Garden is a bog - land drainage ?

[andy6581]

Hi All


I'm after some advice.

My next big project is to sort out the garden of our new house. We only moved in OCtober, so now the weather is starting to perk up a bit, i'd like to try and get something sorted for summer, and ready for the arrival of our first baby. As you can see from the photos, it's a complete bog, which is impassible without wellies!


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I am surprised, as behind the fence (marked in white) is the bank of a brook, which is about 2-3 metres lower (marked with the light blue line below in the aerial shot). I wasn;t expecting to have any drainage issues! There's no public access to the banks of this brook, as it's locked in by houses, so it;s mainly bramble covered.

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The aerial shot shows our house boundary in Red (With the fence that borders the bank of the brook in White). The House to the left , bordered in yellow, has extended his boundary, and essentially encompassed the banks of the brook into his garden. I suppose i could do the same at some stage if i wished, but i digress!

I have dug a few exploratory holes around the garden, and it seems that there is about 8 inches of topsoil (Mud) and then solid clay. I've not got down further than about 2ft yet though. The holes i have dug have filled up to around the top of the clay, but i guess that doesn;t really tell me much, as the holes are now essentailly big clay buckets. The lawn is dead, as i used roundup on it when we moved in (full of weeds). It's grown back with a quite a few weeds.

I've been reading up on land drainage, and did a small french drain at another house.

My Plan is to :


Get a Micro Digger for a weekend!

Dig 3 large trenches and use 100mm land drains covered with gravel to a soakaway (hoping i can get past clay) which i will position on the border with the brook somewhere (near the white fence). I will also dig smaller herringbone trenhes that go into the larger trences, but just filled with smaller gravel.

A Couple of questions

I think i need to ship in about 5 tonnes of topsoil, as the lawn could come up a few inches. Should i also be using sand on top of this before i returf to help the water move accross the surface to the drains ?

Can i dump topsoil on top of the old dead grass, or am i better to try and remove all the old turf [edit as the swear filter didn't like s0d ] , or rotivate it all in ?

I'm not sure whether i'm technically allowed to drain off into the brook ?

I've read mixed reviews of the geo-textile material, and whether to line the trenches. Can anyone offer any pearls of wisdom ?

Thanks

Andy

 

[Static]

I would connect your land drain to an outfall to the brook as the chances are a soakaway will not work at all.. you will need to contact your local authority for concents etc..

 

[Arthur2shedsJackson]

My back garden has a similar problem, although not as bad as yours, in fact your pictures have cheered me up and I wonder what i'm worrying about!!


I have heavy clay soil and I would agree with the previous poster that soak aways will most probably not work.

When you get the top soil I would make sure that you are very selective, as you don't want any clay in it.

As for the sand, perhaps you could use sharp sand and mix some grit into it and the top soil that you use.
I believe it's a matter of getting the water away from the surface as soon as possible.

As regards running the water into the brook, do you actually need permission ? In theory, that water should be running into it anyway !!

Good Luck

 

[andy6581]

I will probably dig a soakaway anyway to see if i can get past clay, and just make sure that it has an overflow which goes out to the brook as well.

I did wonder whether i needed permission to run off into the brook, as that is technically where it should end up anyway, i'm just trying to help it along a bit .

Although my deeds show the fence as my boundary, having done a bit of research this morning, i do wonder whether i am the "riperian owner" of this small part of the brook.

http://en.wikipedia.org/wiki/Riparian_water_rights

http://publications.environment-agency.gov.uk/PDF/GEHO0407BMFL-E-E.pdf

Thanks Andy

 

[Arthur2shedsJackson]

I think the soak away with the overflow into the brook is ideal, and what I would have suggested, it gives you two attempts at getting it away

 

[merlin50]

if water never entered the brook it would dry up sometimes it need a bit of help

 

[bell824]

i have had similiar issues with my garden,

i have now finished the herringbone drainage with 80mm pipe dug down to about 500mm and filled with 20mm clean aggregate,

I am now in the process of removing around 50mm (including old lawn) from the crappy clay soil that was under it.

I am now about to order my top soil for recovering it all but am now wondering if i should line the area with stone to give a water table run off into the drainage or just level it off and add topsoil!!

i am thinking put a thin layer of 20mm gravel and then 3 inches of topsoil and seed it of, any one else got a better idea!!

 

[r896neo]

I wouldn't bother you don't want to drain it too quick either.

 

[andy6581]

Thanks All. I'm going to start digging this weekend to begin the layout. I need to make sure i'm competely ready when i get the mini digger, so really need to get all the topsoil etc on site.

 

[TheSalad]

Good luck!! Let us know how you got on . . . . with some pics too!!