on the downhill side, with the same benefits from the trees as referred to above. They can also be built on a small scale. On a small scale they can be combined with French drains and ditches to provide localised protection.

Slowing Not Stopping Water

Improved topsoil, tree bands and swales will not stop water running off in an extreme rainstorm but they will slow down the run off. If, as happens, a month’s rain falls in a day the rivers swell with 30 days influx. If that run-off can be spread over 5 days, the problem is only a sixth as bad. Even if it only spreads the problem over two days, halving the problem can possibly avoid the catastrophic floods.

Further actions to help with floods.

Another green / civil engineering solution is to create storage ponds. Farmers often face two problems – lack of water and too much water. Building storage ponds on the land helps solve both problems. Of course they take some growing land out of production but drought and flood can take the whole crop – effectively all the land.

These ponds can be decorative, natural ecologies in themselves. Enhancing the landscape and eco-system whilst providing emergency water storage and supply for the farm land in drought.

All the answers?

I don’t pretend to have all the answers but it’s obvious we have to put more thought and energy into the problems coming with climate change and extreme weather. These green solutions are not free but they are cheaper than many of the hard engineering solutions being made.

Money – Loads of Money

River Flooding Drowning Cars

River bursting its banks causes catastrophic damage and endangers life

According to the UK government

Flooding, and managing it, cost the UK around £2.2 billion each year: we currently spend around £800 million per annum on flood and coastal defences; and, even with the present flood defences, we experience an average of £1,400 million of damage. While the level of spending is fairly steady, damage due to flooding is intermittent and can be huge when a major flood occurs.

Full report Foresight Future Flooding

Spending more now – and remember we’re talking hundreds of millions – will save for more in the future, help with climate change and improve the environment for us all.

Posted in Allotment Garden Diary
15 comments on “Floods – the answers in the land
  1. gwyn evans says:

    I think the rivers should be kept clear of rubbish and dredged on a regular basis during the summer when water levels are low and access with machinery is possible,Eg if your gutters on your house was full of leaves you would clean them in just the same way to prevent water flowing over the sides, Every year when we have flooding it usually happens in the initial heavy flow of water causing trees and other rubbish to wash downstream and cause the problem, once the initial heavy flow has happened the risk of more flooding gets less, as a lot of the rubbish was washed down stream, I remember in the 1960s farmers would use gravel from rivers on the farms in concrete or filling potholes it was a cheap and useful way to use it up and keeping the rivers clear, I don’t think you could do it now due to messing up the environment and destroying wildlife in the streams.

    • John Harrison says:

      You’re right gwyn but important to do the whole river or the problem is just shunted downstream.

      • gwyn evans says:

        Yea I know you might have to clear a lot of rubbish initially but cost would come down for insurance and damage to property in time, You would also need to do less clearance some years, you only have to see some of the footage on the telly, you can see saplings and grasses growing on the side of some streams, there needs to be a lot more joined up thinking at the Environment agency.

      • tj says:

        It has been said that the habit of trying to get water to the sea as quickly as possible was the reason for fish stock depletion in rivers and, perhaps not oddly, straightening all the rivers and directing them through concrete channels has hugely affected the likelihood of flooding – what you need are wide slow rivers with sufficient flood planes. As for farmers, they are a product of the state, if they don’t tow the official line (introduced during the war and exacerbated by the EU) they just haven’t survived, luckily there are some very brave farmers/business men that buck the trend, they need our support not our condemnation!
        Lovely to hear (and be part of) a lively discussion on an important topic

  2. Rowland Wells says:

    Something comes to mind about closing the door after the horse has bolted!

    The exceptional heavy rain this autumn has caused major flooding and it’s not so long ago that we where mopping up the villages and towns of Somerset and now its the north of the country that has sadly meant devastation for many people

    We know more has to be done to overcome flooding though there is no cheap option to doing so. I don’t agree with the blame culture levelled against modern farming methods on one hand we are asking the farmers to grow more cereal crops removing hedges to accommodate more heavy machinery draining the fields to run the water into ditches and streams of the fields

    There was no problem with that when we had the normal rainfall but when it rained for days and the levels of water went through the roof pushing the water into the ditches and streams putting more pressure on the already full rivers that unfortunately couldn’t cope and subsequently burst there banks flooding all In its way.

