[Digger Dan]

Hello,
I want to solve a problem with a badly waterlogged lawn. The soil is a heavily compacted clay and water stays in pools on the lawn for days after last rain. Lots of moss, lost of weeds and very little lawn grass left.
From research on this site and others I think I have what I need to do sorted, but I have a couple of questions. Maybe someone can advise?

1. Should you put some stone in the trench first and then the pipe or put the pipe in first and stone after?
2. Should the mypex (ground cover) be on all sides of trench or just cover the top?
3. I estimate about 100m of channel needs to be dug, would I be mad to try this by hand with drain spade? Is a mini digger the only option (Note: I don't want to make a complete mess of the lawn with a digger, also trying to keep costs down)
4. I'm planning to use a 80mm land grain pipe, but some sites recommend 100mm. Would 80mm work ok?
5. I'm planning to dump any soil I dig out and fill trenches with good quality topsoil. What should I look for in topsoil and who delivers to Wexford?

I've included a sketch of the drain channel I hope to build, welcome any comments?

Rgds,
Digger

[James Kilkelly, was GPI.]

[Digger Dan]

Thanks for the answers,
I'll probably go with the mini digger for the main channels and keep hand digging to a minimum!

I was thinking of using a petrol scarifier to clear off the moss, do they work?

I was also considering hiring a lawn aerator to work on area between drainage channels. Would this be a waste of money and should the drainage channels be sufficient?

Sorry about all the questions but hoping to get the job done during Paddys week.

Rgds,
Digger Dan

[Michael196]

Dan

I am in Castlebridge. I undertook a similar project about three years ago, and I am glad to report it was sucessful. ( didnt use mypex or the drain pipe though ).

I did hand dig it, but it was maybe 30 meters, and I had to go down about a meter to break through a layer of solid type soil.

my draininge problem was caused by the diggers working at the construction of the hedge mound, compaction caused by the diggers left a similar problem to what you are decribing. There was also a distinct triangle shape to where poor grass grew, and where poor draining existed.


Digging out did take forever, so I realy recommend a mindigger as GPI says.

Look at the People newspaper or similar for topsoil, usually is available.

do you know how much stone you will use ? I reckon maybe 3 tonne for a job your size.

would you consider mixing the soil with conditioner ( mulch / compost ) to make a raised vegtable plot ?

scarifiers do workwell, but I think it may be a little early for scarifiers , maybe april ? The damage to the lawn from a scarifier used too early will result in patchs of bare ground that may not fill in over the summer.

you may need to kill the moss first using iron sulphate I think? chekc in any garden center what to use to kill moss.

I think O Rourkes in Castle brige have small draining stone.

I dont think you need the lawn areator at this point.

[Humanoid]

Rather than use a mini digger why not try a trencher.
They will trench down to 7 inches which is probabaly enough for a lawn but will save your lawn from further damage and compaction from using heavier machinery.

[Digger Dan]

As the saying goes 'on mature reflection' I decided not to go ahead with installing drainage channels to solve my waterlogged lawn problem. Thanks to all who contributed to this topic. A couple of reasons to put a halt to my gallop!

1. Cost in time and money. I looked at the option of doing it myself and getting it done 'professionally'. The price I was given for getting the job done ranged from €1,300 to €3,600, a wide spread for the same spec! The biggest cost to me would be time. After having dug some drainage channels for my vegetable plot I realised that to try do this by hand for the whole lawn would be back breaking (and take days). I could hire a mini digger for €150 per day but I used one of these little monsters a couple of years ago to dig out a foundation and the 'collateral damage' they do would still leave me with a lot of work to do by spade.

2. Benefit. From all that I read it would suggest that putting down drainage channels alone would not give me the desired result, i.e. a lush green well drained weed free lawn. In reality the existing groundcover (not grass!) would need to be sprayed off, the top 100mm rotovated, some sandy loam mixed in, levelled and reseeded. Then the excess water could freely pass through the grass layer and drain away through the channels. Simply putting in the drains would still leave me with strips of the existing poor quality lawn, albeit drier. In effect I'd end up with a dry bad lawn as opposed to a wet bad lawn! This was now looking like a very big job for a hobby gardener!!

3. A better bang for my buck! I looked again at what was causing the persistant wetness on the lawn. The lawn isn't perfectly level and there is probably a 50-100mm difference from the higher parts to the lower part, the lower part being near the centre of the lawn. This lower part is where the water tends to pool but all parts of the lawn stay very wet and 'spongey' after rain. To me this suggests that there is also a problem much closer to the surface. The rain doesn't even permeate the grass layer let alone soak into the soil. This is probably due to the fact that over the 10 years since the lawn was laid there has been a build up of a dense layer of thatch. So taking into account what might be the best job and what can be done in a reasonable time and cost I'm going to tackle the problem in a different way.

So here's my plan!!

i) Kill the moss. I've applied sulphate of iron to kill off the dense mat of moss. This 10KG container cost €15 and covers 350 sq m approx.

ii) Apply a strong lawn weed killer to kill off as much of the 'non grass' vegetation as possible (suggestions welcome!)
iii) Hire a scarifier (€40/day) and clear off dead moss, weeds and thatch. This would also open up the top 10-15mm of the soil.
iv) About week after scarifying use a hollow tine aerator. These pull out plugs of compacted soil and create a shallow 'soak hole' across the whole lawn.
v) Scatter a ton of coarse sand over lawn (€50) and rake into holes
vi) Purchase a ton of good sandy topsoil to level out dips in lawn and fill in aerator holes
vii) Scatter with lawn seed, water and watch it grow!!

