How to improve backyard drainage?

Skimmo24

Hello experts!

Seeking some advice in relation to sorting out drainage issues in my enclosed courtyard area.

I was thinking of doing a french drain as per the photos attached (red line with yellow marks would be slotted pipe). This would connect to a storm drain located just outside of the enclosed area.

I would be looking at digging a 100mm deep trench, filling it with geotextile and drainage rocks before laying the slotted pipe. 

In relation to connecting this pipe to the stormwater drain, will be using a plumber to make sure this part is done correctly.

An alternative option I thought of was drilling weep holes through the enclosing walls to allow water to drain outwards. The enclosed area is slightly higher than the grass outside.

The entire courtyard will eventually be covered in synthetic turf.

Would this idea work? What other solution options do I have?

Thank you!

JacobZ

Hi @Skimmo24,

Thank you for your question about drainage in your courtyard area.

Your first solution of adding a French drain connected to your stormwater outlet is, in my opinion, the better of the two. Mainly because the water is being channelled to a system designed to carry it away to a suitable location whereas drilling weep holes in your retaining wall is just moving the issue to another location.

While this is the better of the two options, I would make two slight tweaks to your plan.

I'd suggest adding an additional French drain to the right side and the far end of your courtyard as I've shown below.

This way, all the important things are protected from groundwater and while you have the opportunity before turf goes down, it is worth futureproofing as much as possible.

The other tweak I would make to your plan is to dig your trenches deeper. Ideally, your French drains should be around 300mm deep, so they sit below the level of your home's foundation. The idea is they will capture any groundwater above them and any water that seeps through the earth to a level below them will dissipate into the earth well below the level of your house foundation.

Allow me to tag @TedBear, @JoeAzza and @Nailbag to see what they think.

You might also like to check out How to install garden drainage for some guidance.

Let me know if you have any questions or thoughts on my recommendations.

Jacob