How to stop backyard flooding?

danesha24

Hi everyone, we have a problem with our backyard. When it rains, it basically becomes water world out there. It’s a high content of clay and once its been raining for a bit, it floods. Our brick undercover area floods in parts as well. We purchased our home after renting it for years.

The rain floods down the side of the house, despite having a roof over the undercover area. There is a drainage spout but for some reason the previous owner blocked it over. We want to extend the undercover area but we need to work out how to stop the flooding in the yard and undercover area.

I’m attaching pics from a couple of weeks ago, it rained consistently for one day but it took 4 days for the water to disappear. We really want to enjoy outside and we have heaps of plans.

Please tell me your ideas of how I can divert water and fix the undercover area so we can use it. Thanks :)

JacobZ

Hi @danesha24 ,

Looking at the extent of the flooding and the fact that the water is also making its way into the undercover area, I suspect this is unlikely to have a single solution. You will likely need a combination of surface and subsurface drainage to get the water under control.

For the lawn and other areas where water is soaking into the ground but can't drain away effectively because of the clay, agi pipe installed in gravel-filled trenches could help collect the water and carry it away. In areas such as the side of the house and around the undercover area, channel drains would likely be more appropriate for intercepting surface water before it reaches these areas.

The blocked drain you've mentioned is also something I'd want investigated. If there is an existing stormwater connection there, understanding where it runs and why it was blocked off could be an important part of working out the overall solution.

With this amount of water, I'd suggest speaking with a licensed plumber who works with stormwater drainage. They can assess the levels around the property, investigate the existing drainage and determine where any new agi pipes and channel drains can discharge. Once you know where the water can be directed, it will be much easier to put together a plan for the yard.

I'd definitely get the drainage sorted before going ahead with your plans to extend the undercover area.

Have a look at How to install garden drainage and How to fix a muddy lawn. They give a good overview of the different approaches to managing surface and subsurface water.

Also, allow me to tag some helpful members to see what they might do - @Dave-1, @Nailbag, @Noyade.

Let me know if you have any questions.

Jacob