How to install drainage for surface water on lawn?

[DSollis]

Hey all, 

We recently purchased a property and now need to tackle the garden. It's a very small space so luckily it won't take too much work, but we first need to address the drainage as it gets very boggy after heavy rainfall. The soil is largely clay based and there's no natural drainage so it's pooling in certain locations. We have already had a drainlayer come and install a cesspit connected to the stormwater drain for the runoff but I had asked about doing the sub-soil drainage myself to try and save some money as we have quite a few things to do. He did give me the basics of the work required and said doing it myself would be more than achievable, but with all projects I want to make sure I've done as much preparation as possible and any help would be greatly appreciated,

 

I feel that I have a basic understanding of what's required but want to make sure I've not missed anything before I start digging. I have attached some pictures of two locations where it's especially bad to give an idea, but once this work has been done we will be raising garden beds and filing with appropriate soil for some veggies/plants. There is a large pile of dirt which I have yet to clear from the original first dig for cesspit. I have already received all the local plans for the area and there are no services/lines underneath the ground where I intend to dig either. 

Would I just need to dig a trench in the applicable areas (where water seems to collecting and at the base of hill slope) and line with geotextile fabric, aggregate and a slotted pipe? I will save the turf to lay back on top afterwards. I had intended to run one pipe down the side of the property which would be connected via Y bend to meet the other pipe before finally connecting through the cess pit (with appropriate slope drop). I have watched various videos online regarding subsoil drainage and they all seem to suggest the same concept but any further advice would be fantastic! 

Thanks in advance

[EricL]

Hello @DSollis

Welcome to the Bunnings Workshop. Thank you for joining us and sharing your question about installing drainage for your lawn.

The steps you've lined up are exactly what you need to do to create your drainage. I recommend observing the fall of your drain when you dig your trench. Your goal is to make sure that water flows out of your drain and into the area you want it to go to. If you dig too flat the water will tend to pool in the drain. If there is too much clay in your topsoil, your other option is to leave the turf off and leave the channel open like a french drain. 

Here is a link to one of our featured projects: Drainage to fix a muddy lawn by @Ben

Let me tag our experienced member @Adam_W for his recommendations.

If you need more advice or information, please let us know.

Eric