How to fix backyard drainage issue?

[felipenm]

Hey all, I am looking for ideas on how to fix a drainage problem I have. As you can see in the photo this area gets “flooded” whenever there is heavy rain. A Deck will be built in this area and ideally there should be minimum water sitting there as possible. 

So looking for idea on how to address this issue. 

Thanks! 

 

[JacobZ]

Hi @felipenm,

Thank you for your question about addressing drainage issues in your backyard.

As your yard appears to slope towards this area, any water in your backyard appears to be collecting in this low spot. Having this happen underneath a deck is definitely not a good thing, so a good drainage system is going to be important.

The solution will involve a combination of things. 

I'd suggest having agi pipe installed around your yard and connected to a stormwater outlet by a suitably licenced plumber. This will help collect some of the water before it drains to this low point in your yard. Check out How to install garden drainage for a bit of guidance on this.

Stopping as much of the water before it gets to this area is a start, but it's still likely you'll have water draining to this low point. Alongside the agi pipe, installing a stormwater pit in this area to collect the water with a sump pump to pump the collected water to your stormwater pipe is also going to be essential.

Any connections that are made to a stormwater pipe will need to be done by a suitably licenced plumber, so it is definitely worth speaking with a plumber in the planning stage for your drainage project. As they will likely be a necessity, it's worth having them evaluate the area and make recommendations on where to locate components for your drainage that will best manage the water in your yard.

Allow me to tag @Nailbag, @Dave-1 and @Noyade to see what they think.

Let me know if you have any further questions.

Jacob

[Dave-1]

Afternoon @felipenm 

Looks like you have a free pool 😕 Have you dug out that area yourself?

I would strongly recommend about allowing any free standing water under a deck. There are so many issues that arrise from that and the first one is mossies will love your place.

Contacting a plumber would be a good starting point due to the amount of water you have. I can see the retaining wall and the slope of the ground so that would add up to a fair amount of water coming down slope and probarly would be better to manage then not.

I would go as far to say that a grill drain and possibly a large grill drain may be an idea. How far does the hill go up?

The other question I have is what is the red marking on the pillar for?

Dave

[felipenm]

Thanks @Dave-1 and @JacobZ, I have already contacted a few plumbers to analyse the situation and provide a solution.

The water pooling area is actually the level it was handed over by the builder. That higher ground was filled with dirt taken from the pool hole, probably not a good idea.

The red mark is the termite barrier as the deck will be up to that level.

I have also been thinking about the grill drain and a retaining wall. The grill drain, positioned correctly, would then connect to the stormwater, and the retaining wall with geotextile and gravel alongside an agi pipe or French drain on the outer side would also lead to the stormwater. 

Felipe

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[JacobZ]

Hi @felipenm,

Was this area left lower by the builder to accommodate the deck? Or was the rest of the yard just raised by the pool excavation causing this to be a low point?

If it can be filled, it might be worthwhile having an earthworks company do a site cut and move some of the excavated soil in the upper yard into the hole where the water is pooling. If there is not an obvious slope, the water will soak into the soil more evenly instead of running off to the lowest spot.

You can then install the above-mentioned drainage solutions as part of a more holistic drainage plan for the yard.

Let me know what you think.

Jacob

[felipenm]

@JacobZ , the rest of the yard was raised by the pool excavation causing this to be a low point. That might be a solution, I will have to contact those companies to see what solution they will come up with.

Thank you!

Felipe

[EricL]

Hi @felipenm 

Please keep us updated with your progress, we look forward to seeing your drainage issue sorted out.

Eric

[Dave-1]

Evening @felipenm 

Thank you for the extra information The grill drain (once you have your yard leveled out to be consistant across the whole yard plus the temp pool area) should really carry the excess water to the stormwater and then its gone so wont pool anywhere. You may not need an ag-pipe but still it could help with over all drainage. 

Dave

[felipenm]

Hey team, @JacobZ @EricL @Dave-1  I've got a plumber to address the issue. They will have drains in the right position to capture most of the water and run it off to the stormwater. I am thinking of putting a layer of something on top of the current soil (clay) to help with the drainage and divert water to the drains from the house. so the question is, what would be the best material to have on top to have a small fall, a type of soil, gravel, or something else?

[JacobZ]

Hi @felipenm,

A layer of drainage gravel is the ideal choice for this as it can be compacted but will still have channels between it that will allow water to flow between the stones.

You can lay down some geotextile fabric or weedmat followed by a layer of drainage gravel approximately 100mm thick.

Alternatively, if you can use decorative stones to achieve a more pleasurable aesthetic.

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

Jacob