Forum home Plants

Gardens to compensate for increased building around me

KatfishKatfish Posts: 56

My garden is below sea level.  This means that the water course is high.  We are working on raising the garden a few inches to try to bring the surface above the water course.

Over the years a few more houses have been built around us and there are a lot of people with water treatment plants (for anyone not familiar with these, they clean sewage water and release cleaned water into the surrounding ground).  Though approved through the required agencies I can't help thinking that the reduction in green space and the increase of water being pumped into the ground will affect the general level of the water course in the immediate area.

I was inspired by an article I read recently on flooding whereby oak trees were being planted to alleviate flooding.  Oak trees had been found to be helpful to hold water when the ground was too wet so it was thought that many oak trees together could help to prevent flooding.

To my point then.  I wondered if I could use planting in my garden to similar effect.  Oak trees being big, I'm looking for any alternatives that might be known to 'hold' water in times of excess water in the ground.  The plants would need to be robust through summer too when the water course is lower and they may need to tolerate drier roots.

At present I'm looking for any suggestions regardless of size.
I have an oak tree on the property boundary and that does appear to be the area where the ground is least waterlogged.  So I'd like to think that thoughtful planting would work in reducing the extent of the waterlogging.

I can't help thinking that I'll give plants a better chance of survival if I know they'll be suited to the conditions too!!!



  • I don't think it will work. The problem is worst in winter, but then the trees will have no leaves so they will not lose water to the air through transpiration, so they will not take any water out of the soil. It is easier to choose plants for your conditions, rather than change the conditions to suit the plants.

  • KatfishKatfish Posts: 56

    I may not have explained it very well.  I didn't mean to change the conditions to suit the plants.  Rather to take plants that will suit the conditions (which I already do) and see if they have the added bonus of taking up some of the excess water in wet conditions.

    It's just a theory at the moment which is why I thought I'd ask about it.

    I may have to hunt out the article I read which was based on work being done in Wales to alleviate flooding.  That is on a much larger scale and I think the concept was around the oak tree having capacity to take up the water and hold it, releasing it back when the ground started to dry again.

    I was interested in whether there were any plants that had a similar mechanism of action whereby they would take water and hold it.

    I must admit its a while since I read the article so am going off memory and I may have got bits of it wrong.  But the gist of the article was that lots of oak trees had been planted and it had been noted that the problem of flooding had been reduced.

    I'm not sure it would work at an individual garden level anyway.  Even if it was possible you'd probably need every household on the street to do it for it to have an effect.  But if I didn't even consider it then it definitely wouldn't happen;)

  • CeresCeres Posts: 2,691

    I can't think that a tree would release water when conditions were dry because it would need all that water to keep its systems running. Willows and alders thrive on damp ground and come in smaller versions that the forest oak so would be ideal for a wet garden.

  • SparklesJDSparklesJD Posts: 344

    I read an article about a Yorkshire community, refused funding for 'official' flood-prevention methods, that researched and did their own, substantially reducing the problem - is that the one you mean?

  • SparklesJDSparklesJD Posts: 344

    Reading it again, it's quite depressing image

    I remember my uncle (a Yorkshireman) telling me years ago, that all the funding for maintaining the moors had pretty-much gone, so no-one cleared the ditches or looked after the plants anymore.

  • KatfishKatfish Posts: 56

    I have finally found the project though I can't find the article that I originally read.  It's the Pontbren project (link below).  I can't find the original article I read, but now I've had a look through the project paper it appears that, amongst other things, the trees have an effect on the soil which causes the water to drain deeper into the ground.
    It is a large-scale project and there are various factors that have been found to affect the flooding issue such as reshaping the rivers, using strips of trees which also block run-off, a 'sponge' effect, etc.  It was the bit about the soil that I think I was harking back to, though I suspect I've either remembered incorrectly or the article I read was misleading about trees holding the water.
    In retrospect I've jumped ahead a bit with my question.  The project findings highlighted areas that could be researched further.  I suppose I'm looking at how these findings might affect something on a much smaller scale.  So my question perhaps should be more along the lines of whether anyone has done any planting and noticed an effect it has had on the water course - good or bad.  I'm wondering if you could redesign a whole garden with a view to suiting the plants so well to the environment that they could have the positive effect of either mitigating the flood effect or at least surviving flood conditions well.
    It's all a bit theoretical, but it's from observations of things that happen just from trying them that we get to find out these things.


  Pontbren CS v12.pdf

  • KatfishKatfish Posts: 56

    SparklesJD.  That isn't the one I was thinking of, but I've just had a quick look through it and they are using similar principles - slowing down the water, building trees, etc.

    The Pontbren project I feel is quite encouraging.  I think the findings show that taking water flow back to how it would have occurred naturally and having trees that would have grown naturally actually helped to reduce the flooding problems.

    My concern stems from, as I said in my original post, increased building and increased water being pumped into an area where there isn't really a lot of scope for it.  It's surrounded by farmland so lots of trees have disappeared from the area.

    I have a small paddock area behind my garden which I'm not allowed to landscape and gets very waterlogged.  I am allowed to plant on it if it is something that could have occurred naturally.  The obvious choice for it would be to plant a meadow, but  I'm wondering if I could do anything with that which have a positive effect on the water logging.  But as I've also said, I'm not too optimistic as I think it has to be on a larger scale to have any effect.  My thought is though that I'd rather do something to minimise the problem rather than make it worse.

  • SparklesJDSparklesJD Posts: 344

    I wondered if there was any scope for you to get together with like-minded people in the area to widen the impact? If you have the time and inclination, obviously!

    Maybe a local horticultural society or allotment owners would be a good place to start. People often want to do their bit, but don't know where to start or aren't aware that even doing something small will help.

  • KatfishKatfish Posts: 56

    I'm starting to think this is a 'Big Dream Small Spaces' project!!!  But hey, gotta start somewhere.

Sign In or Register to comment.