How to add backyard drainage to waterlogged lawn?

Leenamalhi

Hi , I am using Bunnings workshop for the first time but have been reading posts , so thought I can get right advice here. I have moved into this 15 yr old house about 9 months back. Lawn in my backyard is L-shaped, I’ll attach photos, houses at the back are about 75cm higher. When it rains, water stays in the lawn making it muddy , looks like there is no drainage. My dog keeps bringing mud into the house. I need advice how to put drainage in. Would AG pipes work and can they be joined to existing stormwater drainage. Please give your opinion ( in details) as to what should be done. Thanks . 

JacobZ

Hi @Leenamalhi,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

Yes, AG pipe is a suitable solution for your drainage issue as long as it is installed correctly and has a proper point of discharge. The most effective placement is likely along the rear boundary where water is entering the yard from the above neighbours, as well as along the lowest part of the lawn where water naturally collects. If you take note of where the soggiest patches are in your lawn, this can certainly give you a good idea of where it would be most effective.

To install the AG pipe, dig a trench approximately 300mm deep and make sure it has a continuous fall towards the discharge point. A fall of around 1:100 is ideal, meaning 1 cm of fall for every metre. The fall of the pipe is critical, as without it, the pipe will hold water instead of draining it away. 

Line the trench with geofabric, leaving enough material to fold back over the top later. Lay the AG pipe into the trench with the slots facing down or to the sides. Surround the pipe with drainage gravel, making sure there is at least 50 mm of gravel above and below the pipe. Fold the geofabric over the gravel to prevent soil and silt from entering, then backfill with soil and reinstate the lawn. 

Check out How to install garden drainage for an easy-to-follow step-by-step guide.

Your AG pipe can then be connected to existing stormwater pipes; however, this connection must be made by a licensed plumber. If there are stormwater pipes available, attaching your ag pipe to them is the best approach, as it will ensure the water drains to existing council infrastructure.

Let me know what you think, and if you have further questions, please don't hesitate to ask.

Jacob