new lawn drainage issues

[James94]

Looking for some advice, prior to starting turfing it lashed it down and one area is still boggy.

We thought this was because it was a low spot, top soil wasn’t up to correct height(hadn’t finished levelling in that part) before the rain hit .Its improved slightly but not enough to turf on and I’m worried even if we could have turfed it this is going to cause further problems down the line, will that area ever be solid or just turn to mush?

The ground is clay, we had 2x2m2 soakaways put in, one each side of garden. Just to help with attenuation in downpours. 

Couple of pics highlight the area.

[IanR]

How about another silver birch in the middle of your yellow circle, that should reduce the issue for most of the year.

 

Otherwise you need to put in some small scale land drains. Assuming the soakaways aren't full and the water pooling is due to the slow movement of water through the sub-soil to the soakaway.

 

From your explanation, if the soakaway is in the corner then a 150mm wide trench to the corner, with some branches off to capture the whole area should do a good job. You could get away with Ø50 perforated land drain pipe set in shingle. The trenches around 350mm - 400mm deep. Put 75mm of shingle in, then lay the pipe in and add more shingle on top, stopping it around 75mm from the surface. Ideally you'd line the trench with a geotextile material, and fold it over on top of the shingle, then the drains won't clog up over time with silt. At the very least cover the top of the shingle with a strip of geo textile and then back fill with top soil.

 

Edited October 17, 2023 by IanR

[Marvin]

Hi @James94

 

Always good to have a fall on the lawn to stop standing water.

 

We found that it was very important to have the fall on the clay below as well. If not the clay underneath will act as little ponds.

M

[Temp]

+1

We are on clay (not the really stick stuff) and even with some drainage it's an issue. The ride on mower leaves tyre tracks when the ground is wet which it is from now until late spring. 

 

Depends how much this bothers you but you might want to look at putting in a serious drainage grid and getting advice on soil improvers from local lawn care company. Might need quite a few ton bags worth.

 

 

 

[Conor]

Assuming this is freshly compacted soil, as the grass grows and nature does it's thing, water channels will develop through the soil profile and natural percolation will start. 

[James94]

Thanks for all the advice,

It maybe a little drastic but I fear a few spells of heavy rain will flood the garden so I’ve chosen to install another soak away. But before I complete it is it worth incorporating some sort of access point to enable pumping water away as I’m worried it won’t soak away fast enough under prolonged rains.

I was first of all thinking a 300mm drain and  a puddle pump or just a 110mm pipe connected to crates and hose in to pump away, do you have any thoughts?

Here is a pick after 1day of heavy rain.

Regards. Scezy

 

[markc]

If you put a sump and pump in, where will you pump it to?

[James94]

At the moment we have pumped it out to the site toilet which is at the front of the property which is connected to the in-laws main sewer. I know this won’t be there for ever and pipes will go but there is a drain just before the main road which both of our waste leave via, I was maybe thinking this but it’s a long  way to go.

question is 110mm or 300mm sump, would it make much difference?

Regards. Scezy

[Alan Ambrose]

>>> We found that it was very important to have the fall on the clay below as well.

 

@Marvin How did you do this please - by taking off the topsoil, grading the clay and then re-instating the topsoil?

[saveasteading]

A pond is good. It provides storage, then a big bottom surface and some pressure for soakaway, and evaporation off the surface. 

As above, a tree will dry out the clay in summer, and create fissures. Ditto perimeter plants. 

Any overflow mustn't be towards the neighbours.

 

[Conor]

2 hours ago, James94 said:

At the moment we have pumped it out to the site toilet which is at the front of the property which is connected to the in-laws main sewer. I know this won’t be there for ever and pipes will go but there is a drain just before the main road which both of our waste leave via, I was maybe thinking this but it’s a long  way to go.

question is 110mm or 300mm sump, would it make much difference?

Regards. Scezy

You can't pump surface water in to a drain unless you know where it's going and you have consent to do so. I think looking at your topography, high water table and soil, you'll have to learn to live with it. You've created a large, flat area with minimal vegetation, a bit of creative landscaping will do wonders.

[Mr Punter]

Another vote for a pond and associated planting.  Good for drainage and biodiversity and the garden looks big enough.

[Marvin]

9 hours ago, Alan Ambrose said:

>>> We found that it was very important to have the fall on the clay below as well.

 

@Marvin How did you do this please - by taking off the topsoil, grading the clay and then re-instating the topsoil?

Hi @Alan Ambrose

 

Stripped off the topsoil and part of the clay leaving the ground slightly sloping and replaced the topsoil. However the garden was not very big.

 

We also found that planting large plants in the boarders meant that in the winter their roots sat in ponds and for example all the lavenders died.

 

M

[Gus Potter]

I would go for the pond and plan your garden and wildlife around that. Get that right and you will reap the rewards in terms of habitat and the enjoyment that follows.

 

See once you get your hands dirty,  playing with the water and clay.. making a pond.. you'll feel so good but as an adult you can admit that! but if you have kids.. it's called transferrance.. family fun all round.

 

You can have the odd raised dry area say a deck.

 

Try the pond thing first.. and report back.. in year or two.. it's like the outdoor nurseries where the kids and you get to be yourself.

 

 

[Mr Punter]

15 hours ago, Marvin said:

all the lavenders died

 

They like well drained soil and sunny position.  Wet clay is a no-no.