My plan is to increase the permeable depth across the lawn. Ultimately the soil below the new 'aerated zone' will be as impermeable as ever but I will have created a signficantly larger soak hole for rain, thus allowing more time for it to evaporate before pooling visably on lawn.

A quick calculation I did shows that with 100m of drainage channel (400x150mm) I would have a soak hole of 6m3. If I aerate the whole lawn (20m x 15m approx) to a depth of 100mm I would get a soak hole of 30m3, 5 times more!

The big attraction to me is that the lawn is never out of commission and it doesn't make a difference if I miss a week between stages. But I should end up with a better looking lawn. Stay posted!!

[sdietz]

I've read through all your answers and appreciate all of the answers. Especially determining the sort of soil you are evaluating (sandy, clay, or loamy)

[NewGuy]

Hi Everyone,

Just wondering if anybody can advise me on my particular drainage problem.

My house is a relatively new (3 year old) mid terrace house, and has a small rear garden (approx 5m X 8m), The builders provided a fully landscaped garden more or less as seen below. The garden has come along well with the exception of one area, the rear corner of the garden which has always been a little soggy underfoot but still supported plant life.

Last year my next door neighbor told me that he had a similar problem and that the builders had offered to sort it out for him. I opted to have the builders do the same for me. I was away when the work was completed but to the best of my knowledge, the builders came and dug a couple of small bore holes in the affected area and filled them with pea gravel.

Recently I wandered out to plant a new tree (black bamboo) and noticed that the ground was softer than before with water now visibly oozing from the surface. I decided to dig and investigate. I dug down a pit approx 3 ft X 3 ft X 2 ft deep as seen in the picture below. The soil was extremely soggy, what I would describe as "sticky mud pie" consistency There was a little water on the bottom at the beginning but after a day or so (with no rainfall) the level of the water increased to nearly 1 foot deep. It has remained at that level more or less since then (nearly 2 weeks).

I am trying to figure out my next step. The builders are long gone and I somehow doubt that I'd be able to get them back. So should I get professional assistance or is this something that I could do myself. Something like described in the other posts above? Perhaps hire an Earth Auger and dig another hole myself or is this a symptom of a bigger problem. I was planning to move the shed from its current position to where i've dug the hole so perhaps I should just fill it back in with stones and mud and bury the problem. Lots of questions, I hope someone can help.

Best Regards

NewGuy

[NewGuy]

Forgot to upload the photo of garden......

[Liparis]

Get your solicitor onto it. You need that sorted out. It sounds to me as if your gardening a few inches above the water table and that is not a problem that will go away if you hide it. My main concern would be what's happening under the house if that is the water table.
Maybe it's a spring, but whatever it is it needs to be looked at quickly. Your fencing will rot, as will your shed, your going to have appaling problems when each winter comes in, it will get worse each year. The people responsible need to be back sorting it out.
Perhaps it's the point where all the land drains to, if so, it needs to be rectified and digging a hole and filling it with gravel is a joke.
I helped someone with a similar problem, the house was 20 years old, but it turned out to be the responsibility of the builders. They had to come back and put in drainage systems to take the water away,they had been guilty of draining all the surounding plots to that point, but I can promise you, it wasn't even 25% of you problem.
After only 3 years the builders should be easily found.
Bill.

[NewGuy]

Thanks Liparis.

My neighbour tells me he was told that a land-drain runs along the back of the gardens..but surely this should take water away from the area...seems that a number of houses have the same problem although they havent dug down to investigate as i have.......I'll get onto the builders first thing.

Regards

NewGuy

[Liparis]

[Digger Dan]

With the prospect of another wet July I decided this job couldn't be but off any longer.

I set about digging out the channels using a trench spade along the lowest points on the lawn where the water usually pooled after rain. I dug 30m of trench approx 350mm deep and 150mm wide. It was easy to see that the fall was right as the ground was so wet that the open channels quickly had water in them.



I put in a 50mm layer of pea gravel into trench and then put in the slotted pipe which I bought from the local farmers co-op at €1.00 per metre. The pipe was covered with another 50mm of gravel.


I then covered the gravel with strips of Mypex which I hope will keep the gravel/pipe clear of silt etc.



A tip I would give here is to be sure to fill up the channel with good soil and not put back in the poor draining soil that you took out! I used the soil from the vegetable beds. I leveled off the channels, cleared rest of lawn of dig spoil and reseeded with a No.2 lawn seed. A few weeks later you can see strips of 'good' well drained lawn!


The drainage channels are working and after more heavy rain the lawn no longer pools and water runs out of the pipes into an open drain at the end of the garden.



However, apart from the strips of 'new lawn' the rest of the lawn is drier but still in poor condition. Some more work needed to turn the weeds to grass!!

Using a spade to dig the channels by hand didn't turn out as much work as I thought. Using a minidigger would have made a complete mud bath of the whole lawn and would have taken significantly more effort to get the lawn back into shape. Also the digger tracks would have compacted more an already compacted soil. But if anyone is going to do this by hand be sure to use the right spade! A trench spade is narrower and longer than a traditional spade and is easier to lift out sods to the right depth. I also modified an old rake head to a width of 150mm and fitted a stong handle. This was very useful in getting into the narrow channels to clear stones/sods and for leveling out the gravel in the channel.

___________________________________________________
Digger Dan

[Bullaun]

great job!
I'm going to embark on a similar project myself soon...

Looks like it worked a treat for you.