    I think this year is the only year I have seen many fields under water that have never flooded in my lifetime and those fields that have been sown the crop has just washed away leaving many fields not been cultivated and won’t be till spring

    Also there may be a case for more tree planting on farmland and I know many farmers round here have planted many trees through the government schemes but sadly there are less and less grassland or pasture land in this part of the country again its all down to supply and demand of cereal growing.

    I have to hold my hands up and say I don’t really know the answer to this inclement weather. Should it continue year on year, I think it could cost the country and many people many millions of pound to rectify the flooding problem.

  3. Des says:

    OK but . . . .

    Where do you start and where do you stop?

    Do you treat the cause or the symptom?

    Why do we get so much rain in the first place? Is it global warming that is disrupting weather patterns and increasing rain in some countries and leaving constant drought in others? Some “experts” still say that there is no global warming – it is just a “normal” fluctuation in global atmospheric conditions. It is a “blip” that will smooth itself out in a year or two and we will all wonder why we were so worried. Personally I think there is a cumulative impact and we are seeing the early stages of that in the freak weather patterns – but then again I am just a bloke who is an expert in nothing.

    So after years of discussion and negotiation we globally adopt environmental laws like the UN Framework agreement on climate change, and introduce controls. Well that’s the first problem, we don’t all introduce controls. From what I have seen some nations spend the money to implement controls and so increase the price of their goods. Others – like China say it’s a good idea, then studiously ignore it, go full throttle for maximum production and maximum exports and profit – belching out pollutants without a care. But it isn’t just them, I am sure I read somewhere that USA and Canada have still not formally ratified or adopted the latest climate controls, and probably never will.

    OK let’s just accept that something is causing lots of rain to fall, but why is it so noticeable? Have you seen complaints that some local authorities are opening flood gates and concreting river banks to protect their little town, ignoring the massive increase in floor water they send downstream? Near here they spent millions laying millions of tons of concrete to deliver a “flood relief scheme”. Where does that diverted water go? Was that expenditure rally effective in the grand scheme of things?

    Is it all them? No. Local authorities are building and giving building approval to national building companies to build huge new housing estates on flood plains. It aint rocket science guys, they are called flood plains because they sometimes flood in bad weather! Worse, concreting all that flat land – diverts billions more gallons of water downstream to create floods elsewhere.

    Remember the summer, and the last few summers. The moment the temperature hits 30 degrees, the water companies slap on a hosepipe ban (my poor allotment), and declare drought conditions. Then a month later we are trying to divert as much flood water as we can to run off into the sea to get rid of the “problem”.

    Isn’t national hydrology too complicated for us to “tweak” and expect nothing to go wrong? What would be cheaper, to A) leave those flood plains to do their job, accept that a field here or there will be soggy for a few days, leave grassland and trees and scrub land to absorb water as it is meant to, allow it to sink in and replenish the aquifers, or B) keep throwing concrete at the country and hope we can stop the water – and spending millions to mop up and repair all the subsequent flood damage?

    I agree Gwyn, stop the rivers silting up and filling with weed and rubbish. Plant more trees, leave the grasslands alone, slow the run off to stop that surge of water that makes a flood, when slowing it give the water a chance to sink in and top up the groundwater. Go back to basics.

    Signed – a bloke who isn’t an expert in anything – but does have a tidy shed.

    (My grandfather used to say you can trust a man who has a tidy shed)

    What’s that Mr Prime Minister – you want me to solve a few more global problems – OK but not this weekend I am still winterising my allotment!

    • John Harrison says:

      I don’t believe we in the UK can stop climate change on our own. That doesn’t mean we shouldn’t do anything, we’ve a moral duty if nothing else – even if it costs money.
      However, given it’s going to carry on and get worse, we need to do all we can to mitigate it.
      Building on flood plains is crackers – but it’s not just housing. I was looking at a photo of potatoes floating to the surface of flooded field.

