Draining a small lawn

almostover

Bought a Semi D house late last year in a new estate. Has a small back garden, approx 14m x 7m. Drainage was poor last autumn when we were snagging and the builders dug up the wettest part of the lawn and relaid it to close the snag off. That's didn't really solve the issue when we have persistent rain for weeks and the garden gets very swampy. Was fine for most of this year due to good weather. I was watering the grass at times during dry spells this summer and I noticed than even then that the water was slow to drain down through the soil.

I also ordered a shed at the start of the summer but the company couldn't fit it until recently. The lawn was very swampy from all the rain we've been getting down here in Cork. Unfortunately, the lawn is now a mud bath - see attached image. Not the fault of the shed company, they could do nothing about it and I wanted the shed fitted now rather than having to wait until next Mar / Apr.

When we were digging out at the back of the garden for the shed base we had to hire a 1ton mini digger. There is savage rock under the lawn and the soil seems to have a lot of clay in it. Judging by what's coming out of the ground in the rest of the estate as the other phases are under construction, that's just the soil conditions in this area. We put 4in of hardcore under the shed base but joked that they was no need given the rock present in the soil. We also dug a trench for an armoured cable to run power to the shed which also uncovered similar soil conditions.

The garden is a mess and can only be traversed with wellies. The mud also smells foul, and internet research has highlighted to me that's due to anaerobic soil decay because of a lack of oxygen from the waterlogging. I have 2 questions for those on here more knowledgeable on gardening and landscaping than I am.

1. Is there anything I do short term to get the surface water to drain away? Maybe spiking the garden with a dung fork? Or something similar? I just want to be able to put down a few scraps of plywood on the ground that I can use as a path to get in and out of the shed. Currently it's like crossing bogland.

2. What are my options to fix the drainage long term? Money is tight post shed construction so I'd like to avoid getting a landscaping company in. I'm not afraid of getting stuck into the digging required and can hire a digger again if needs be. I have no viable drain to divert water to other than those in the footpath at the rear of the house and I'd like to avoid digging up the footpath and cutting into the drain pipes if I can at all. Are there alternative drainage options available to me that I can tackle next spring?

Any help or input would be much appreciated!

20221105_134533.jpg

blackbox

The water has to go somewhere.

It sounds like using the drainpipes is the only option.

You will also need to make the soil porous to allow the water to pass through. Lots of organic matter is the best solution.

standardg60

Realistically there is no other option other than connecting a drain to the existing storm drain, there is simply no drainage due to the rock so forking it won't do anything.

Only came across something as bad once, removed all the soil, cut a channel in the footpath to the drain and installed a pipe, levelled the whole area with hardcore and laid out artificial grass instead.

almostover

https://www.boards.ie/discussion/comment/119883922#Comment_119883922

I'll lift the AJs in the footpath adjacent to the lawn at the weekend so and see if any are suitable to run a drain to. Would French drains be an option? And run them to one area of the garden?

almostover

https://www.boards.ie/discussion/comment/119883949#Comment_119883949

I'll have a look at the weekend and see if there's any suitably located drain in the adjacent footpath that could be used. Guessing French drains are out of the question?

Just for the next couple of months is there anything that could be done with regards to spiking to relieve some of the waterlogging? It'll be the spring before I can do a more permanent job on fixing the drainage.

standardg60

https://www.boards.ie/discussion/comment/119884380#Comment_119884380

Be pretty pointless running a french drain to one area of the garden if that doesn't drain either as it will just back up with water and you'll be back to square one.

Pretty straightforward to cut a channel to the drain, dig a hole beside the footpath and you'll see how deep the concrete is, shouldn't be more than a couple of inches.

For getting to and from the shed i'd just dig out a path and fill it with hardcore for now, be wet but at least clean.

zg3409

Water flows down hill. Ideally lowest part is a drain.

There are certain soil types such a marle that don't let water flow through easily.

You probably need a path to the shed like most houses. Grass is not a path.

Recently we have had very un usual amount of rain. This is not normal and may not happen for another 10 years.

Lowering level of grass or making grass higher may push water on to grass or off grass towards drain.

In my case I installed porous tarmac which means all parking area is a massive filtered drain, and installed a small drain at lowest point as a backup for extreme weather.

A large "french" drain at lowest point may be an option. You need water to flow down hill to an existing drain somewhere.

If the soil cannot absorb the water then it needs to go somewhere else.

10-10-20

What soil depth do you actually have? Are your neighbours just as bad or have they previously raised their gardens, making yours worse?

Suckler

Dig a hole, about a 1.5m deep 1.0m square, fill 1.0m of it with clean stone. sand on top and then put soil back over. Some permeable drainage pipe in gravel piped to this soak pit will help other areas as well if needed.

almostover

https://www.boards.ie/discussion/comment/119886786#Comment_119886786

Little or no depth before the soil is a mixture of soil, rock and stone. I'd say 1-2" maximum. All the neighbor's gardens are the same!

almostover

https://www.boards.ie/discussion/comment/119886861#Comment_119886861

A soakage pit essentially? Might be the best option! I'm toying with the idea of putting down fake grass too once I've the place drained......

10-10-20

https://www.boards.ie/discussion/comment/119886861#Comment_119886861

That's hoping that you break past the hard-pan. But what if the sub-layers are just rock, then you have no soakage anyway as you're at the top of the water-table...?

A test-hole might be worth it, but it's going to fill as fast as you can dig it.

almostover

https://www.boards.ie/discussion/comment/119887256#Comment_119887256

I'll try dig a test hole on Sunday and see how that goes, I can fill it with water and cover it and see how fast it drains, if at all. If it helps describe the situation im facing, the garden was lovely and dry during the summer but if we got some heavy showers after a dry spell the water would sit on the lawn for a little while before draining so I'm guessing soil compaction is an issue. I'll dig the test hole Sunday and take pics. Maybe that will help someone here identify my issue.

standardg60

https://www.boards.ie/discussion/comment/119887256#Comment_119887256

Exactly, unless you've broken through a pan which was preventing drainage a soakaway is the equivalent of filling a sponge filled glass with water, then emptying it into one filled with stones and expecting it to hold the same amount.