    • tj says:

      Hmmm, if I look at the label on most of the products in UK shops these days (from pants to pans) they invariably say “made in china” so we are fuelling “China’s industrial output” so we can’t hang all the blame (if there is blame to apportion) on china.
      As far as flood planes being built on, well, we (supposedly) as a nation agreed to import millions of people who need housing, they will grow our population exponentially (to think in the eighteens we had such an opportunity, falling population, higher standard of living, a sufficiency of land all ruined now) and less money than ever before to put any of this right, “essential services” is what the what little we have will be spent on (that means mainly health care or the population squeels). With less land than ever before being used for farming or properly being put aside (people prefer manicured (sprayed) scenery to nature friendly tatty scrubland the future looks bleak for the UK, which will soon look a lot like Hong Kong, you gotta laugh

  4. MikeW says:

    Perhaps an answer to all the flooding is to get rid of the water out to sea where possible. In the 80s we built the CHUNNEL..a massive civil engineering project. How about much smaller projects, build a reservoir at the main confluence of the flood waters and bore a tunnel out to the cliffs. I’m no expert in this sort of thing but I’d say a metre diameter tunnel would take a massive ammount of water away. Huge cost? No idea…but we seem to be happy to spend possibly £100 billion on HS2!

  5. tj says:

    The water needs to get to the sea more slowly, not more swiftly which is what the water management has been trying to do all these years: then the land can cope and the bonus is it’s better for fish.

    • MikeW says:

      tj. I fear you don’t understand just how much water comes down on the land when it pours continuously. Take the Somerset Levels a few years ago. The surrounding hills became totally waterlogged, hence as more rain fell, it just simply ran down the surface of the hills. Yes, better land management can help dramatically….but not that dramatically when that rain keeps on fallin’!

      • tj says:

        Interesting, one minute you profess to be “no expert”, the next you fear people don’t understand in the special way that you understand without even knowing what their experience or expertise is or is not.

        I have stated my opinion and you have stated your opinion, have the good grace to leave insults and supposition out of the equation.

        Additionally, tunnels have been built to take water to the sea quickly (exactly what we have been doing for two hundred years), they are called sewers, it’s what has caused some of the flood problems! The planet has a certain amount of land, if the lands don’t hold enough water then the sea level will simply rise, logically then, the floods will just be moved to coastal areas.

        Apparently most of the UK was covered in forest until about the sixteenth century, so would have supposedly been better able to cope with flooding, even so there are many accounts on record of cycles of catastrophic flooding in the UK especially on the east cost – after all nature is cyclic and throws extremes. A lot of areas were known to be, and were inhabited as, flood/fen areas. As we are probably not going to reinstate that amount of forest or fenland any time soon (especially in view of the massive population growth), we won’t have the natural buffer zones. So, we will have to adapt to flooding (building housing which is off the ground so when floods happen they are less likely to cause damage, like fishing villages used to do, i.e. use downstairs for boat/car storage and upstairs for living quarters, (this doesn’t address sewerage in flood conditions) and/or have a lot more land soaking up the water (flood planes with no concrete/housing), as well as slowing down rivers by letting them wind their way to the sea with lots of land on either side instead of channelling them quickly to the sea.

        There is no magic, just logic and adaptation. If we don’t adapt we will die

  6. tj says:

    Additionally, you do realise that the Somerset levels has been a known flood plane for thousands of years I presume, hardly a good example of more frequent or unexpected flooding!

  7. MikeW says:

    Hi tj. Sorry if I came across as some ‘know-it-all’. Certainly didn’t mean it that way. In some other parts of the world, especially the tropics, where they have torrential downpours in their rainy seasons, they have built dry concrete ‘wadis’ to take away the excess water. Watching the TV news about the flooding in Cumbria back in 2013/14 I just thought of the idea to get rid of some of the excess rainwater, before it hit the rivers/sewers, which just simply can’t handle so much excess water. Yes…the other things you mention all help of course. But they say excess rainfall is liable to get worse in the future. We need, imo, to get rid of it before it hits the rivers. Best of luck.

  8. gwyn evans says:

    I think the amount of rain that’s dumped on the UK is due to the amount of the rain forest that’s chopped down every year in the Amazon, the resulting bare ground that’s exposed evaporates quicker and brings the resulting water vapour to the UK on the mostly south westerly winds, in parts of North America they use a type of spiked roller to help water get into the soil quicker, like a lawn spike but on a larger scale, again you have to do it before the rain arrives, another idea would be to plough the land less and use direct drilling, during and after WW2 a lot of soil was washed from hill land that was totally unsuitable for ploughing and the soil was washed into our estuary’s , this can be seen at Parkgate on the Wirral were the river Dee has silted up.

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